Linux “bash: mail: command not found” error fix – Installing mail cli on Fedora, Debian, CentOS, Ubuntu


September 7th, 2018

bash-mail-command-not-found-error-fix-linux-installing-bsd-mailx-linux-fedora-debian-centos

If you just hired a cheap VPS with some kind of Linux OS installed or just installed a home Linux test system environment inside a Virtual Machine (such as VirtualBox) on your notebook and you want to read system email reports delivered by services (e.g. track possible errors with the OS) or simply test whether Email relaying is configured properly

and you end up with shell error:

bash: mail: command not found

because mail command is missing and you wonder what Linux package you have to install in order to have the lovely mail / mailx command back on the OS … this article will help you how you can easily solve it by installing the mailx binary file (e.g. install the package providing it depending on the Linux Distribution Operating System you face the problem on.

1.  Install mailx command on Debian / Ubuntu / Mint and other .deb based Linux
 

root@linux:~# apt-get install –yes bsd-mailx

 


An alternative way to install the mailx system binary is to install  mailutils package

which will set up the system with essential mail related programs and set up a light Exim MTA and common server Email surrounding  so you can easily configure default installed Exim Mail Server to serve as an SMTP relay (through dpkg-reconfigure exim4-config) command

 

root@linux~:# apt-get install mailutils
Reading package lists… Done
Building dependency tree       
Reading state information… Done
The following additional packages will be installed:
  exim4-base exim4-config exim4-daemon-light guile-2.0-libs libgsasl7
  libkyotocabinet16v5 libmailutils5 libmariadbclient18 libntlm0
  mailutils-common mysql-common
Suggested packages:
  eximon4 exim4-doc-html | exim4-doc-info spf-tools-perl swaks mailutils-mh
  mailutils-doc
The following NEW packages will be installed:
  exim4-base exim4-config exim4-daemon-light guile-2.0-libs libgsasl7
  libkyotocabinet16v5 libmailutils5 libmariadbclient18 libntlm0 mailutils

 

root@linux:~# dpkg-reconfigure exim4-config

 

dpkg-reconfigure-exim4-config-debian-linux-exim4-email-server-screenshot

2. Install mailx Linux command on Fedora / CentOS / RHEL e.g. Redhat based distros

 

On RPM based distrubutions the package name is different from debians to install it there you have to fetch and install current distro mailx .rpm

To install mail command on older CentOS / Redhat 7/6/5 distributions

 

[root@centos:~]# yum install -y mailx

 

On Fedora 22+ version yum auto-dependency tool was substituted with dnf:

 

[root@fedora:~]# dnf install -y mailx

 


3. Send Test Email with mail command

 

root@linux:~# echo "Sample Message Body" | mail -s "Whatever … Message Subject" remote_receiver@remote-server-email-address.com

 


Check the mailbox, you just sent the sample email, hopefully if MTA is relaying correctly and the SMTP relay is properly delivering the email should be at the recipient address.

Copy Paste Virtualbox enable between Linux Host and Guest Virtual Machine


September 6th, 2018

enable-copy-paste-between-linux-host-and-guest-OS-virtual-machine-virtualbox-vbox-logo

Copy / Pasting has become a vital part of our digital lifes, not having it in our days is insane, most of our System Administration jobs / Programmer or Office (Secretary) stuff daily without Copy / Paste is a unthinkable.

Lately I have been playing with Virtual Machines as I need to test some Dev Ops related stuff I install Jenkins write and test scripts and tools inside a VM, for that to happen I needed a working VM and because I am a Free Software supporter my VM of choice is usually Virtualbox. Even though Virtualbox is not the best and most performance efficient Virtual Machine out there for a small tasks and home usage dev / testing it does a great job, I have faced a problem with Copy / Pasting not working in VBox between the VM -> Guest OS, that's why I decided to write this step by step guide to help people who face the same issue.

For people who are starting with Oracle VirtualBox and you just have Created a New Virtual Machine and installed GNU / Linux or FreeBSD one common set back problem you will experience is the the Copy / Paste functionality between the VM Host Machine and the Guest won't be working out of the box. That's pretty much annoying thing and since usually one installs different Virtual Machines with different Operating Systems as a test bed for Software installs on top of various versions of OSes the lack of Copy, Paste functionality which is not there by default makes copy / pasting programming code / commands etc. between your local Desktop notebook or remote  server Machine and the VBox Virtualized Guest mostly unusuable …

Besides that integration (sharing resources / improved VM performance) between the Host (which is for example your Desktop notebook or PC) and the Virtualized Operating system be it some kind of UNIX (FreeBSD) etc. is not optimal until you enable an extra integration between VirtualBox and your (Host OS – that in my case is Debian 9 GNU / Linux but it can be Microsoft Windows XX as well or any other *nix like OS).In order for this Integration between your Host OS and Guest OS and Copy / Paste features between the two to work you need to Enable Guest Additions CD image (Software) that is part of VirtualBox installation on the Host OS and once enabled to mount (Attach the Vbox provided Virtual CD) from within the Guest OS (that in my case is another Debian 9 Stretch Linux that is installed inside the VM) and run a script that will install the necessery VirtualBox software inside the Guest OS Linux.
 

This is done in 3 easy steps:

STEP 1: Enable Vbox (Guest Additions CD Image)


virtualbox-VM-enable-insert-guest-additions-CD-image-menu-screenshot-debian-linux

 

Devices -> Insert Guest Additions CD image

 


2. Enable Shared Clipboard and Drag and Drop from the Virtual Machine

virtualbox-VM-enable-devices-shared-slipboard-bidirectional-menu-screenshot-debian-linux
 

Devices -> Shared Clipboard -> Bidirectional

 

 

virtualbox-VM-enable-devices-drag-and-drop-bidirectional-menu-screenshot-debian-linux
 

Devices -> Drag and Drop -> Bidirectional


3. Install development packages that are required by VBoxLinuxAdditions.run script

a) First thing is to use Virtual Box program interface menu and enable Insert Guest Additions CD Image option (assuming that you have the Linux Guest OS running).

virtualbox-VM-enable-insert-guest-additions-CD-image-menu-screenshot-debian-linux
 

Devices -> Insert Guest Additions CD image


http://pc-freak.net/images/virtualbox-virtual-machine-guest-os-settings

You can do it also from main VirtualBox interface (without having a Virtual machine running) by clicking over the desired Guest OS or pressting CTRL + S key combination

b) Next step is to mount the Virtual CD Guest Additions inside the Guest OS VM

To mount the Virtual content provided by the just ticked VBOX "Insert Guest Additions CD" menu, inside the Guest OS Linux, you have to run simple mount command:

 

 

root@debian:~# mount /media/cdrom1
mount: /dev/sr1 is write-protected, mounting read-only

 

c) Install necessery packages that VBoxLinuxAdditions.run will use

Further on VBoxLinuxAdditions.run (additions script) that adds the integration between the Host operating system and the Guest OS depends on some essential tools necessery for building (compiling) / developing software on Linux, this are:

1.) build-essential – a meta package that will install the following set of packages:

 

dpkg-dev fakeroot g++ g++-6 libalgorithm-diff-perl libalgorithm-diff-xs-perl libalgorithm-merge-perl libdpkg-perl libfakeroot libfile-fcntllock-perl libstdc++-6-dev


which are necessery for creation .deb packages, compiling code and other various activitions. a) build-essential is a very important Debian based distro package and if you happen to be new to Linux or just starting learning how to develop programs on Linux, you will soon realize you will need it installed across almost all Linux OS hosts you maintain or develop on …

VirtualBox-VBoxLinuxAdditions-run-script-missing-headers-gcc-perl-how-to-fix

 

root@debian:~# apt-get install –yes build-essential linux-headers-$(uname -r) gcc perl make

 


2.) The linux-headers package in my case that it is is linux-headers-4.9.0-7-amd64 is important as it provides kernel header files that are necessery when compiling and integrating kernel modules VBoxLinuxAdditions.run script depends on it as it builds a kernel module that adds the integration (that enables Copy / Paste and performance inprovements) between the Host VM machine and Guest OS

3.) gcc perl packages this two provides the C compiler and perl scripting programming language interpreter which are also used by VBoxLinuxAdditions.run script.


Now run VBoxLinuxAdditions.run:

As you see in above screenshot the

root@debian:~#
root@debian:/media/cdrom1# sh VBoxLinuxAdditions.run
Verifying archive integrity… All good.
Uncompressing VirtualBox 5.2.18 Guest Additions for Linux……..
VirtualBox Guest Additions installer
Removing installed version 5.2.18 of VirtualBox Guest Additions…
Copying additional installer modules …
Installing additional modules …
VirtualBox Guest Additions: Building the VirtualBox Guest Additions kernel modules.  This may take a while.
VirtualBox Guest Additions: Running kernel modules will not be replaced until the system is restarted
VirtualBox Guest Additions: Starting.

 


If everything is fine you should get command output like above.

Above are the steps given to follow on current latest Debian Linux 9.5 (Stretch) as a Guest OS (this tutorial should be working also on Ubuntu / Mint and other deb package based distributions for RPM package based Linuxes Fedora / CentOS check out my previous toturial how to enable Linux Guest Virtualbox Addition on Redhat based distos.)

P. S.

What about Mac OS X since it is based on FreeBSD and it includes a lot of GNU licensing programs?

If you wonder whether on Mac OS X you don't need to run guest additions script such as (VBoxLinuxAdditions.run) on Mac Host -> Guest OS integration is done only by enabling the feature from VBox GUI interface via:
 

Devices -> Insert Guest Additions CD Image

What about enabling Copy / Paste on Linux Host VirtualBox hosting a Windows Guest OS?

 

 

Enabling Copy / Paste on a Windows Virtual Machine (I wrote about it earlier here), follows the same steps as in this tutorial.
The only difference is instead of running the VBoxLinuxAdditions.sh you have to navigate to the CD from Windows Explorer and run the appropriate .exe file depending on your architecture (X86 or 64 bit), the files to run on the virtual CDROM are one of the 3:

1. VBoxWindowsAdditions-amd64.exe
2. VBoxWindowsAdditions.exe
3. VBoxWindowsAdditions-x86.exe

virtualbox-vm-guest-additions-autoplay-web-on-windows-os

Follow the click through interface and you will have the Copy / Paste between your Linux -> Windows OS working.

Happy Copy / Pasting ! 🙂

Happy New Church Year ! – The Eastern Orthodox Church Year celebrated every 1st of September and some history on the Indiction


September 5th, 2018

Eastern_Orthodox-Church-new-year-indiction

Happy New Year, Happy New Church Year !  🙂

On first of September every year the Holy Eastern Orthodox Church to which I belong is celebrating the beginning of a new Church Calendar feast year.

It is a common practice here in Bulgaria (as we are one of the 14 Eastern Orthodox Churches worldwide) it is a tradition to serve holy liturgies across the country and prayers are lifted to heaven for the well being of the Bulgarian nation and the world.

In the past the beginning of the new year was called also the beginning of the indiction.
In the VI-th century at the time of Emperor Justinian The Great in Byzantine Empire was introduce the Cyclical Calendar based calculation of days (based on indictions ) – this is delivered from latin word indictio (meaning announcement).
Indictions
were celebrated originally on a cyclical periods of 15 years when the а financial review of the properties (possessions) of citizens  that were taxated.

In the Latin Empire the word indictio has been used to mark the exact amount of taxes owed each year and in this is how with the beginning of the new indiction was beginning the new financial year of the empire according to some historians the origin of indictions system has been originating from Egypt.

The official byzantine calculation of indictions begun at the time of Saint Emperor Constantine on 1st of September year 312 A.D.
Historically it is interesting fact both in the Western and in the Eastern Latin empire March was another time marking a New Year …

On 1st of September in the Church it is accepted to read the Bible chapter where Jesus Christ red in the synagogue the prophecy of Isaiah (Is. 61:1-2) for the occurance of the favorable year of God. The Byzantines see in that reading a reference of the Lord for a celebration of a New Year. 

In the Menologion of Basyl II from the 10th century it is said "From that time, he has granted to us the Christians this feast".

Primary_Chronicle_Povesti_Vremeninnih_let-baptizmal-of-Olga

It is interesting fact that in Byzantium this Bible reading was red in the Church by the Patriarch in Hagia Sophia Church Cathedral or another Church where it was common for him to serve Holy Liturgy on that date.

In Russia even though the Baptismal and Christianization of the nation until 15th century the Church New year begun on 1st of March. This is evident from all medieval manuscripts including The most famous and among most ancient Russian manuscript written by the eminent Nestor so called Primary Manuscript (Primary Chronicle) also called Tale of Begone Years.
 

With an Emperor decree of King Peter the I-st (The Great) the new year in Russia is transferred to 1st of January.

Saint_Simeon_Stylites-Stulpnik

Saint Simeon the Stylites

Our Bulgarian Orthodox Church by tradition according to the main Church service instructions book – the Typikon marks on the first day of the new year as a very important "tiny Lord feast" and has tradition to celebrate the memory of saint Simeon the Stylites who spend mostly all his life praying on a Stylite and was a notable ascet of the Orthodox Church.

 

Resize a VirtualBox guest Linux VDI Disk under Linux Host


September 4th, 2018


http://pc-freak.net/images/virtualbox-virtual-machine-guest-Windows-10-Linux-Debian-9-screenshot

I am using Oracle VirtualBox virtual machine to experiment with things before I deploy them on my servers. Recently I installed Debian 9 in a hurry (without much taking attention on the configuration options during VM machine creation) and the negative results of my lack of attention came quickly as my Linux Virtualbox guest OS just ran of space a little time after I have installed a Debian Stretch 9 OS into the virtual machine ..

I didn't realized immediately the "No free disk space" error was there because, after installing a few sets of Debian packages (Exim MTA – exim4-damon-heavy .. related etc.) immediately, shutdown the Virtual Machine running (even of this very moment) on my Thinkpad T420 notebook and went to bed.

This morning I switched on the PC booted my notebook and launched the VM to do another set of experiments inside it, however it seemed it failed to load all services printed in text on Linux boot and the GDM3 Greater never appearead on screen- for those who don't know GDM3 is Linux Graphical environment Authentication / Login program.

gdm3-debian-9-login-errors-low-disk-space-no-free-space-on-disk

I have tried a VirtualBox VM Restart,  hoping that the cause of my problems might be VMachine bug (as I'm running the latest stable version of VirtualBox (Virtualbox 5.2) taken from VBox Linux download page . On Next boot weirdly the OS booted until the GDM greater but inputting the password did not load into GNOME but kept repeatedly asking for password.

After another VM restart (shutdown + re-boot), I could eventually login but I got a Low disk space error like in below screenshot

pc-freak.net/images/debian-linux-9-running-inside-virtual-machine-low-disk-space-stroke-selection

So how to fix the Virtual Debian Install Low Disk Space?

As of today September 4 2018 the way to extend the hard disk, that was prepared originally for the Virtual Machine install you need to give a check inside your Linux home (~/) directory under Virtualbox VMs find the folder that is equivallent to the Virtual Machine (whose Hard Disk Drive) you would like to extend, do a ls command check to identify the exact name of the VDI – [Virtual Desktop Infrastructure] file (in my case, that's is Debian 9.vdi) and use VboxManage modifyhd options command like shown below to resize VM HDD to more gigabytes

1. Resize the Virtualbox VM .VDI file using command line

root@jericho:/home/hipo/VirtualBox VMs/Debian 9# VBoxManage modifyhd 'Debian 9.vdi' –resize 40000
0%…10%…20%…30%…40%…50%…60%…70%…80%…90%…100%

As you see I am resizing my Hard Drive for this Virtual Machine to 40000 = (40 Gigabytes), if you have need / more disk space you might want to set something like 100000 (100GB).

 

2. Resizing .VDI file (Virtual Machine) using VirtualBox GUI

Click on Global Tools button (located leftside upper side on the screen

virtualbox-resize-debian-linux-harddrive-global-tools-screenshot

Drag the bar Size: to the Hard Drive partition size you want it to be …
 

So far so good, now the image file is resized but the GNU / Linux partition is still being small, so we need to also do repartitioning, once booted into the VM in order to stretch the HDD size to 40 Gigas.

Next install and use gparted Linux tool to add the free space to your root partition, use the gparted

Inside the VM instal the tool with:
 

Inside virtualmachine's in gnome-terminal / xterm etc. depending on the graphical environment used do install with apt-get:

 

debian:# apt-get install –yes gparted

 

debian~:# gparted


Notice that gparted has to be ran as a root superuser.

 

Run GParted and create new EXT3 filesystem that is 10GB (the size of the new created partition).

If you have installed Debian to place all partitions under / (root directory /dev/sda1) then the fresh new partition to create should be
/dev/sda3, anyways just look closely in EXT3 and in your case if the partiition is named differently create according to proper partition /dev/ naming.

I'll not run into details on how to create the partition with GParted as the program interface is very self-explanatory, the only thing is to apply the update to create partition and the ext3 filesystem, that's being done
with a green tick:

 

Next step is to check with fdisk whether, we have ext3 properly created  filesystem as we've done already with GPARTED:

Once we have the partition created with EXT3 filesystem, we're ready to move /usr temporary to other folder, I use usually /root for the move but you can create anywhere a new folder for that and move to there.

To move to /root directory run again in terminal:

 

debian:~# mv /usr /root
debian:~# mkdir /usr

 

 

 

Note that during the move operations, your Desktop icons will become without (with broken) pictures and the default Debian background picture is to disappear, that's because the GUI environment will soon realize /usr/ libraries that're periodically reloaded in memory are missing and will be unable to reload them as it does in a cycle.

That should take a few minutes, so grab a coffee or if you're a smoker (hope not as smoking kills 🙂 ), in 5 / 10 minutes time depending on your computer / server configuration, it will be over, so we're ready to create new /usr dir and mount the  new partition:

 

debian:~# mount /dev/sda3 /usr

 

howto-extend-root-filesystem-disk-space-linux-move-usr-folder-to-root-temporary-debian-gnu-linux1

 

Now we check with mount command whether mount is fine:

 

check-if-filesystem-is-properly-mounted-linux-debian-screenshot


Now  /dev/sda3 is mounted under /usr  and we have to move back /root/usr directory content back to the newly mounted /usr so we run command:
 

debian:~#  mv /root/usr/* /usr/*


Finally we need to create proper records for the new partition inside /etc/fstab (fstab –FileSystem Tab file – the file which describes instructs the Linux OS what partition to boot where, what)

 

Recovering from Herniated Cervical disc (neck) and spine disease – keeping in good shape your Back and Neck in easy 4 steps Exercises


August 31st, 2018

recovering-from-herniated-cervical-disc-and-spine-disease-keep-your-back-in-good-shape

If you are a long term computer geek, IT specliast, system administrator a hacker or any type of office worker that spends as a maximum 8 hours / 5 days a week and you do not do some kind of Sports (Running Heavy Lifting, Back or neck Exercises, do Fitness) etc. sooner or later you will start noticing a change in your normal back posture and heavy pain either in back or neck of your body.

The posture you have is in risc and your muscles will slowly start atrophying. It is very likely with years that you will start developing a body muscle strain in the area of neck or back and you will feel tensed / anxious most of the time without a clear reason on what is causing the constant stress you experience.

A heavy and constant anxiety you might develop with the months and years of chair sitting, sedentary lifestyle and staring into the computer screen or spending many hours driving might lead you into sleeping problems a bad blood flow to the brain (if you have neck problems) and other not nice health issues such as ringing in your year / head (tinnitus) and as an impact of all the degeneration of body a change in bone tissues and even brain might happen.
If you're suffering a back spine or neck disease the pain it is about to create daily for you will also impact the level of depression you experience and often it alone could be a cause for depression, because of the violated bodily organs blood flow (especially the brain) …

That's heavy health issues and if you are young you might thing that all this is just an imaginations and it will never happen to you but unfortunately in today's digital age where people tend to spend 10 to 14 hours daily in front of PC notebook / monitor and smartphone or in few hours conversations on the phone, all this with years contributes and sooner or later you will face the terrible reality of suffering from some of the many existing types of Herniated Cervical Disc disease.

So what is Herniated Cervical Disc Disease (shortly explained) ?

Spinal disc herniation, also known as a slipped disc, is a medical condition affecting the spine in which a tear in the outer, fibrous ring of an intervertebral disc allows the soft, central portion to bulge out beyond the damaged outer rings.

The reason to get a herniated cervical disc is usually due to aging a genetical predsposition, constant straining of back due to many hours without physical activity sitting or in bed, traumas, injuries attained during heavy lifing or sports etc.

* What are the symptomps of Herniated Cervical disc ?

The symptoms vary depending of the location of a herniated disc and depends on the soft tissue between the bones that gets involved. Common symptoms however is severe and unrelented neck pain, low back pain, pain in knees or feet, undefined pains in thight etc. … it really depends by the affected region served by affected nerve roots that are irritated or impinged by the herniated material.

Some people suffering from spinal disc herniation is symptoms of numbness, tingling of limbs, overall muscular weakness, paralysis and effection of reflexes, double vision, noise in the head / ears, insomnia and more …

If the herniated disc is in the lumbar region, you will experience scietica (a pain going down the leg from the lower back).

The things becomes even worser and the risk even higher if you're not using a comfortable computer chair at work or home, but you are into the habit to use a laptop or as the girls / women like to do lay on the bed and do stuff on the computer or tablet such as chatting all day long in a social networks such as Facebook or watching movies after a heavy office day.

Just take a look at young people's necks around leaning up and their crooked back posture on the street in bus or metro if you don't believe me and thing and you will be amazed how terrible deformations so many youngsters (teenagers) and even mid age person suffer some early or advanced stage of kyphosis disease (a deformation of the spine / neck) without even realizing it.

Herniated-Lumbar-Disc-pinched-nerve

Suffering Kyphosis (and the usual surrounding Herniated Disc illness) is a terrible thing to experience and this is a silent killer that is plaguing people worse than any other disease, because the disease is developing relatively slow in time it is few that really catch it in early stage and it usually is tracked once you already suffer with some kind of constant pain in neck / back and a Spinal disc herniation or  you had a pinched nerve somewhere in the body because of some kind of constant compression in between spine bones etc.


cervical-herniated-disc-cervical-disease

The majority of spinal disc herniation cases occur in the lumbar region (95% in L4-L5 or L5-S1 – this is a doctors naming for regions where it occurs). The second most common site is the cervical region (C5-C6, C6-C7). The thoracic region accounts for only 0.15% to 4.0% of cases.

For IT specialists Gamers and mostly and people whose profession includes spending their days sitting in front of the computer screen C5-C6 / C6-C7 regions are very common (something that could contribute additionally for the disease is if you suffer some kind of astigmatism eye disease and because of that you keep your neck constantly even more forward to see better what's on the PC screen)

aging-and-body-back-deformation-in-grown-and-aging-people

With age spine and bones are decaying (wearing out) and as a result the spinal cord gets deformated and this is a normal process, we can't change but we can delay it with some daily exerices and work on our bodies so at old age we experience a little better health ..

Well dying is ineveitable anyways 🙂 .. but why not make your quality of life and overall experience in the body a little bit better and do some exercises that will boost your mood to happiness, improve overall blood flow and either help you recover or protect you against a possible herniated disc problems?

I was to a doctor today for a Manual Therapy session, because I happen to suffer from Herniated Cervical Disc ( neck on C6 and C7) which bringing me a lot of unfortable nervous pressure and messing up with my quality of life.
To deal with my problem I went to see one of the best doctors in the field of Physical Medicine and Rehabilitation in Bulgaria and perhaps in the World Assen Aleksiev M. D. Phd in Aleksandrovska University Hospital.

Mr Assen Aleksiev is living legend and one of the bright persons as of time of writting this article he is:

1. Physician – specialist and expert in:

• Physical Medicine and Rehabilitation (with emphasize on orthopaedic and neurological disorders),

• Manual Medicine (Osteopathy, Chiropractics)

• Clinical Electro-diagnostics, Electromyography and Electro-stimulation.

2. Lecturer., 3. Scientist/researcher., 4. Reviewer of medical literature., 5. Author and co-author of medical literature., 6. Manager., 7. National consultant for Physical Medicine and Rehabilitation 2014.
 

After seeing my case and having a number of cases, just like mine and did some Manual therapy fixing my neck back,  limbs etc.

I will share with you the 4 steps, he said I and anyone has to follow in order to prevent himself from Herniated cervical disc degenerative disease to progress  and in worst case to turn me into a mildly disabled.

Even though this exercises were prescribed as a cure and support mechanism for a herniated disc patient that I turned to be, the good doc. shared with me that this set of 4 steps if followed could prevent not only your spine and waist from experiencing the painful discomfort of herniated disc diasese but could generally strengthen the body functioning and protect you from dying from a future strokes (heart attacks) and a number of other cardiological diseases.

So here are the 4 Golden Exercises (STEPS) that, if practiced regularly  will keep you from spinal curvature, will keep your neck and back in a good motion and help you recover from herniated disc diseases.


1. ALWAYS TIGHTEN YOUR STOMACH WHEN YOU SIT DOWN OR STAND UP !!!

– Make the habit to always tighten your stomach when you sit and stand up, this moves the weight of the body on the muscles instead on the bones. If you sit down or stand up without tightened stomach (because of the gravitation the body weight you have increases doubles if you're 70 kilos the body / bones have to bear a weight of 140 kg or so …). Once, again  tightening the stomach makes the weight be received by your muscles and this saves your bones

2. CHANGE THE POSITION OF THE BODY EVERY 15 MINUTES (FOR EXAMPLE YOU'RE SITTING FOR 15 MINUTES ON A CHAIR STAND UP MOVE YOUR SHOULDER FOR 2 / 3 AND SIT BACK) !!!

– Stand up from your chair or whenever you sit and move around your shoulders

3. ON EVERY HOUR PRACTICE SCHOOL (GYMNASTICS) EXERCISES !!!

– 5 Table push ups (if you're in an office for example in a Focus Corner Room) or outside the office building on a bench or something) – compulsory is to make it with a tightened stomach

table-push-ups-Counter-Push-ups-1

Table Push ups (the table angle inclination degree should be at best case about 45 to 60 degree but if it is different angle it is okay as well)
wall-push-up-exercise
if you are in a place where you can't do a table push-up you can do a wall push up

Waist Rotation (Exercise) Put your arms on the waist (in a trinagle form), your legs should be a little bit far from each other in a small triangle like form too and turn your whole body left and then right do it 3 to 5 times each side.

waist-rotation-exercise

Spinal Stretch Exercise (Place fingers at the base of the spine bend forward and backward then left side and right side slowly! do it each direction at least 3 to 5 times (e.g. 5 backwards / forward, 5 left and 5 times right)

spinal-stretch-exercise-forward-and-back

The 8 tact exercise is a complex of 4 exercises each on repeated 2 by the (count number 1, 2, 3, 4, 5, 6, 7, 8)

1, 2, 3, 4 – Put your heads on the level of the chest (bent them so the elbows point right and left then move  them both right and left to the maximum back and stretch cross shaped your both hands

5, 6 – Standing still move Right hand up and move it backwards as much as you can left hand down and move it backwards as much as possible

7,8 – Reverse the hands, Left hand up and move it backwards to maximum and right hand down and move it backwards to maximum

6,8

4. 3 TIMES A DAY (MORNING, MID DAY AND 1 HOUR BEFORE GO TO BED DO A SET OF 15 MINUTES ACTIVE CARDIO TRAINING EXERCISES) !!!

– This could be 15 minutes of running , jumping, push ups, heavy lifting, biking whatever you like to do but let the heart (pulse) rate be heavy loaded …

cardio-Exercises_Guide-you-can-do-at-home


5. Hanging on a lever (recommended not by the good doctor but by Dr. Georgiev e.g. hip0 myself) 🙂

Just find a lever and hang for about 60 seconds every day

Hanging-a-lever-helps-Spine-decompression-relieves-symptoms-of-herniated-disc
 

Following this routine of exercises: will not cost you too much of a time daily

a. It is (3×15 minutes cardio) is 45 minutes of exercise (and maybe another 5 to 15 minutes to go to where you practice it) = 60 minutes (1 hour)

b. Each hour 1 minute of exercises (approximately 14 hours is 14 minutes or at worst case if it takes you two minutes to do the complex of exercises 2×14 = 28 minutes.

c. tightening the stomach once learned is 0 seconds and 0 minutes.

d. hanging (if you choose to do this as well) is 60 seconds (1 minute) – going to the lever is another 3 to 5 minutes at worst case (lets say an overall of 6 minutes)

f. change position of the body every 15 minutes (costs you just up to 5 secs) or (14 hours x (4 x 15) = 60 secs) – that means another 14 minutes.

So the overall time for keeping your spine and neck in a good shape is (28 + 14 + 6 + 0 + 60 minutes) = 108 minutes, that is less than 1 hours and 48 minutes at worst scenario a day.

One helpful program in oder to remind you to not forget your exercises schedule if you choose to give it a try is Workrave see here my previous article on how it can help you Preserve health  from computer Caused Strain Injury (RSI).

But the advantages of following this exercise routine would be your:

1. bettered overall health,
2. less noise in head,

3. better digestion,

4. less strain and pain in neck and back,

5. feeling less anxiety and stress,

6. feeling happier (more Serotonin and Dopamine and other liquids that are boosting mood and helping brian work are pumped up more regularly into the brian),

7. a better concentration / focus on things (something most computer specialists and computer related jobs people miss seriously,

8. a better memory and a better sleep + following the standard school gymnastics exercises is much more safe when compared to Fitness,

9. Less Body Mental Fatigue (as most people with Herniated cervical disc suffer from a body fatigue that often affects the mind and creates a mental fatigue)

10. You don't risk to receive a body or muscle trauma that will last for a life time 🙂

Well, I hope that article helps someone with a herniated disc out or at least serve as a BIG WARNING and push people involved in IT, Digital Marketing, Programming, Logistics and mostly all professionals who require a long hours of hovering in front of the PC to realize the great dangers all this keeps for their health and get more physical activity daily to protect timely from ending up with a spinal digenerative disease and suffer 'till the end of life.

I will be mostly glad to hear if anyone had a personal experience with herniated disc and any spinal / neck degenerative disease and give me more hints on useful things that help in living a life with a herniated disc disease?

Thanks for reading  !

Classical System Administration is dying – you either say hello to DevOps and SRE or move to programming or other business if you can


August 29th, 2018

sysadmin-hell-being-a-sysadmin-is-easy-its-like-riding-a-bike

1. Back in the normal computer old Sys Admin days before the new Age of Computing (the Cloud HELL)

I've been in the system (server) administration business for more than 15 years. We started as kids dreaming about managing big Data Centers having ultimate control over servers data and services and in a sense the beginning of the 2000s looked like the system adminsitration will be among the most promising and profitable professions for the coming 30 years or so.

The amount of servers installed were booming, the Domain Registrantrant Ballon (Dot-Com Bubble) and the appearing need for everyone to have and run a website with the connected hardware and software (OS) needs made the sysadmin of the time like a precious asset for a company and business …

Many companies (small and mid-sized) still did not have a separate role for sys admin, but hired some crazy IT enthusiast that was doing a lot of the sysadm job for them.

It was wild years of freedom for the common IT specialist with a server software install / update / maintenance background.

The complexity level to install configure or tune for performance a (UNIX) like server be it GNU / Linux or FreeBSD or farm of servers was also high and there was little documentation than today and a lot of custom tweaks (scripts) to develop to make things working and system administration job was way more custom than today.
In other words the sys admin was a digital artist just like the UI / Web designer or the common programmer (who was way more advanced and hack, thought oriented) than todays "coders" most of which knows no damn thing but are a great Human Robots serving the functionos of ("Google Search for some ind of Programming language code" then "Copy" and "Paste" into a buggy module / script / application function) and then of course as a result you have a large clumsy (softwares) programs which eat a lot of Server resources (often crash – that's especially true for Java based applications) in the background and get respawned (which does severely load the servers CPUs / Memory) but as the end user is not aware of that it is considered a job finely done.

computers-kills-people-silence-means-security


2. The IT Computing and SysAdmin / Programmer Jobs offered today

In other words nowadays computing is becoming a mess, just like a system is complicating it becomes more prone to failures, the same happens with modern informatics. The chaos of programming languages code and concepts (especially), the abstracts makes a programming code harder to debug than in the past (of course that depends on the programmer too), but as most programmers are totally lame and doesn't understand even basic Hardware / Electronics concepts but are more of a Code Monkeys (yes I can say today's programmers are not really a programmers but a CODE MONKEYS !).

The result for the avarage sys admin is that the developed software are less and less custom but written in a way (to just run it on a server) and usually the sys admin ends up with less and less options for modification or debug problems of the software. As the tendency of installable services / programs (I am talking about the proprietary ones) are becoming more and more monolithic of nature.
As a consequence that starts making the classical system administration as most of todays softwares can be installed even by a highly trained monkeys (no real sysadm needed) and even if you work as a sysadmin it is very likely you are not involved in interesting job but doing more and more routine and burecracy work (which is hell at least for me – as one of my primary motivators to start a career in the IT field and specifically in the field of System Administration that back in the day the system administrator used to be a more important person for a company as a whole company infrastructure depended on the work of that single Super Man that made possible the Internet Accessibility for office users, made possible Linux / Windows servers to operate fine with a bunch of websites and some crazy softwares and platforms, and even took a periodic maintenance of an Office Workers PCs, not to mention the responsibilities to do the frequent data backups, do a support functions (talk heavily on the phone with customers with issues etc.) and help programmers set-up their crazy testing environments (developed project code) on a testing servers etc.

It was the golden age of system administration … and perhaps a golden age for the ones involved in the field of Computing .. really …

3. What if you end up to be a Jobless System Administrator today? What does current sys admin Job Market Place look like?


Have you listened to Venom (black metal band) song – Welcome to Hell?  … its like that ..

Yes, that's the worst nightmare for most of us sys admins , becoming jobless due to company bankruptcy, dismissal or just a desire for a rest for some time from the over active job to talk over the phone with uneasy and angry customers.
Al this put you you in a very harsh situation, because the Classical System Administartor jobs from the past such as building a Strong Company Firewall with IPTABLES or BSD PF is nowdays done by some pre-purchased router such as:

McAffee, Palo Alto, JuniperSRX 2020, Next Generation (firewall as a service such as Cato Networks), Kaspersky, Fortinet, (if you're lucky pfSense), Comodo Internet Security, Zone Alarm (the possible list of sh*t goes on and on …)

In other words businesses nowadays, prefer to buy a ready solution and most of this solutions even though being configurable, often have a weird interfaces and force the user to use a ready set of firewall rules (policies) rather than building ones from scratch … and most of the softwares can be configured by a normal non sysadmin anyways so mostly or soon the sysadm is not needed.

devops-diagram-explained-512px-Devops-toolchain.svg

If in the past you have build things from source or deployed / configured things server by server and each of your servers as a consequence had its kind of own spirit, because of the many custom things placed on it, the current situation with sysadmin job are mass deployments of pre-bundled packages (DevOpsDevelopment Operations – another crazy business non-sense buzzword that describes server scripting automation development) as a DevOps (SysAdmin) which is some kind of Hybdir between a programmer / scripter / db developer / and scripter you have to be eloquent or at least have some basic knowledge in mass deploy tools such as Docker, Ansible, Chef, Puppet, TeamCity, Bamboo, Fabric, Etc.
and to add even more hell to the hell, in most System Administration jobs you perhaps won't manage your own company data even but you will have to deal with third party vendors such as AWS Amazon or store the company important data in some external Cloud Storage service (except if you don't have the option to choose for a custom Own Cloud solution)

But often this is not enough you have to be more or less aware or have some experience with some SRE (Site Reliability Engineering)

But wait, that's not enough you need to be also a good Team Player communicate to a good number of often lame burecrats / lame progammers / a manager over your head that usually does not know shit about technology / a project manager / some Database guys that oten have a very questionable knowledge in Database programming maintenance .. etc. …  and the worst (in my humbe opinion) is that you have to spend 2, 3 as a mimumum daily in a non-sense meetings over proprietary non-free software program such as Skype For Business or Web Room meeting online such as WebEx with people that have little to know idea about technology or are presenting professionals but have a very questionable amount of knowledge in their field …

To summarize modern SysAdmin jobs, just like all other jobs are slavery but with the difference that in most common daily jobs most people have more freedom and are less dependent for their daily work, than you end up as a New Age of Computing Sys Admin.

system-administrator-stress-October-Poll-Sysadmin-Results-stress

Oh yeah and lets not forget the high amounts of STRESS you get daily as a sysadmin that for some is almost 24/7 especially for people who manage a large networks or server infrastructures. Suppose you migrate a Web services, database service, mail server, DNS record etc. and you make a minor mistake so the users can't access the service, guess who will be fired first ?! YOU !!! Even if you don't get hired, you'll be murmored and send for some kind of meaningless training just because you did a mistake (which is very normal, as every human daily days tons of mistakes) …

Another thing is if you're truely dedicated to system administration profession and you spend hours reading and learning new technologies (which in the field of system administration is inevitable) or just doing work from home as a freelancer to get some extra bucks and you don't have to actively sport (Running, Biking, Fitness, Mountaun Riding, whatver …), your Spinal problems and Herniated Discs (Neck or Waist) is to soon knock your door
and stay with you until your death bed.

 

But that's not all of the hurdles, many of the System Administrator like jobs of today require you to have an overview knowledge on Virtualization technologies such as VMWare ESX, VServer … and have a good idea about VPS management and even some employeers require a knowledge in Astrerisk IP PBX (Open Source Communiation Software) or other IP Telelphony software strangie …

Dear sysadmin collegues, my opinion is this kind of requirements are a little bit higher and almost impossible to match (or there are none to any living flesh) that attains all this knowledge or they will ever be.

… But even if you get employeed (and you tricked the HR interviee that you own the SuperMan + Batman + Robocop + You name your favourite movie superhero superpowers and went through the other interview (hell) circles) … finally you get hired and you end up often part of projects that are already seriously messed up from the start or developed in a way that even if succeed in a short term, guarantees a long term failure.

Oh the hirement process is also a lot of enjoyment for the burecracy freak, you have to fill in a number of documents, describing tons of information, provide tons of documents, certifications, talk a number of times on the phones with inadequate Human Resource representative (usually highly brainwashed ppl) "specialist" that knows shit about technology … Then you have to go to a few more selections, interviews further with a technical guy, fill in tests online (maybe not always) and finally talk to a company manager.

All above screening and selection I'm desribing of-course is featuring large corporations (which are among the little) that offers some decent sallaries like 1500 – 1800 EUR (for Eastern Europe) or 3000 – 3500 for rest of Western Europe (if you're a lucky American citizen you might earn up to 10 000 – 11 000 $).
The advantages of the large corporation besides the so-so sallary is the sense of security (that you want be jobless just next year or two from your day 1 in the company).

You can always become a sysadmin in a start-up company but finding such is also nowadays a real pain in the ass and even if you have a 12000+ unique a day visits site such as mine and you offer your sys admin skills for really cheap , you still will have troubles in finding clients / employeer for whom you can practice your skills and make a living as a SysAdmin.

That's pretty weird for me especially with the fact that everyone is tubing that more and more IT specialists are required ..

Anyways assuming you have the "luck" to get hired in a large corporation such as IBM you will have to do a very tedious job, such as either Backup with (IBM Data Protect), Veritas Backup, Barracuda Backup, HP Data Protector or similar software, only do build or deploy new servers, web services, databases or whatever else. E.g. your type of work is likely to be monotonоus and boring and will offer you not much than learning a little bit more about the technology you're already acquainted to ..

Moreover, because in modern IT, human freedom is not really respected … you either comply to the company brainwashing strategies a bulk shit procedures or you get fired, you either become a small wheel in the failing machine (here i mean most large companies you might end up hired nowdays reached its peak state are into a decline) and a logical result is living in constant fear that they might fire you end you might end up jobless or you stand up for what you're in the company and be careless about political correctnes and you quickly get inconvenient, politically incorrect (oh yes I forgot to mention this other craziness if you happen to be employeed you have to be politically correct) and do periodically a stupid exhausting Trainings (I prefer to call them a brainwashing session as most of the trainings are not teaching you anything but just wash your head to comply to shit). But if that Hell is not enough in the large corporation in order to look "normal" you have to partcipate in the Non-Sense Teambuildings, with team mates you have little to know affection (with the very same people you spend 5 days a week, now you have spend 1 /2 more day. every month or so …

long-term-ago-people-who-sacrifice-their-time-sleep-family-food-laughter-were-called-saints-now-they-are-called-it-professionals

So welcome to modern HELL OF system administration, or better to say welcome to the Cult of the large corporation businesses.

4. What are your options if you end up as a poor old school sys admin on the job market?

If you have a long history as a sys admin and computers become too boring for you like my case, you can always think about migrating to a Management position in the field of IT (this in most cases means doing nothing all day long pretending that you understand management and talking shit (laughing in a group), being present in a crazy management meeting whose essense is a shit talk all day long … with a bunch of people who facebook / youtube all day long talk about Latest Cars models and how they wish to have a half million car, watch and talk about fuzzy hand clocks, cheeks, plan their next vacation or where to have the lunch and housing (apartments) all day long (in some more extravagant cases you have some guys being wacky talking about drugs, sex and  rock-and-roll.)
but the unpleasent surprise here is even as a Manager you will probably have to start working for a corporation and have the same depressing atmosphere of people standing in front of their computers (tailor like) all their long with the only difference you will have to speak more with a number of computer addict zoombies (left without much options) that are doing some monkey programming / coding or Services job day after …

Other option you have is to move out of the virtual business at all and get into a real works industry such as getting a Construction job (but believe me such transitions, though I heard of are too painful) and sooner or later you will get back to computing virtual business ..

I have a friend Jose Mathew, whose exit poll from the IT business was to graduate a 2 years post-university course to become a professional Chef (cook) in restaurant but after already few years employeed as a Cook, he is again considering getting back into the IT and paradoxically he wants to enter the niche of Network Administrator (which I forget to mention earlier in that article).

The Network Administrators are among lucky System Administartors job profiles because there job is depending nowadays mostly on their CCNA / CCNP certificate, there experience with network routers such as Juniper, LinkSys, Cisco, Avaya etc.  But the big problem with being one of the guys is that the employment jobs offered are much less than the general Senior or Junior System Administrator (that is more free software Linux based).

The most luckly ones are the Windows System Administrators as the amount of such that are looked up on the market at the moment of writting this article is relatively high. The type of job for Win Sys Admin offered on the market as long as I researched is for Windows Sys Admins that have a good amount of experience / knowledge (with Active Directory) domain controller.

There might be some enjoyment for the Win SysAdmin if you have to develop your own PowerShell scripts or do some kind of automations on a domain controller level and from that perspective this job positions are attractive, but unfortunately that comes at the price for being a totally Microsoft software dependent (junkie).
But in overall it is much easier for the ordinary Win Sys Admin than the Unix one because of the reason Windows Servers and related scripting automation solutions is generally much easier to learn and many of the things you have to make up yourself on a common *NIX OS are already available in Windows in the form of some proprietary extra software you have to buy …
However for people as me who are involved in the UNIX world for the last 15 years, it want be easy to migrate to Windows System Administartor.

In my previous employment Job in Hewlett Packard (and later DXC) I have to do a lot of Windows System Administration jobs and I have to says, that was too easy in general but the downside of deploying some third party software on Windows in case of failure is the debugging on Windows is generally harder task than on Linux / BSD..

Another option if you want to move from the field of System Administarton is to start your own company in either Sys Admin or Programming field or Website building, Website hosting.
That's easy especially if you have a good amount of experience but the problem with this is you need a partner and often finding a partner is a tedious job …
Plus most of the clients you can get for your business are already clients of the Large Sharks corporations and at best you or your company might have to work as a contractor for the uncle SAM corporations ..

Of course as a sysadmin you can always repair computers and could try to start a business of computer (OS) repair niche, but as the competition in the field is enormous and you will have to work like crazy to be able to make a decent living, plus it is very likely that you bankrupt, because of lack of enough clients in need to fix their OS (as most people nowadays have learned on how to install Windows and basic surrounding softwares) …

 



system-administration-is-dying-grave-RIP-sysadmins

 


If you have land like my parents you can try to make a living by growing vegetables like Bio potatoes, cucumbers, tomatoes, cabbage, onions, garlic and other fruits such as Apples, Pears, Walnuts, Peaches etc.
The bio-fruits growing business though profitable in western societies is way from profitable in Eastern world so if you happen to be in some eastern country and you want to make good moving to the fruit growing / selling business might not make you rich but at least you will have benefits for your health because of the village / land work + you will have a little bit more independence and your mind will be much clearer. If you decide to try a physical work like this, your concentration level will improve as most IT industry people because of the long hours of computer madness jobs slowly start totally loose focus and often the stress of the Computer works impare memory ..

 

 

Another option for exit from System Administration industry if you have some little marketing experience or background is to move to become a Marketing or E-Marketing SEO specialist, that's not a bad option but the problem is still you will bundled in a permament marriage with the computer and the sallary you will get would most likely no different from the one you will get as a system administrator.
So just like any other Computer related job in order to keep in shape you either have to go Fitness 2 / 3 times a week or actively sport something, otherwise you might experience a growing decline in health over time (just like you already might have in sys admin field).

To sum up being a sysadmin is very enjoyable fun and bright profession, the only small problem is most true dedicated system administrators are know tend to suffer constant anxiety, hyper activity, have physical health issues, suffer forms of depressions or have mental issues (perhaps because of the inhuman amount of information they have to process daily and the large amounts of hard alcohol vodka, beer etc. 🙂 consumed as a mean of anti-depressant) …
But it seems other IT specialists I know such as programmers tend to often suffer similar problems. Besides that many of the people involved in sysadmin business or IT have troubles finding decent woman to marry, as they tend to become more or less anti-social (or gradually loose their ability for proper interactivion with human) because of the fact most of their life is being led in the virtual reality online.

But lets be optimistic, perhaps there are many sysadmins who have the luck to have started a normal life in a normal company and managed their life well with family and kids it is just I haven't met them yet 🙂

I know this post was quite a lot of rant and I would like to excuse anyone who was bored to read all this mess, but I felt obliged to share about this problem as the things are rushing through my mind for over a two years now and we had quite a discussions with friends / collegues on the realization that the system administration job is loosing its attractivity and that the new age of (cloud) computing is pushing computer science to move towards a bad and dark path which makes the individual both employee and user more dependant and less free  …

How to install BlueJeans Video calls, sharing, Conference software on Debian / Ubuntu Linux – Convert RPM to DEB package with alien howto


August 28th, 2018

bluejeans-linux-logo

As I'm currently looking for ways to maximize my incomes without taking participation in 5 days week 8 hours schedule in a Big Corporation office job (which prooved for me to be a terrible slavery) I decided to give Free Lancing a try once again. 
Historically I have registrations in some of the most popular Free Lancing services Web platforms such as freelancer.com and upwork.com.
But none of them really was easy enough to handle as applying and winning a project there is usually a lot of headbanging into the walls and the platforms are full of clients that are looking for free lancers for short-term projects the work selection there required too much work, often projects offered there are seriously under-paid and its really hard to negotiate with many of the clients as they're unprofessional in the fields they're working (don't get me wrong I'm not saying many people are not very successful with this platforms, and that the platforms are not providing work for me I only say it is not really something to my liking …

In the mean time if you happen to read this article and looking for a High Quality Empoyee Cheap System Administrator or automation developmer, an IT counseling FreeLancer or a Ultra cheap WebHosting service in the European Union, I'll be very happy if you become my client.

Anyways … further on I decided to further experiment a little bit with other Free Lancing platforms (suggested by a friend Mitko Ivanov who helped me a lot with things and is continuing to help me over the last year ).

So following his kind suggestion I already tried one of the popular FreeLancing freeeup.com which is looking only for a best specialists into the fields of Marketing, Development, System Administration etc. but even though I tried hard with them the guys decided I am not matching there criteria for a the best 1% of all the people in the field of IT so my application for the platform was rejected twice over the last 1 month and a half.

Another similar new platform for free lancing that looks promising that I've learned about is toptal.com (there site Slogan is Hire FreeLance Talent from the Top 3%) so I went there and registered.

I had hit a road block there too as it seems, there website registration form was not tested enough with non-Windows operating systems with Mozilla Firefox and as it happens that I am using Debian GNU / Linux for my Desktop their drop-down menus was not working, just like some of the form on their website regular expression checks failed.

I've contacted the guys to inform them about their problems (and they kindly advised) I just give a try a registration with different browser (i.e. Google Chrome) which I immediately did and registratoin there was finally a success.
I have to say the new user application form registration of toptal also annoyed me with the stupid requirement to provide a picture in 1000px x 1000px but as this freelancing platform is still new and has way to go until it is established name in the field of freelancing such as upwork.com and I warmly excuse them.

Once registerered for them the user has to schedule an entry interview just like it goes with a standard company interview with a kind of Human Resources (HR) specialist and I guess some technical guys in order to evaluate on your value (Ha-Ha, someone else to determine your value is already crazy but all crazy employees do it still, of course I don't care as I well know that my value is much more than what they put on me).
The online interview once scheduled has to be done in a Web Meeting (Online Rooms) Platform called BlueJeans similar to Cisco WebEx (that is today heavily used in Corporate world in companies such as Hewlett Packard where we used it heavily, IBM, Concentrix etc.) and others Zoom, JoinMe GotoMeeting, HighFive.

As you could guess BlueJeans (which is by the way a Cloud based meeting software – yackes !) is planned to work mainly on Windows and Mac OS Operating Systems and even though there is a BlueJeans Linux version the provided binary is only for RedHat based linuxes in the RPM binary package format, so in order for me to participate in the scheduled meeting, I either had to port the package and install it on my Debian (what triggeted me to write this article or) use a Virtual Machine such as VirtualBox or VMWare running some kind of Windows OS such as Windows 8 / 10 etc.

Even though I have a Windows 10 OS testbed in a Virtualbox container, I preferred to not use it for BlueJeans and do it the hard way and install BlueJeans on my Debian 9.5 Stretch Linux.

That appeared to be a relatively easy process, so below is how I did it:

1. Download alien convertion (tool) that allows you to convert RPM -> deb, Slackware -> Deb and Linux Standard Base (LDB) packages to deb package format

 

noah:~# apt-get install –yes alien

 

2. Download latest BlueJeans version from BlueJeans website
 

As of time of writting this article the download link for bluejeans online conferencing software is here

 

noah:~# wget https://swdl.bluejeans.com/desktop/linux/1.36/1.36.9/bluejeans-1.36.9.x86_64.rpm

 

3. Convert bluejeans rpm package with alien

 

noah:~# alien –to-deb bluejeans-*.rpm
 

 

 

Warning: Skipping conversion of scripts in package bluejeans: postinst postrm preinst prerm
Warning: Use the –scripts parameter to include the scripts.
bluejeans_1.36.9-2_amd64.deb generated
root@jericho:/home/hipo/Свалени# dpkg -i bluejeans_*.deb
Selecting previously unselected package bluejeans.
(Reading database … 516203 files and directories currently installed.)
Preparing to unpack bluejeans_1.36.9-2_amd64.deb …
Unpacking bluejeans (1.36.9-2) …
Setting up bluejeans (1.36.9-2) …

 


4. Install the deb package as usual with dpkg tool

 

noah: ~# dpkg -i bluejeans_*.deb

 

By default BlueJeans were installed under directory /opt/bluejeans

 

 

noah:~# ls -al /opt/bluejeans/bluejeans-bin
-rwxr-xr-x 1 root root 72423392 Jun 14 02:31 /opt/bluejeans/bluejeans-bin*

 

5. Fix missing library links if such are present in order to make BlueJeans workable

Historically I have dealt with many Linux programs that are provided only in RPM package format and I knew that often once an RPM is converted to DEB with alien due to the package dependency differences on Redhats (CentOS / Fedora etc.) there are problems with missing libraries.

This time this was the case as well, so as usual right after install I did a check up with ldd (print shared object dependencies Linux command) to find out about missing libraries and one library appeared missing.

 

noah:~# ldd /opt/bluejeans/bluejeans-bin
    linux-vdso.so.1 (0x00007fffa2182000)
    librt.so.1 => /lib/x86_64-linux-gnu/librt.so.1 (0x00007fae95f5e000)
    libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007fae95d5a000)
    libgtk-x11-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libgtk-x11-2.0.so.0 (0x00007fae95718000)
    libgdk-x11-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libgdk-x11-2.0.so.0 (0x00007fae95463000)
    libatk-1.0.so.0 => /usr/lib/x86_64-linux-gnu/libatk-1.0.so.0 (0x00007fae9523d000)
    libpangocairo-1.0.so.0 => /usr/lib/x86_64-linux-gnu/libpangocairo-1.0.so.0 (0x00007fae95030000)
    libgdk_pixbuf-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libgdk_pixbuf-2.0.so.0 (0x00007fae94e0c000)
    libcairo.so.2 => /usr/lib/x86_64-linux-gnu/libcairo.so.2 (0x00007fae94aef000)
    libpango-1.0.so.0 => /usr/lib/x86_64-linux-gnu/libpango-1.0.so.0 (0x00007fae948aa000)
    libfreetype.so.6 => /usr/lib/x86_64-linux-gnu/libfreetype.so.6 (0x00007fae945f5000)
    libfontconfig.so.1 => /usr/lib/x86_64-linux-gnu/libfontconfig.so.1 (0x00007fae943b2000)
    libgobject-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0 (0x00007fae9415e000)
    libglib-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0 (0x00007fae93e48000)
    libX11.so.6 => /usr/lib/x86_64-linux-gnu/libX11.so.6 (0x00007fae93b0a000)
    libXi.so.6 => /usr/lib/x86_64-linux-gnu/libXi.so.6 (0x00007fae938fa000)
    libnss3.so => /usr/lib/x86_64-linux-gnu/libnss3.so (0x00007fae935b1000)
    libnssutil3.so => /usr/lib/x86_64-linux-gnu/libnssutil3.so (0x00007fae93381000)
    libsmime3.so => /usr/lib/x86_64-linux-gnu/libsmime3.so (0x00007fae93154000)
    libplc4.so => /usr/lib/x86_64-linux-gnu/libplc4.so (0x00007fae92f4f000)
    libnspr4.so => /usr/lib/x86_64-linux-gnu/libnspr4.so (0x00007fae92d10000)
    libgconf-2.so.4 => /usr/lib/x86_64-linux-gnu/libgconf-2.so.4 (0x00007fae92adf000)
    libexpat.so.1 => /lib/x86_64-linux-gnu/libexpat.so.1 (0x00007fae928ad000)
    libXext.so.6 => /usr/lib/x86_64-linux-gnu/libXext.so.6 (0x00007fae9269b000)
    libXfixes.so.3 => /usr/lib/x86_64-linux-gnu/libXfixes.so.3 (0x00007fae92495000)
    libXrender.so.1 => /usr/lib/x86_64-linux-gnu/libXrender.so.1 (0x00007fae9228b000)
    libXcomposite.so.1 => /usr/lib/x86_64-linux-gnu/libXcomposite.so.1 (0x00007fae92088000)
    libasound.so.2 => /usr/lib/x86_64-linux-gnu/libasound.so.2 (0x00007fae91d8a000)
    libXdamage.so.1 => /usr/lib/x86_64-linux-gnu/libXdamage.so.1 (0x00007fae91b87000)
    libXtst.so.6 => /usr/lib/x86_64-linux-gnu/libXtst.so.6 (0x00007fae91981000)
    libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007fae91763000)
    libcap.so.2 => /lib/x86_64-linux-gnu/libcap.so.2 (0x00007fae9155d000)
    libudev.so.0 => not found
    libdbus-1.so.3 => /lib/x86_64-linux-gnu/libdbus-1.so.3 (0x00007fae9130c000)
    libnotify.so.4 => /usr/lib/x86_64-linux-gnu/libnotify.so.4 (0x00007fae91104000)
    libstdc++.so.6 => /usr/lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007fae90d85000)
    libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007fae909f2000)
    libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007fae907db000)
    libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007fae90421000)
    /lib64/ld-linux-x86-64.so.2 (0x00007fae96166000)
    libgmodule-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libgmodule-2.0.so.0 (0x00007fae9021d000)
    libgio-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0 (0x00007fae8fe7f000)
    libpangoft2-1.0.so.0 => /usr/lib/x86_64-linux-gnu/libpangoft2-1.0.so.0 (0x00007fae8fc6a000)
    libfribidi.so.0 => /usr/lib/x86_64-linux-gnu/libfribidi.so.0 (0x00007fae8fa53000)
    libXinerama.so.1 => /usr/lib/x86_64-linux-gnu/libXinerama.so.1 (0x00007fae8f850000)
    libXrandr.so.2 => /usr/lib/x86_64-linux-gnu/libXrandr.so.2 (0x00007fae8f645000)
    libXcursor.so.1 => /usr/lib/x86_64-linux-gnu/libXcursor.so.1 (0x00007fae8f43b000)
    libpng16.so.16 => /usr/lib/x86_64-linux-gnu/libpng16.so.16 (0x00007fae8f208000)
    libz.so.1 => /lib/x86_64-linux-gnu/libz.so.1 (0x00007fae8efea000)
    libpixman-1.so.0 => /usr/lib/x86_64-linux-gnu/libpixman-1.so.0 (0x00007fae8ed44000)
    libxcb-shm.so.0 => /usr/lib/x86_64-linux-gnu/libxcb-shm.so.0 (0x00007fae8eb41000)
    libxcb.so.1 => /usr/lib/x86_64-linux-gnu/libxcb.so.1 (0x00007fae8e919000)
    libxcb-render.so.0 => /usr/lib/x86_64-linux-gnu/libxcb-render.so.0 (0x00007fae8e70b000)
    libthai.so.0 => /usr/lib/x86_64-linux-gnu/libthai.so.0 (0x00007fae8e501000)
    libuuid.so.1 => /lib/x86_64-linux-gnu/libuuid.so.1 (0x00007fae8e2fa000)
    libffi.so.6 => /usr/lib/x86_64-linux-gnu/libffi.so.6 (0x00007fae8e0f1000)
    libpcre.so.3 => /lib/x86_64-linux-gnu/libpcre.so.3 (0x00007fae8de7f000)
    libplds4.so => /usr/lib/x86_64-linux-gnu/libplds4.so (0x00007fae8dc7b000)
    libgthread-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libgthread-2.0.so.0 (0x00007fae8da79000)
    libdbus-glib-1.so.2 => /usr/lib/x86_64-linux-gnu/libdbus-glib-1.so.2 (0x00007fae8d851000)
    libsystemd.so.0 => /lib/x86_64-linux-gnu/libsystemd.so.0 (0x00007fae8d5c9000)
    libselinux.so.1 => /lib/x86_64-linux-gnu/libselinux.so.1 (0x00007fae8d3a1000)
    libresolv.so.2 => /lib/x86_64-linux-gnu/libresolv.so.2 (0x00007fae8d18a000)
    libmount.so.1 => /lib/x86_64-linux-gnu/libmount.so.1 (0x00007fae8cf31000)
    libharfbuzz.so.0 => /usr/lib/x86_64-linux-gnu/libharfbuzz.so.0 (0x00007fae8cc81000)
    libXau.so.6 => /usr/lib/x86_64-linux-gnu/libXau.so.6 (0x00007fae8ca7d000)
    libXdmcp.so.6 => /usr/lib/x86_64-linux-gnu/libXdmcp.so.6 (0x00007fae8c877000)
    libdatrie.so.1 => /usr/lib/x86_64-linux-gnu/libdatrie.so.1 (0x00007fae8c66f000)
    liblzma.so.5 => /lib/x86_64-linux-gnu/liblzma.so.5 (0x00007fae8c449000)
    liblz4.so.1 => /usr/lib/x86_64-linux-gnu/liblz4.so.1 (0x00007fae8c22c000)
    libgcrypt.so.20 => /lib/x86_64-linux-gnu/libgcrypt.so.20 (0x00007fae8bf10000)
    libblkid.so.1 => /lib/x86_64-linux-gnu/libblkid.so.1 (0x00007fae8bcc1000)
    libgraphite2.so.3 => /usr/lib/x86_64-linux-gnu/libgraphite2.so.3 (0x00007fae8ba94000)
    libbsd.so.0 => /lib/x86_64-linux-gnu/libbsd.so.0 (0x00007fae8b87d000)
    libgpg-error.so.0 => /lib/x86_64-linux-gnu/libgpg-error.so.0 (0x00007fae8b65d000)

 


As I am on my notebook with Debian 9 and on Debian / Ubuntus and other Linuxes udevd daemon and connected libraries are long time existing, it was obvious the problems to dependencies are because of missing library links (or library version inconsistencies).

To find out what kind of libudev.so* are present I used slocate package (locate) command.

 

noah:~# locate libudev.so
/lib/i386-linux-gnu/libudev.so.1
/lib/i386-linux-gnu/libudev.so.1.6.10
/lib/x86_64-linux-gnu/libudev.so
/lib/x86_64-linux-gnu/libudev.so.1
/lib/x86_64-linux-gnu/libudev.so.1.6.10

 

Obviously the missing library libudev.so.0 was present under a different name so I give a try to just create a new symbolic link from libudev.so.1 to libudev.so.0 hoping that the libudev library version Blue Jeans was compiled against did not have a missing binary objects from the ones installed on my OS.

 

noah:~# ln -sf /lib/x86_64-linux-gnu/libudev.so.1 /lib/x86_64-linux-gnu/libudev.so.0

 

noah:~# ldd /opt/bluejeans/bluejeans-bin |grep -i 'not found'

 

Above command did not return any missing libraries, so I went further and executed it.

6. Go start BlueJeans and register a user or use the anonymous login to be ready for the scheduled online meting

… And, Guess, what it works! 🙂
 

 

noah:~# /opt/bluejeans/bluejeans-bin

 

To make it easy to remember to later start the binary under a familiar name, I've also created a link into

 

noah:~# ln -sf /opt/bluejeans/bluejeans-bin /usr/bin/bluejeans
 

 

 

noah:~#  sudo su – hipo
hipo@noah:~$ /usr/bin/bluejeans

 

bluejeans-video-conferencing-online-sharing-meeting-software-running-on-debian-gnu-linux-screenshot
 

Nginx increase security by putting websites into Linux jails howto


August 27th, 2018

linux-jail-nginx-webserver-increase-security-by-putting-it-and-its-data-into-jail-environment

If you're sysadmining a large numbers of shared hosted websites which use Nginx Webserver to interpret PHP scripts and serve HTML, Javascript, CSS … whatever data.

You realize the high amount of risk that comes with a possible successful security breach / hack into a server by a malicious cracker. Compromising Nginx Webserver by an intruder automatically would mean that not only all users web data will get compromised, but the attacker would get an immediate access to other data such as Email or SQL (if the server is running multiple services).

Nowadays it is not so common thing to have a multiple shared websites on the same server together with other services, but historically there are many legacy servers / webservers left which host some 50 or 100+ websites.

Of course the best thing to do is to isolate each and every website into a separate Virtual Container however as this is a lot of work and small and mid-sized companies refuse to spend money on mostly anything this might be not an option for you.

Considering that this might be your case and you're running Nginx either as a Load Balancing, Reverse Proxy server etc. , even though Nginx is considered to be among the most secure webservers out there, there is absolutely no gurantee it would not get hacked and the server wouldn't get rooted by a script kiddie freak that just got in darknet some 0day exploit.

To minimize the impact of a possible Webserver hack it is a good idea to place all websites into Linux Jails.

linux-jail-simple-explained-diagram-chroot-jail

For those who hear about Linux Jail for a first time,
chroot() jail is a way to isolate a process / processes and its forked children from the rest of the *nix system. It should / could be used only for UNIX processes that aren't running as root (administrator user), because of the fact the superuser could break out (escape) the jail pretty easily.

Jailing processes is a concept that is pretty old that was first time introduced in UNIX version 7 back in the distant year 1979, and it was first implemented into BSD Operating System ver. 4.2 by Bill Joy (a notorious computer scientist and co-founder of Sun Microsystems). Its original use for the creation of so called HoneyPot – a computer security mechanism set to detect, deflect, or, in some manner, counteract attempts at unauthorized use of information systems that appears completely legimit service or part of website whose only goal is to track, isolate, and monitor intruders, a very similar to police string operations (baiting) of the suspect. It is pretty much like а bait set to collect the fish (which in this  case is the possible cracker).

linux-chroot-jail-environment-explained-jailing-hackers-and-intruders-unix

BSD Jails nowadays became very popular as iPhones environment where applications are deployed are inside a customly created chroot jail, the principle is exactly the same as in Linux.

But anyways enough talk, let's create a new jail and deploy set of system binaries for our Nginx installation, here is the things you will need:

1. You need to have set a directory where a copy of /bin/ls /bin/bash /bin/,  /bin/cat … /usr/bin binaries /lib and other base system Linux system binaries copy will reside.

 

server:~# mkdir -p /usr/local/chroot/nginx

 


2. You need to create the isolated environment backbone structure /etc/ , /dev, /var/, /usr/, /lib64/ (in case if deploying on 64 bit architecture Operating System).

 

server:~# export DIR_N=/usr/local/chroot/nginx;
server:~# mkdir -p $DIR_N/etc
server:~# mkdir -p $DIR_N/dev
server:~# mkdir -p $DIR_N/var
server:~# mkdir -p $DIR_N/usr
server:~# mkdir -p $DIR_N/usr/local/nginx
server:~# mkdir -p $DIR_N/tmp
server:~# chmod 1777 $DIR_N/tmp
server:~# mkdir -p $DIR_N/var/tmp
server:~# chmod 1777 $DIR_N/var/tmp
server:~# mkdir -p $DIR_N/lib64
server:~# mkdir -p $DIR_N/usr/local/

 

3. Create required device files for the new chroot environment

 

server:~# /bin/mknod -m 0666 $D/dev/null c 1 3
server:~# /bin/mknod -m 0666 $D/dev/random c 1 8
server:~# /bin/mknod -m 0444 $D/dev/urandom c 1 9

 

mknod COMMAND is used instead of the usual /bin/touch command to create block or character special files.

Once create the permissions of /usr/local/chroot/nginx/{dev/null, dev/random, dev/urandom} have to be look like so:

 

server:~# ls -l /usr/local/chroot/nginx/dev/{null,random,urandom}
crw-rw-rw- 1 root root 1, 3 Aug 17 09:13 /dev/null
crw-rw-rw- 1 root root 1, 8 Aug 17 09:13 /dev/random
crw-rw-rw- 1 root root 1, 9 Aug 17 09:13 /dev/urandom

 

4. Install nginx files into the chroot directory (copy all files of current nginx installation into the jail)
 

If your NGINX webserver installation was installed from source to keep it latest
and is installed in lets say, directory location /usr/local/nginx you have to copy /usr/local/nginx to /usr/local/chroot/nginx/usr/local/nginx, i.e:

 

server:~# /bin/cp -varf /usr/local/nginx/* /usr/local/chroot/nginx/usr/local/nginx

 


5. Copy necessery Linux system libraries to newly created jail
 

NGINX webserver is compiled to depend on various libraries from Linux system root e.g. /lib/* and /lib64/* therefore in order to the server work inside the chroot-ed environment you need to transfer this libraries to the jail folder /usr/local/chroot/nginx

If you are curious to find out which libraries exactly is nginx binary dependent on run:

server:~# ldd /usr/local/nginx/usr/local/nginx/sbin/nginx

        linux-vdso.so.1 (0x00007ffe3e952000)
        libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007f2b4762c000)
        libcrypt.so.1 => /lib/x86_64-linux-gnu/libcrypt.so.1 (0x00007f2b473f4000)
        libpcre.so.3 => /lib/x86_64-linux-gnu/libpcre.so.3 (0x00007f2b47181000)
        libcrypto.so.0.9.8 => /usr/local/lib/libcrypto.so.0.9.8 (0x00007f2b46ddf000)
        libz.so.1 => /lib/x86_64-linux-gnu/libz.so.1 (0x00007f2b46bc5000)
        libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f2b46826000)
        /lib64/ld-linux-x86-64.so.2 (0x00007f2b47849000)
        libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007f2b46622000)


The best way is to copy only the libraries in the list from ldd command for best security, like so:

 

server: ~# cp -rpf /lib/x86_64-linux-gnu/libthread.so.0 /usr/local/chroot/nginx/lib/*
server: ~# cp -rpf library chroot_location

etc.

 

However if you're in a hurry (not a recommended practice) and you don't care for maximum security anyways (you don't worry the jail could be exploited from some of the many lib files not used by nginx and you don't  about HDD space), you can also copy whole /lib into the jail, like so:

 

server: ~# cp -rpf /lib/ /usr/local/chroot/nginx/usr/local/nginx/lib

 

NOTE! Once again copy whole /lib directory is a very bad practice but for a time pushing activities sometimes you can do it …


6. Copy /etc/ some base files and ld.so.conf.d , prelink.conf.d directories to jail environment
 

 

server:~# cp -rfv /etc/{group,prelink.cache,services,adjtime,shells,gshadow,shadow,hosts.deny,localtime,nsswitch.conf,nscd.conf,prelink.conf,protocols,hosts,passwd,ld.so.cache,ld.so.conf,resolv.conf,host.conf}  \
/usr/local/chroot/nginx/usr/local/nginx/etc

 

server:~# cp -avr /etc/{ld.so.conf.d,prelink.conf.d} /usr/local/chroot/nginx/nginx/etc


7. Copy HTML, CSS, Javascript websites data from the root directory to the chrooted nginx environment

 

server:~# nice -n 10 cp -rpf /usr/local/websites/ /usr/local/chroot/nginx/usr/local/


This could be really long if the websites are multiple gigabytes and million of files, but anyways the nice command should reduce a little bit the load on the server it is best practice to set some kind of temporary server maintenance page to show on the websites index in order to prevent the accessing server clients to not have interrupts (that's especially the case on older 7200 / 7400 RPM non-SSD HDDs.)
 

 

8. Stop old Nginx server outside of Chroot environment and start the new one inside the jail


a) Stop old nginx server

Either stop the old nginx using it start / stop / restart script inside /etc/init.d/nginx (if you have such installed) or directly kill the running webserver with:

 

server:~# killall -9 nginx

 

b) Test the chrooted nginx installation is correct and ready to run inside the chroot environment

 

server:~# /usr/sbin/chroot /usr/local/chroot/nginx /usr/local/nginx/nginx/sbin/nginx -t
server:~# /usr/sbin/chroot /usr/local/chroot/nginx /usr/local/nginx/nginx/sbin/nginx

 

c) Restart the chrooted nginx webserver – when necessery later

 

server:~# /usr/sbin/chroot /nginx /usr/local/chroot/nginx/sbin/nginx -s reload

 

d) Edit the chrooted nginx conf

If you need to edit nginx configuration, be aware that the chrooted NGINX will read its configuration from /usr/local/chroot/nginx/nginx/etc/conf/nginx.conf (i'm saying that if you by mistake forget and try to edit the old config that is usually under /usr/local/nginx/conf/nginx.conf

 

 

Install and use personal Own Cloud on Debian Linux for better shared data security – OwnCloud a Free Software replacement for Google Drive


August 23rd, 2018

owncloud-self-hosted-cloud-file-sharing-and-storage-service-for-gnu-linux-howto-install-on-debian

Basicly I am against the use of any Cloud type of service but as nowadays Cloud usage is almost inevitable and most of the times you need some kind of service to store and access remotely your Data from multiple devices such as DropBox, Google Drive, iCloud etc. and using some kind of infrastructure to execute high-performance computing is invitable just like the Private Cloud paid services online are booming nowdays, I decided to give a to research and test what is available as a free software in the field of Clouding (your data) 🙂

Undoubfully, it is really nice fact that there are Free Software / Open Source alternatives to run your Own personal Cloud to store your data from multiple locations on a single point.

The most popular and leading Cloud Collaboration service (which is OpenSource but unfortunately not under GPLv2 / GPV3 – e.g. not fully free software) is OwnCloud.

ownCloud is a flexible self-hosted PHP and Javascript based web application used for data synchronization and file sharing (where its remote file access capabilites are realized by Sabre/Dav an open source WebDav server.
OwnCloud allows end user to easily Store / Manage files, Calendars, Contacts, To-Do lists (user and group administration via OpenID and LDAP), public URLs can be easily, created, the users can interact with browser-based ODF (Open Document Format) word processor , there is a Bookmarking, URL Shortening service integrated, Gallery RSS Feed and Document Viewer tools such as PDF viewer etc. which makes it a great alternative to the popular Google Drive, iCloud, DropBox etc.

The main advantage of using a self-hosted Cloud is that Your data is hosted and managed by you (on your server and your hard drives) and not by some God knows who third party provider such as the upmentioned.
In other words by using OwnCloud you manage your own data and you don't share it ot on demand with the Security Agencies with CIA, MI6, Mussad … (as it is very likely most of publicly offered Cloud storage services keeps track on the data stored on them).

The other disadvantage of Cloud Computing is that the stored data on such is usually stored on multiple servers and you can never know for sure where your data is physically located, which in my opinion is way worse than the option with Self Hosted Cloud where you know where your data belongs and you can do whatever you want with your data keep it secret / delete it or share it on your demand.

OwnCloud has its clients for most popular Mobile (Smart Phone) platforms – an Android client is available in Google Play Store as well as in Apple iTunes besides the clients available for FreeBSD OS, the GNOME desktop integration package and Raspberry Pi.

For those who are looking for additional advanced features an Enterprise version of OwnCloud is also available aiming business use and included software support.

Assuming you have a homebrew server or have hired a dedidacted or VPS server (such as the Ones we provide) ,Installing OwnCloud on GNU / Linux is a relatively easy
task and it will take no more than 15 minutes to 2 hours of your life.
In that article I am going to give you a specific instructions on how to install on Debian GNU / Linux 9 but installing on RPM based distros is similar and straightfoward process.
 

1. Install MySQL / MariaDB database server backend
 

By default OwnCloud does use SQLite as a backend data storage but as SQLite stores its data in a file and is becoming quickly slow, is generally speaking slowre than relational databases such as MariaDB server (or the now almost becoming obsolete MySQL Community server).
Hence in this article I will explain how to install OwnCloud with MariaDB as a backend.

If you don't have it installed already, e.g. it is a new dedicated server install MariaDB with:
 

server:~# apt-get install –yes mariadb-server


Assuming you're install on a (brand new fresh Linux install – you might want to install also the following set of tools / services).

 

server:~# systemctl start mariadb
server:~# systemctl enable mariadb
server:~# mysql_secure_installation


mysql_secure_installation – is to finalize and secure MariaDB installation and set the root password.
 

2. Create necessery database and users for OwnCloud to the database server
 

linux:~# mysql -u root -p
MariaDB [(none)]> CREATE DATABASE owncloud CHARACTER SET utf8;
MariaDB [(none)]> GRANT ALL PRIVILEGES ON owncloud.* TO 'owncloud'@'localhost' IDENTIFIED BY 'owncloud_passwd';
MariaDB [(none)]> FLUSH PRIVILEGES;
MariaDB [(none)]> \q

 

3. Install Apache + PHP necessery deb packages
 

As of time of writting the article on Debian 9.0 the required packages for a working Apache + PHP install for OwnCloud are as follows.

 

server:~# apt-get install –yes apache2 mariadb-server libapache2-mod-php7.0 \
openssl php-imagick php7.0-common php7.0-curl php7.0-gd \
php7.0-imap php7.0-intl php7.0-json php7.0-ldap php7.0-mbstring \
php7.0-mcrypt php7.0-mysql php7.0-pgsql php-smbclient php-ssh2 \
php7.0-sqlite3 php7.0-xml php7.0-zip php-redis php-apcu

 

4. Install Redis to use as a Memory Cache for accelerated / better performance ownCloud service


Redis is an in-memory kept key-value database that is similar to Memcached so OwnCloud could use it to cache stored data files. To install latest redis-server on Debian 9:
 

server:~# apt-get install –yes redis-server

5. Install ownCloud software packages on the server

Unfortunately, default package repositories on Debian 9 does not provide owncloud server packages but only some owncloud-client packages are provided, that's perhaps the packages issued by owncloud does not match debian packages.

As of time of writting this article, the latest available OwnCloud server  version package for Debian is OC 10.

a) Add necessery GPG keys

The repositories to use are provided by owncloud.org, to use them we need to first add the necessery gpg key to verify the binaries have a legit checksum.
 

server:~# wget -qO- https://download.owncloud.org/download/repositories/stable/Debian_9.0/Release.key | sudo apt-key add –

 

b) Add owncloud.org repositories in separete sources.list file

 

server:~# echo 'deb https://download.owncloud.org/download/repositories/stable/Debian_9.0/ /' | sudo tee /etc/apt/sources.list.d/owncloud.list

 

c) Enable https transports for the apt install tool

 

server:~# apt-get –yes install apt-transport-https

 

d) Update Debian apt cache list files and install the pack

 

server:~# apt-get update

 

server:~# apt-get install –yes owncloud-files

 

By default owncloud store file location is /var/www/owncloud but on many servers that location is not really appropriate because /var/www might be situated on a hard drive partition whose size is not big enough, if that's the case just move the folder to another partition and create a symbolic link in /var/www/owncloud pointing to it …


6. Create necessery Apache configurations to make your new self-hosted cloud accessible
 

a) Create Apache config file

 

server:~# vim /etc/apache2/sites-available/owncloud.conf

 

 

Alias /owncloud "/var/www/owncloud/"

<Directory /var/www/owncloud/>
Options +FollowSymlinks
AllowOverride All

<IfModule mod_dav.c>
Dav off
</IfModule>

SetEnv HOME /var/www/owncloud
SetEnv HTTP_HOME /var/www/owncloud

</Directory>

b) Enable Mod_Dav (WebDAV) if it is not enabled yet

 

server:~# ln -sf ../mods-available/dav_fs.conf
server:~# ln -sf ../mods-available/dav_fs.load
server:~# ln -sf ../mods-available/dav.load
server:~# ln -sf ../mods-available/dav_lock.load

c) Set proper permissions for /var/www/owncloud to make upload work properly

 

chown -R www-data: /var/www/owncloud/


d) Restart Apache WebServer (to make new configuration affective)

 

 

server:~# /etc/init.d/apache2 restart


7. Finalize  OwnCloud Install
 

Access OwnCloud Web Interface to finish the database creation and set the administrator password for the New Self-Hosted cloud
 

http://Your_server_ip_address/owncloud/

By default the Web interface is accessible in unencrypted (insecure) http:// it is a recommended practice (if you already don't have an HTTPS SSL certificate install for the IP or the domain to install one either a self-signed certificate or even better to use LetsEncrypt CertBot to easily create a valid SSL for free for your domain

 

installing-OwnCloud-Web-Config-User-Pass-interface-Owncloud-10-on-Debian-9-Linux-howto

Just fill in in your desired user / pass and pass on the database user / password / db name (if required you can set also a different location for the data directory from the default one /var/www/owncloud/data.

Click Finish Setup and That's all folks!

owncloud-server-web-ui-interface

OwnCloud is successfully installed on the server, you can now go and download a Mobile App or Desktop application for whatever OS you're using and start using it as a Dropbox replacement. In a certain moment you might want to consult also the official UserManual documentation as you would probably need further information on how to manage your owncloud.

Enjoy !

How to mount LVM partition volume on Linux


August 22nd, 2018

lvm-logical-volume-logical-volume-groups

(LVM) = Logical Volume Manager is a device mapper offering logical volume management for the Linux kernel. Virtually all modern GNU / Linux distributions has support for it and using LVM is used among almost all Hosting Providers on (dedicated) backend physical and Virtual XEN / VMWare etc. servers because it provides the ability to merge a number of disks into virtual volumes (for example you have a number of SSD Hard Drives on a server that are under a separate /dev/sda1 /dev/sda2 /dev/sdb3 /dev/sdb4 etc. and you want all the HDDs to appear as a single file system this is managed by Linux LVM.

Logical-volume-manager-linux-explained-diagram.svg

Picture sources Wikipedia

The use of LVM is somewhat similar to RAID 0 disk arrays, where the good about it it allows the removal and addition of hard disks in real time (broken hard disks) on servers to be replaced without service downtime as well as dynamic HDD volume resizal is possible. LVM allows also relatively easy encryption of multiple HDD volumes
with single password.

Discs can be organized in volume groups (so lets say 2 of the server Attached conventional Hard Disks, SCSI or SSDs can be attached to LVM1 and another 3 Hard Drives could be attached to LVM2 group etc.

LVM has been an integral part of Linux kernel since 1998.

lvm is available for install via apt, yum, dhf etc. under a package called lvm2, so to install it on Debian / Ubuntu Fedora Linux (if it is not already installed on the servers with).

 

– Install LVM2 On Debian / Ubuntu
 

debian:~# apt-get install –yes lvm2

 


– Install LVM2 on Fedora / CentOS (Redhat RPM based distros)

 

[root@centos ~]:# yum install -y lvm2


or

[root@fedora ~]:#  dhf install -y lvm2


I. Mounting LVM2 on Linux server after broken DISK change part of a LVM Volume

For example the HDD faileddue to bad sectors and physical HDD head damage damage  – the easiest way to figure that out if the server is running smartd or via a simple HDD test check from BIOS  ( as the ROOT partition is on a LVM it fails to boot properly. You have changed the broken HDD with a brand new and you need to remount the LVM either physically on the server console or remotely via some kind of BIOS KVM interface).

In my experience working for Santrex this was a common sysadmin job, as many of the Virtual Client servers as well as others irons situated in various DataCenters, were occasionally failing to boot and the monitoring system was reporting about the issues and we had to promptly react and bring the servers up.

Here is shortly how we managed to re-mount the LVM after the SSDs / HDDS were substituted:

    1.1. Execute fdisk, vgscan / lvdisplay command

fdisk-lvm-screenshot

lvdisplay-screenshot

vgscan scans all supported LVM block devices in the system for VGs (Virtual Groups)

vgscan-vgchange-screenshot-lvm

    1.2. Next issue vgchange command to activate volume
 

vgchange -ay


   
    1.3. Type lvs command to get information about logical volumes

 

lvs


   
    1.4. Create a mount point using the mkdir command

      That's because we wanted to check the LVM will get properly mounted on next server reboot).
   
     1.5. Mount an LVM volume using
 

server:~# mount /dev/mapper/DEVICE /path/to/mount_point

 

     1.6. To check the size of the LVM (mount points, mounted LVM /dev/names sizes and the amount of free space on each of them use)
 

server:~# df -T