check Archives - Page 3 of 8 - ☩ Walking in Light with Christ - Faith, Computing, Diary ☩ Walking in Light with Christ

Posts Tagged ‘check’

Linux: How to sync user files with rsync on every root user logout – useful for Clusters

Monday, April 6th, 2020

rsync-how-to-transfer-locally-remotely-and-synchronize

For those who run Redhat Linux Enterprise servers / Suse Enterprise Linux or any other Linux distribution with some kind of Application clustering such as Pacemaker ( PCM ) / Corosync and OpenSSH
which are supposed to be always identical in terms of configurations files in /etc/ configurations of haproxy /etc/hosts* below are few steps to follow to always keep files from server1 to server2 the same.

1. Create rsyncuser on 1st machine and second machine

– Create user with useradd on node1 and node2 and generate RSA SSH key pair with ssh-keygen command.

– Copy id_rsa.pub from local server1 host to remote host server2

– Test and confirm remote passwordless authentication is working

– To make rsyncuser be able to copy files with root privileges

echo ‘rsyncuser ALL=NOPASSWD:/usr/bin/rsync’ >> /etc/sudoers

For indepth descriptions of above steps please check my previous artice
Rsync copy files with root privileges between servers with root superuser account disabled.

2. CREATE sync-commands file desired to be executed on logout from the system of the user into
some file like /root/sync_check.sh

root@host # vim /root/sync_check.sh
#!/bin/sh
# sync logout script
echo "###################checking sync Line1 and Line2 now ################"
rsync –dry-run –delete -avze 'ssh -i /home/rsyncuser/.ssh/id_rsa' '–rsync-path=sudo rsync' /etc/hosts.deny rsyncuser@server2:/etc/hosts.deny
rsync –dry-run –delete -avze 'ssh -i /home/rsyncuser/.ssh/id_rsa' '–rsync-path=sudo rsync' /etc/haproxy/certs/*.* rsyncuser@server2:/etc/haproxy/certs/
rsync –dry-run –delete -avze 'ssh -i /home/rsyncuser/.ssh/id_rsa' '–rsync-path=sudo rsync' /etc/haproxy/*.cfg rsyncuser@server2:/etc/haproxy/
echo "################### done sync_check.sh ################"

3. Edit root lougout-script /root/.bash_logout

root@host # vi /root/.bash_logout
== Append the following lines:
# ~ / .bash_logout
echo "################### run root bash_logout ################"
/root/sync_check.sh
echo "################### root logged out ################"
== Save and close the file.

– To make the rsync to sync some specific files such as user's personal home directory etc. and hence you need it to be user wide you can add the file to be executed for all users via
/etc/bashrc or /etc/profile

What you will have as a result is an an override copy of /etc/hosts.deny /etc/haproxy/certs* /etc/haproxy/*.cfg on each and every root logout.
The meaning of all this is to make sure this 3 files always stay identical, to prevent someone to mess up some configuration by mistake and on next haproxy standby / reload to not load with unworking config due to the user stupidity.

That's all folks. Test it and be happy 🙂

Tags: Account, ALL, and, ANY, application, are, authentication, bashrc, Below, between, bin, certs, cfg, check, checking, copy files, logout, rsync, script, synchronize user data on logout
Posted in Everyday Life, Linux, System Administration | No Comments »

LVM extend partition Linux howto and how to check if Logical Volume Manager partition is extendable

Thursday, February 13th, 2014

how-to-resize-extend-lvm-partitioned-hard-disks-logical_volume_manager_lvm_logo

Many Linux servers these days are using LVM (Logical Volume Manager) in order to allow disk drives and partitions to be easily managed (shrinked / resized). It is interesting fact LVM is successor of HP-UX's volume manager. LVM can be considered as a thin software layer on top of the hard disks and partitions, which creates an abstraction of continuity and ease-of-use for managing hard drive replacement, re-partitioning, and backup.

LVM is commonly used for the following purposes:

Managing large hard disk farms by allowing disks to be added and replaced without downtimes and services disruption (useful whenever hot-swapping is needed)
On small systems (like a desktop at home), instead of having to estimate at installation time how big a partition might need to be in the future.
– LVM lets file systems to be easily resized later as needed.
Performing consistent backups by taking snapshots of the logical volumes.
Creating single logical volumens of multiple physical volumes or entire hard disks (somewhat similar to RAID-0), ability to do dynamic volume resizing (in LVM partitions are volumes).

So if you're sysadmin it is quite likely that some LVM volume starts being filled up (because of bad initial planning), so the customer asks you to resize a LVM (volume), here is how to do it:

1. Check whether LVM configured on server has free disk space that can be relocated
First lets list all LVM configured volumes on server:

# vgscan Reading all physical volumes. This may take a while... Found volume group "web_log" using metadata type lvm2 Found volume group "web_all" using metadata type lvm2 Found volume group "rootvg" using metadata type lvm2

vgscan – scan all disks for volume groups and rebuild caches
Then lets display the volume group information.

This is done with vgdisplay cmd
# vgdisplay --- Volume group --- VG Name rootvg System ID Format lvm2 Metadata Areas 1 Metadata Sequence No 13 VG Access read/write VG Status resizable MAX LV 0 Cur LV 11 Open LV 11 Max PV 0 Cur PV 1 Act PV 1 VG Size 136.56 GB PE Size 8.00 MB Total PE 17480 Alloc PE / Size 7329 / 57.26 GB Free PE / Size 10151 / 79.30 GB VG UUID 27z2w0-Ku0H-y6M0-QFCR-3Rp6-c1HX-OTinzn

[root@lupus ~]# vgs
VG #PV #LV #SN Attr VSize VFree
VolGroup00 1 3 0 wz–n- 695.44G 0
[root@lupus ~]# pvs
PV VG Fmt Attr PSize PFree
/dev/sda3 VolGroup00 lvm2 a– 695.44G 0

Important line from above command output is (Free PE / Size 10151 / 79.30 GB). Indicating that server's LVM had 79.30 GB Free which can be used to extend any of the server LVM existing volumes.

Here are one of servers managed by me existing volumes:

# df -h Filesystem Size Used Avail Use% Mounted on /dev/mapper/rootvg-root 5.0G 301M 4.4G 7% / udev 18G 144K 18G 1% /dev tmpfs 42G 0 42G 0% /dev/shm /dev/cciss/c0d0p1 122M 28M 88M 24% /boot /dev/mapper/rootvg-home 512M 268M 219M 56% /home /dev/mapper/rootvg-opt 2.5G 484M 1.9G 21% /opt /dev/mapper/rootvg-Tivoli 3.0G 895M 2.0G 32% /opt/Tivoli /dev/mapper/rootvg-uc4 3.0G 289M 2.6G 11% /opt/uc4 /dev/mapper/rootvg-sysadm 3.0G 69M 2.8G 3% /sysadm /dev/mapper/rootvg-tmp 1.3G 35M 1.2G 3% /tmp /dev/mapper/rootvg-usr 4.0G 1.2G 2.6G 32% /usr /dev/mapper/rootvg-var 5.0G 500M 4.2G 11% /var /dev/mapper/rootvg-webservices 9.9G 4.0G 5.9G 41% /webservices

For instance lets say the task is to extend LVM (volume) partition:

/dev/mapper/rootvg-webservices 9.9G 4.0G 5.9G 41% /webservices

Lets say we want to extend /dev/mapper/rootvg/rootvg-webserices with 20 Gygabytes:

# lvextend -L20G /dev/mapper/rootvg-webservices

Then we we would like to add some extra 10GB:

# lvextend -L10G /dev/mapper/rootvg-webservices

In order to add all available LVM free space to a volume use:

# lvextend -l +100%FREE /dev/mapper/rootvg-webservices

Whether you had to do it on Linux with kernel 2.4.x and ext2 / ext3 FS:

# umount /dev/mapper/rootvg-webservices # resize2fs /dev/mapper/rootvg-webservices # mount /dev/mapper/rootvg /webservices

To resize ext4 filesystem with LVM above umount / resize2fs and mount commands can be safely skipped.

On other file systems to raise the size of the filesystem there are different tools to use also on some umount and mount is not necessary example for dynamicly resizable filesystem is reiserfs (though I don't recommend this FS to anyone as the creator of ReiserFS killed his family – moreover my personal experience with ReiserFS in past was quite bitter – I lost personal data because of ReiserFS break ups).

Here is how to dynamicly resize FS after lvextend on Reiserfs filesystem:

# resize_reiserfs -f /dev/myvg/homevol

XFS also supports resize of filesystem with no need to re-mount on server with XFS LVM resize after lvextend run:

# xfs_growfs /webservices

Tags: check, disk space, Display, filesystem, Filesystem Size Used Avail Use Mounted, FS, hard disks, howto, information, kernel 2, linux?, Logical Volume Manager, LVM, mapper, metadata, Metadata Areas, mount dev, partition, partitions, resize, server, servers, top, type
Posted in Linux, System Administration | No Comments »

How to check if shared library is loaded in AIX OS – Fix missing libreadline.so.7

Thursday, February 20th, 2020

ibm-aix-logo1

I've had to find out whether an externally Linux library is installed on AIX system and whether something is not using it.
The returned errors was like so:

# gpg –export -a

Could not load program gpg:
Dependent module /opt/custom/lib/libreadline.a(libreadline.so.7) could not be loaded.
Member libreadline.so.7 is not found in archive

After a bit of investigation, I found that gpg was failing cause it linked to older version of libreadline.so.6, the workaround was to just substitute the newer version of libreadline.so.7 over the original installed one.

Thus I had a plan to first find out whether this libreadline.a is loaded and recognized by AIX UNIX first and second find out whether some of the running processes is not using that library.
I've come across this interesting IBM official documenation that describes pretty good insights on how to determine whether a shared library is currently loaded on the system. which mentions the genkld command that is doing
exactly what I needed.

In short:
genkld – creates a list that is printed to the console that shows all loaded shared libraries

genkld-screenshot-aix-unix

Next I used lsof (list open files) command to check whether there is in real time opened libraries by any of the running programs on the system.

After not finding anything and was sure the library is neither loaded as a system library in AIX nor it is used by any of the currently running AIX processes, I was sure I could proceed to safely overwrite libreadline.a (libreadline.so.6) with libreadline.a with (libreadline.so.7).

The result of that is again a normally running gpg as ldd command shows the binary is again normally linked to its dependend system libraries.

aix# ldd /usr/bin/gpg
/usr/bin/gpg needs:
/usr/lib/threads/libc.a(shr.o)
/usr/lib/libpthreads.a(shr_comm.o)
/usr/lib/libpthreads.a(shr_xpg5.o)
/opt/freeware/lib/libintl.a(libintl.so.1)
/opt/freeware/lib/libreadline.a(libreadline.so.7)
/opt/freeware/lib/libiconv.a(libiconv.so.2)
/opt/freeware/lib/libz.a(libz.so.1)
/opt/freeware/lib/libbz2.a(libbz2.so.1)
/unix
/usr/lib/libcrypt.a(shr.o)
/opt/freeware/lib/libiconv.a(shr4.o)
/usr/lib/libcurses.a(shr42.o)

# gpg –version
gpg (GnuPG) 1.4.22
Copyright (C) 2015 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

Home: ~/.gnupg
Supported algorithms:
Pubkey: RSA, RSA-E, RSA-S, ELG-E, DSA
Cipher: IDEA, 3DES, CAST5, BLOWFISH, AES, AES192, AES256, TWOFISH,
CAMELLIA128, CAMELLIA192, CAMELLIA256
Hash: MD5, SHA1, RIPEMD160, SHA256, SHA384, SHA512, SHA224
Compression: Uncompressed, ZIP, ZLIB, BZIP2

Tags: AES, aes256, AIX, check, Cipher, command, find, first, found, freeware, How to, idea, installed, libraries, RSA, running processes, substitute, system, using, version
Posted in AIX, Everyday Life, System Administration | No Comments »

How to unlock AIX user UNIX account / Reset failed login count

Thursday, January 30th, 2020

As part of my daily sysadmin job I had to unlock the user of a colleague who had been locked on some obscure AIX UNIX machine.
IBM AIX Operating System is used mainly for corporate crtical applications within Airports, Financial institutions Banks, U.S Army, Navy, the Stock Exchange etc.

Due to its complexity and price and the lack of people with any expertise, it is now only used for a critical businesses for its great possibilities of Native Application clustering etc.

But enough rant if you happen to come around AIX and need to reset failed login counter which is part of AIX integrated Login Security and blocks the user
after a preset count number here is how.

1. Become superuser

# su – root

2. Check the number of previous unsucessful logins for the account to confirm it is blocked

# lsuser -a unsuccessful_login_count <userid>

i.e.

# lsuser -a unsuccessful_login_count hipo
hipo unsuccessful_login_count=10

3. Reset unsucessful login counter

# chsec -f /etc/security/lastlog -a unsuccessful_login_count=0 -s hipo

4. Unlock the locked account

# chuser account_locked=false hipo

5. Lock account

If for some reason you need to lock some old and no longer used user (instead of completely deleting it).

# chuser account_locked=true hipo

6. Check account lock / unlock state

# lsuser hipo
hipo id=2086 pgrp=group groups=users,admin home=/home/hipo shell=/usr/bin/bash gecos=Official Name login=true su=true rlogin=true daemon=true admin=false sugroups=ALL admgroups= tpath=nosak ttys=ALL expires=0 auth1=SYSTEM auth2=NONE umask=7 registry=files SYSTEM=compat logintimes= loginretries=3 pwdwarntime=14 account_locked=false minage=1 maxage=13 maxexpired=12 minalpha=1 minloweralpha=0 minupperalpha=0 minother=1 mindigit=1 minspecialchar=0 mindiff=3 maxrepeats=2 minlen=8 histexpire=40 histsize=10 pwdchecks= dictionlist= default_roles= fsize=2097151 cpu=-1 data=262144 stack=65536 core=2097151 rss=65536 nofiles=2000 time_last_login=XXXXXXXXXXXX time_last_unsuccessful_login=XXXXXXXXXXX tty_last_login=ssh tty_last_unsuccessful_login=ssh host_last_login=10.10.10.1 host_last_unsuccessful_login=1.2.3.4 unsuccessful_login_count=0 roles=

7. How to reset failed login counter on RedHat / CentOS Linux

Corporate Linux distributions like RHEL / CentOS and SLES have also a similar security feature that allows the sysadmin to block user after a number of unsucessful login count.
To unblock a prohibited to login user, less say due to multiple failure to remember his own password do:

[root@linux: ~]# pam_tally2 –user=Username pam_tally2 –user=Username –reset

Tags: Account, admin, after, AIX, ALL, allows, and, ANY, application, applications, Army, around, bin, Blocks, CentOS, centos linux, check, colleague, complexity, core
Posted in AIX, Linux, System Administration | No Comments »

Check when Windows Active Directory user expires and set user password expire to Never

Thursday, January 9th, 2020

If you're working for a company that is following high security / PCI Security Standards and you're using m$ Windows OS that belongs to the domain it is useful to know when your user is set to expiry
to know how many days are left until you'll be forced to change your Windows AD password.
In this short article I'll explain how to check Windows AD last password set date / date expiry date and how you can list expiry dates for other users, finally will explain how to set your expiry date to Never
to get rid of annoying change password every 90 days.

1. Query domain Username for Password set / Password Expires set dates

To know this info you need to know the Password expiration date for Active Directory user account, to know it just open Command Line Prompt cmd.exe

And run command:

NET USER Your-User-Name /domain

net-user-domain-command-check-AD-user-expiry

Note that, many companies does only connect you to AD for security reason only on a VPN connect with something like Cisco AnyConnect Secure Mobility Client whatever VPN connect tool is used to encrypt the traffic between you and the corporate DMZ-ed network

Below is basic NET USER command usage args:

Net User Command Options

Item Explanation

net user   Execute the net user command alone to show a very simple list of every user account, active or not, on the computer you're currently using.

username   This is the name of the user account, up to 20 characters long, that you want to make changes to, add, or remove. Using username with no other option will show detailed information about the user in the Command Prompt window.

password   Use the password option to modify an existing password or assign one when creating a new username. The minimum characters required can be viewed using the net accounts command. A maximum of 127 characters is allowed1.
*   You also have the option of using * in place of a password to force the entering of a password in the Command Prompt window after executing the net user command.

/add   Use the /add option to add a new username on the system.
options   See Additional Net User Command Options below for a complete list of available options to be used at this point when executing net user.

/domain   This switch forces net user to execute on the current domain controller instead of the local computer.

/delete   The /delete switch removes the specified username from the system.

/help   Use this switch to display detailed information about the net user command. Using this option is the same as using the net help command with net user: net help user.
/?   The standard help command switch also works with the net user command but only displays the basic command syntax. Executing net user without options is equal to using the /? switch.

2. Listing all Active Directory users last set date / never expires and expiration dates

If you have the respective Active Directory rights and you have the Remote Server Administration Tools for Windows (RSAT Tools), you are able to do also other interesting stuff,

such as

– using PowerShell to list all user last set dates, to do so use Open Power Shell and issue:

get-aduser -filter * -properties passwordlastset, passwordneverexpires |ft Name, passwordlastset, Passwordneverexpires

get-aduser-properties-passwordlastset-passwordneverexpires1

This should show you info as password last set date and whether password expiration is set for account.

– Using PS to get only the password expirations for all AD existing users is with:

Get-ADUser -filter {Enabled -eq $True -and PasswordNeverExpires -eq $False} –Properties "DisplayName", "msDS-UserPasswordExpiryTimeComputed" |
Select-Object -Property "Displayname",@{Name="ExpiryDate";Expression={[datetime]::FromFileTime($_."msDS-UserPasswordExpiryTimeComputed")}}

If you need the output data to get stored in CSV file delimitered format you can add to above PS commands

| export-csv YOUR-OUTPUT-FILE.CSV

3. Setting a user password to never Expiry

If the user was created with NET USER command by default it will have been created to have a password expiration.
However if you need to create new users for yourself (assuming you have the rights), with passwords that never expire on lets say Windows Server 2016 – (if you don't care about security so much), use:

NET USER "Username" /Add /Active:Yes

WMIC USERACCOUNT WHERE "Name='Username' SET PasswordExpires=False

NET-USER-ADD_Active-yes-Microsoft-Windows-screenshot

NET-USER-set-password-policy-to-Never-expiry-MS-Windows

To view the general password policies, type following:

NET ACCOUNTS

Tags: active, check, directory, User, when, Windows
Posted in Curious Facts, Everyday Life, Various, Windows | No Comments »

Getting Console and Graphical hardware system information on Linux with cpuinfo, neofetch, CPU-X (CPU-Z Unix alternative), I-nex and inxi

Tuesday, September 17th, 2019

getting-console-information-and-graphical-hardware-system-information-Linux-cpuinfo-neofetch-cpu-x-i-nex-1

Earlier I've wrote extensive article on how to get hardware information on Linux using tools such as dmidecode, hardinfo, lshw, hwinfo, x86info and biosdecode but there are few other hardware reporting tools for Linux worthy to mention that has been there for historical reasons such as cpuinfo as we as some new shiny ones such as neofetch (a terminal / console hardware report tool as well the CPU-X and I-Nex which is Linux equivalent to the all known almost standard for Windows hardware detection CPU-Z worthy to say few words about.

1. cpuinfo

Perhaps the most basic tool to give you a brief information about your Processor type (model) number of Cores and Logical Processors is cpuinfo

I remember cpuinfo has been there since the very beginning on almost all Linux distributions's repository, nowadays its popularity of the days when the kings on the Linux OS server scenes were Slackware, Caldera OpenLinux and Redhat 6.0 Linux and Debian 3.0 declined but still for scripting purposes it is handy small proggie.

To install and run it in Debian / Ubuntu / Mint Linux etc.:

aptitude install -y cpuinfo
…
/usr/bin/cpu-info

2. neofetch

The next one worthy to install and check is neofetch (a cross-platform and easy-to-use system information
command line script that collects your Linux system information and display it on the terminal next to an image, it could be your distributions logo or any ascii art of your choice.)

The cool thing about neofetch is besides being able to identify the System server / desktop hardware parameters, it gives some basic info about number of packages installed on the system, memory free and in use, used kernel and exact type of System (be it Dell PowerEdge Model XX, IBM eSeries Model / HP Proliant Model etc.

neofetch info generated on my home used Lenovo Thikpad T420

neofetch-OS-hardware-information-Linux-ascii-system-info-pcfreak-home-server
neofetch info from www.pc-freak.net running current machine

neofetch even supports Mac OS X and Windows OS ! 🙂

To install neofetch on Mac OS X:

/usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

or via Mac ported packages using brew

brew install neofetch

neofetch-screenshot-from-Mac-OS-X

neofetch is even installable on Windows OS that has the scoop command line installer tool installer manager with below PowerShell code in cmd.exe (Command line):

powershell Set-ExecutionPolicy RemoteSigned -scope CurrentUser
iex (new-object net.webclient).downloadstring('https://get.scoop.sh')
scoop install git
scoop install neofetch

neofetch-microsoft-windows-hardware-command-line-report-tool-screenshot

By the way Scoop was quite a finding for me and it is pretty handy to install plenty of useful command line Linux / UNIX tools, such as curl, wget, git etc. in the same easy straight forward way as a standard yum or apt-get on Windows (without explicitly installing things as GnuWin and CygWin).

3. CPU-X graphical user interface hardware report Linux GUI alternative to Windows CPU-Z

The packages for CPU-X are a bit outdated and even though there are rpm packages for Fedora, OpenSuSE and .deb package for Debian for Debian, Ubuntu and ArchLinux (pacman), there is no up to date version for Debian 10 and the package builds distributed for different Linux distros are a bit outdated.

Thus to install CPU-X on any Linux distribution it is perhaps best to use the portable version (static binary) of CPU-X.
It is currently available on https://github.com/X0rg/CPU-X/releases

To install latest portable version of CPU-X

wget https://github.com/X0rg/CPU-X/releases/download/v3.2.4/CPU-X_v3.2.4_portable.tar.gz
…
mkdir CPU-X
cd CPU-X
tar -zxvvf CPU-X_v3.2.4_portable.tar.gz
-rwxr-xr-x yohan/users 4563032 2019-01-13 22:15 CPU-X_v3.2.4_portable.bsd64
-rwxr-xr-x yohan/users 5484968 2019-01-13 22:15 CPU-X_v3.2.4_portable.linux64

cp -rpf CPU-X_v3.2.4_portable.linux64 /usr/local/bin/
ln -sf /usr/local/bin/CPU-X_v3.2.4_portable.linux64 /usr/local/bin/cpu-x

Next run as superuser (root)

hipo@jeremiah:~$ su -c 'cpu-x'

As seen from below screenshots cpu-x reports a lot of concrete specific hardware data on:

Processor
Motherboard
Memory
System
Graphic card
Performance

cpu-x-cpu-cpu-z-alternative-linux-screenshot-CPU-info

cpu-x-cpu-cpu-z-alternative-linux-screenshot-caches-info

cpu-x-cpu-cpu-z-alternative-linux-screenshot-Motherboard-info

cpu-x-cpu-cpu-z-alternative-linux-screenshot-memory-info

cpu-x-cpu-cpu-z-alternative-linux-screenshot-system-info

cpu-x-cpu-cpu-z-alternative-linux-screenshot-graphics-info

CPU-X can be installed also on FreeBSD very easily by just installing from BSD port tree sysutils/cpu-x/
It is also said to work on other *BSDs, NetBSD, OpenBSD Unixes but I guess this will require a manual compilation based on FreeBSD's port Makefile.

4. I-Nex another GUI alternative to CPU-Z for UNIX / Linux

I-Nex is even more useful for general hardware reporting as it reports many hardware specifications not reported by CPU-X such as Battery type and Model Name (if the hardware report is on a laptop), info on USB devices slots or plugged USB devices brand and specifications, the available Network devices on the system (MAC Addresses) of each of it, Installed and used drivers on Hard Disk (ATA / SATA / SCSI / SSD), HW Sector size, Logical Block size, HDD Sectors count and other specific Hard Drive data as well as information on available Audio (Sound Blaster) devices (HDA-Intel), used Codecs, loaded kernel ALSA driver, Video card used and most importantly indicators on Processor reported CPU (temperature).

To install I-nex

Go to https://launchpad.net/i-nex or any of the mirror links where it resides and install the respective package, in my case, I was doing the installation on Debian Linux, so fetched current latest amd64 package which as of moment of writting this article is i-nex_7.6.0-0-bzr977-20161012-ubuntu16.10.1_amd64.deb , next installed it with dpkg

dpkg -i i-nex_7.6.0-0-bzr977-20161012-ubuntu16.10.1_amd64.deb

As the package was depending on some other .deb packages, which failed to install to install the missing ones I had to further run

apt –fix-broken install

i-nex-cpu-info-linux-hardware-info-program

hre

I-Nex thermal indicators about CPU temperature on a Linux Desktop notebook

There are other Hardware identification report tools such as CUDA-Z – that are useful to check if you have Nvidia Video Card hardware Installed on the PC to check the status of CUDA enabled GPUs, useful if working with nVidia Geforce, Quadro, Tesla cards and ION chipsets.

If you use it however be aware that CUDA-Z is not compatible with 3rd-party linux drivers for NVidia so make sure you have the current official Nvidia version.

5. Inxi full featured system information script

Inxi is a 10000 lines mega bash script that fetches hardware details from multiple different sources in /proc /sys and from commands on the system, and generates a beautiful looking console report that non technical users can read easily.

inxi-10-k-mega-bash-shell-script-reporting-on-installed-system-computer-hardware

inxi -Fx

inxi-report-on-installed-hardware-on-my-lenovo-thinkpad-home-laptop

Each of the pointed above tools has different method of collection of Hardware information from various resources e.g. – kernel loaded modules, dmesg, files like /proc/meminfo /proc/version /proc/scsi/scsi /proc/partitions.
Hence some of the tools are likely to report more info than otheres, so in case if some information you need regarding the system plugged in hardware is missing you can perhaps obtain it from another program. Most Linux distribution desktop provided GNOME package are including Hardinfo gui tool, but in many cases above mentioned tools are likely to add even more on info on what is inside your PC Box.
If you're aware of others tools that are useful not mentioned here please share it.

Tags: ArchLinux, basic, check, command, cpu-x, cpuinfo, deb packages, Debian Ubuntu Mint Linux, finding, Graphical, hardware, i-nex, installed, inxi, Lenovo Thikpad T420, line script, machine, netofetch, number, OpenBSD, packages, plenty, Processor Motherboard Memory System Graphic, report, system information, terminal, tool, user interface, usr bin, version, wget, Windows
Posted in Linux, Linux and FreeBSD Desktop, System Administration | No Comments »

Check the count and monitor of established / time_wait TCP, UDP connections on Linux and Windows with netstat command

Wednesday, February 6th, 2019

netstat-windows-linux-commands-to-better-understand-your-server-type-of-networrk-tcp-udp-connections

For me as a GNU / Linux sysadmin it is intuitive to check on a server the number of established connections / connections in time_wait state and so on .

I will not explain why this is necessery as every system administrator out there who had a performance or network issues due to server / applications connection overload or have been a target of Denial of Service (DoS)
or Distributed Denial of Service attacks (DDoS) is well aware that a number of connections in different states such as SYN_ACK / TIME_WAIT or ESTABLISHED state could be very nasty thing and could cause a productive application or Infrastructure service to be downed for some time causing from thousands of Euros to even millions to some bussinesses as well as some amount of data loss …

To prevent this therefore sysadmins should always take a look periodically on the Connection states on the adminned server (and in this number I say not only sys admins but DevOps guys who are deploying micro-services for a customer in the Cloud – yes I believe Richard Stallman is right here they're clouding your minds :).

Even though cloud services could provide a very high amount of Hardware (CPU / Memory / Storage) resources, often for custom applications migrating the application in the Cloud does not solve it's design faults or even problems on a purely classical system administration level.

1. Get a statistic for FIN_WAIT1, FOREIGN, SYNC_RECV, LAST_ACK, TIME_WAIT, LISTEN and ESTABLISHED Connections on GNU / Linux

On GNU / Linux and other Linux like UNIXes the way to do it is to grep out the TCP / UDP connection type you need via netstat a very useful cmd in that case is:

root@pcfreak:~# netstat -nat | awk '{print $6}' | sort | uniq -c | sort -n
1 established)
1 FIN_WAIT1
1 Foreign
1 SYN_RECV
3 LAST_ACK
4 FIN_WAIT2
8 TIME_WAIT
45 LISTEN
147 ESTABLISHED

2. Netstat 1 liner to Get only established and time_wait connections state

Other ways to check only TCP ESTABLISHED connections on Linux I use frequently are:

root@pcfreak:~# netstat -etna|grep -i establi|wc -l
145

netstat-connection-types-statistics-linux-established-time-wait-check-count

Or to get whole list of connections including the ones who are about to be esatablished in FIN_WAIT2, TIME_WAIT, SYN_RECV state:

root@pcfreak:~# netstat -tupen |wc -l
164

3. Other Linux useful one liner commands to track your connection types

netstat -n -p | grep SYN_REC | sort -u

List out the all IP addresses involved instead of just count.

netstat -n -p | grep SYN_REC | awk '{print $5}' | awk -F: '{print $1}'

List all the unique IP addresses of the node that are sending SYN_REC connection status.

netstat -ntu | awk '{print $5}' | cut -d: -f1 | sort | uniq -c | sort -n

Use netstat command to calculate and count the number of connections each IP address makes to the server.

netstat -anp |grep 'tcp\|udp' | awk '{print $5}' | cut -d: -f1 | sort | uniq -c | sort -n

List count of number of connections the IPs are connected to the server using TCP or UDP protocol.

netstat -ntu | grep ESTAB | awk '{print $5}' | cut -d: -f1 | sort | uniq -c | sort -nr

Check on ESTABLISHED connections instead of all connections, and displays the connections count for each IP.

netstat -plan|grep :80|awk {'print $5'}|cut -d: -f 1|sort|uniq -c|sort -nk 1

Show and list IP address and its connection count that connect to port 80 on the server. Port 80 is used mainly by HTTP web page request.

Examples are taken from this nice blog post

4. Check the count of esatblished connections on M$ Windows

As I'm forced to optimize a couple of Microsoft Windows DNS servers which are really slow to resolve the
The logical question for me was how the Established and TIME_WAIT state connections then could be checked on Windows OS, after a quick investigation online I've come up with this:

C:\Users\admin> netstat -nao | find /i "estab" /c
78

C:\Users\admin> netsatt -nao | find /i "time_wait" /c
333

If you're used to Linux watch command, then to do same on Windows OS (e.g. check the output of netstat) command every second
and print output use:

netstat –an 1 | find “3334”

Below commands will show stats for services listening on TCP port 3334

To find out which process on system sends packets to remote destination:

netstat –ano 1 | find “Dest_IP_Addr”

The -o parameter outputs the process ID (PID) responsible for the connection.
then if you need further you can find the respective process name with tasklist< cmd.
Another handy Windows netstat option is -b which will show EXE file running as long as
the related used DLL Libraries which use TCP / UDP .

Other useful netsatat Win example is to grep for a port and show all established connections for it with:

netstat –an 1 | find “8080” | find “ESTABLISHED”

5. Closure

Hopefully this article will give you some idea on what is eating your bandwidth connections or overloading your GNU / Linux – Windows systems. And will point you to the next in line logical thing to do optimization / tuning
settings to be made on your system for example if Linux with sysctl – see my previous relater article here

I'll be intested to hear from sysadm colleagoes for other useful ways to track connections perhaps with something like ss tool (a utility to investigate sockets).
Also any optimization hints that would cause servers less downtime and improve network / performance thouroughput is mostly welcome.

Tags: check, connections, count, ESTABLISHED, monitor, time_wait
Posted in Linux, System Administration, Windows | No Comments »

Build and install Docker Squid Open Proxy image on Kubernetes cluster

Tuesday, October 30th, 2018

As Docker containerization is starting to become a standard for installing a brand new servers especially servers who live in Self-Made Clusters based on Orchestration technologites like Kubernetes (k8s) (check out – http://kubernetes.io),

Recently, I've had the task to set-up a Squid Cache (Open Proxy) server on a custom Port number to make it harder for internet open proxy scanners to identify and ship it to a customer.

What is Squid Open Proxy?

An open proxy is a proxy server that is accessible by any Internet user, in other words anyone could access the proxy without any authentication.

Squid is a caching proxy for the Web supporting HTTP, HTTPS, FTP and other protocols.
It reduces bandwidth and improves response times by caching and reusing frequently-requested web pages.
Squid has extensive access controls and makes a great server accelerator.
It runs on most available operating systems, including Windows and is licensed under the GNU GPL.

What is Docker?

For those who hear about Docker for a first time, Docker is an open-source software platform to create, deploy and manage virtualized application containers on a common OS such as GNU / Linux or Windows, it has a surrounding ecosystem of tools. Besides its open source version there is also a commercial version of the product by Docker Inc. the original company that developed docker and is today in active help of the project.

Docker components – picture source docker.com

What is Kubernetes?

Kubernetes, in short, is an open source system for managing clusters of containers. To do this, it provides tools for deploying applications, scaling those application as needed, managing changes to existing containerized applications, and helps you optimize the use of the underlying hardware beneath your containers.
Kubernetes is designed to be extensible and fault-tolerant by allowing application components to restart and move across systems as needed.

Kubernetes is itself not a Platform as a Service (PaaS) tool, but it serves as more of a basic framework, allowing users to choose the types of application frameworks, languages, monitoring and logging tools, and other tools of their choice. In this way, Kubernetes can be used as the basis for a complete PaaS to run on top of; this is the architecture chosen by the OpenShift Origin open source project in its latest release.

Kubernetes architecture (shortly explained) – picture source Wikipedia

The Kubernetes project is written in the Google developed Go programming language, and you can browse its source code on GitHub.

Hence, In this article I'll give a brief introuduction on what is Docker and show you, how to easily:

a. Build Docker Image with Ubuntu, Update the system and Install Squid inside the container
using a sample Dockerfile build file

b. Run Docker Image to test deployed Ubuntu Linux and Squid on top of it works fine

c. Push Docker Image to DockerHub (Docker Images Central Official repository)

d. Deploy (Pull and Run) the new built Docker Ubuntu / Squid Open Proxy Image to the Kubernetes Cluster slave nodes – the K8S Cluster was created using Rancher Enterprise Kubernetes Platform (check out Rancher.net – a bleeding edge tool for k8s quick GUI cluster creation / integration)

1. Install Docker Containerization Software Community Edition

Docker containers are similar to virtual machines, except they run as normal processes (containers), that does not use a Hypervisor of Type 1 or Type 2 and consume less resources than VMs and are easier to manage, nomatter what the OS environment is.

Docker uses cgroups and namespace to allow independent containers to run within a single Linux instance.

Docker Architecture – Picture source docker.com

Below docker install instructions are for Debian / Ubuntu Linux, the instructions for RPM package distros Fedora / CentOS / RHEL are very similar except yum or dnf tool is to be used.

a) Uninstall older versions of docker , docker-engine if present

apt-get -y remove docker docker-engine docker.io

! Previously running docker stuff such as Volumes, Images and networks will be preserved in /var/lib/docker/

b) install prerequired packages and add apt repositories for doko

apt-get update
apt-get install -y apt-transport-https ca-certificates wget software-properties-common

wget https://download.docker.com/linux/debian/gpg
apt-key add gpg
rm -f gpg

Create docker.list apt sources file

echo "deb [arch=amd64] https://download.docker.com/linux/debian $(lsb_release -cs) stable" | sudo tee -a /etc/apt/sources.list.d/docker.list

apt-get update

c) check out the docker policy (will list you a multiple installable versoins of docker).

apt-cache policy docker-ce

docker-ce:
Installed: (none)
Candidate: 17.06.0~ce-0~debian
Version table:
     17.06.0~ce-0~debian 500
        500 https://download.docker.com/linux/debian stretch/stable amd64 Packages
     17.03.2~ce-0~debian-stretch 500
        500 https://download.docker.com/linux/debian stretch/stable amd64 Packages
     17.03.1~ce-0~debian-stretch 500
        500 https://download.docker.com/linux/debian stretch/stable amd64 Packages
     17.03.0~ce-0~debian-stretch 500

d) Install and run docker

apt-get -y install docker-ce
systemctl start docker

systemctl status docker

Previously running docker stuff such as Volumes, Images and networks will be preserved in /var/lib/docker/

2. Build Docker image with Ubuntu Linux OS and Squid inside

To build a docker image all you need to do is have the Dockerfile (which is docker definitions build file), an Official image of Ubuntu Linux OS (that is provided / downloaded from dockerhub repo) and a bunch of docker commands to use apt / apt-get to install the Squid Proxy inside the Docker Virtual Machine Container

In dockerfile it is common to define for use an entrypoint.sh which is file with shell script commands definitions, that gets executed immediately after Docker fetches the OS from its remote repository on top of the newly run OS. It is pretty much like you have configured your own Linux distribution like using Linux from Scratch! to run on a bare-metal (hardware) server and part of the installation OS process you have made the Linux to run a number of scripts or commands during install not part of its regular installation process.

a) Go to https://hub.docker.com/ and create an account for free

The docker account is necessery in order to push the built docker image later on.
Creating the account creates just few minutes time.

b) Create a Dockerfile with definitions for Squid Open Proxy setup

I'll not get into details on the syntax that Dockerfile accepts, as this is well documented on Docker Enterprise Platform official website but in general gettings the basics and starting it is up to a 30 minutes to maximum 1h time.

After playing a bit to achieve the task to have my Linux distribution OS (Ubuntu Xenial) with Squid on installed on top of it with the right configuration of SQUID Cacher to serve as Open Proxy I've ended up with the following Dockerfile.

FROM ubuntu:xenial
LABEL maintainer="hipo@www.pc-freak.net"

ENV SQUID_VERSION=3.5.12-1ubuntu7 \
    SQUID_CACHE_DIR=/var/spool/squid \
    SQUID_LOG_DIR=/var/log/squid \
    SQUID_USER=proxy

RUN apt-get update \
&& apt-get upgrade && apt-get dist-upgrade && DEBIAN_FRONTEND=noninteractive apt-get install -y squid=${SQUID_VERSION}* \
&& rm -rf /var/lib/apt/lists/*

COPY entrypoint.sh /sbin/entrypoint.sh
COPY squid.conf /etc/squid/squid.conf
RUN chmod 755 /sbin/entrypoint.sh

EXPOSE 3128/tcp
ENTRYPOINT [“/sbin/entrypoint.sh”]

You can download the Dockerfile here.

c) Create entrypoint.sh and squid.conf files

Apart from that I've used the following entrypoint.sh (which creates and sets necessery caching and logging directories and launches script on container set-up) permissions for SQUID proxy file that is loaded from the Dockerfile on docker image build time.
To have the right SQUID configuration shipped up into the newly built docker container, it is necessery to prepare a template configuration file – which is pretty much a standard squid.conf file with the following SQUID Proxy configuration for Open Proxy

acl SSL_ports port 443
acl CONNECT method CONNECT

http_access deny !Safe_ports

http_access deny CONNECT !SSL_ports

http_access allow localhost manager
http_access deny manager

http_access allow localhost

http_access allow all

http_port 3128

coredump_dir /var/spool/squid

refresh_pattern ^ftp:           1440    20%     10080
refresh_pattern ^gopher:        1440    0%      1440
refresh_pattern -i (/cgi-bin/|\?) 0     0%      0
refresh_pattern (Release|Packages(.gz)*)$      0       20%     2880
refresh_pattern .               0       20%     4320

Once, I've created, the proper Dockerfile configuration, I've made a tiny shell script, that can create / re-create my docker image multiple times.
Here is the build-docker-image.sh :

#!/bin/sh
username='hipod';
password='';
docker login –username="$username" –password=""
DOCKER_ACC=hipod
#DOCKER_REPO=squid-3.5.12-1ubuntu7
DOCKER_REPO=squid-ubuntu
IMG_TAG=latest

docker build -t $DOCKER_ACC/$DOCKER_REPO:$IMG_TAG .
docker push $DOCKER_ACC/$DOCKER_REPO:$IMG_TAG

– You can download build-docker-image.sh script here

The script uses the docker login command to authenticate non-interactively to https://hub.docker.com
docker build command with properly set DOCKER_ACC (docker account – which is the username of your hub.docker.com account as I've pointed earlier in article), then DOCKER_REPO (docker repository name) – you can get it either from a browser, after you've logged in to dockerhub or assuming you know your username, it should look like:
https://hub.docker.com/u/your-username-name – for example mine is hipod with repository name squid-ubuntu, my squid-ubuntu docker image build is here, you'll also need to provide the password inside the script or if you consider it a security concern, instead type manually from command line docker login and authenticate in advance before running the script, finally the last line docker push pushes to remote docker hub the new build of Ubuntu + SQUID Proxy with a predefined TAG that in my case is latest (as this is my latest build of Squid – if you need a multiple version number of Squid repository just change the tag to the version tag line number.

d) Use the script to build Squid docker image

Next run the script to make and push into docker your new image:

sh build-docker-image.sh

Please consider that in order to work with docker hub push / pull, you will need to have a firewall that allows connection to dockerhub site repo, if for some reason the push / pull fails, check closely your firewall as it is the most likely cause for failure.

3. Run the new docker image to test Squid runs as expected

To make sure the docker image runs properly, you can test it on any machine that has docker.io installed, this is done with a simple cmd:

docker run -d –restart=always -p 3128:3128 hipod/squid-ubuntu:latest

The -d option tells docker to background process / run in detached mode
-p option tells docker to expose port (e.g. make NAT with iptables from the docker virtual container with Linux OS + SQUID listening inside the container on port 3128 to the TCP / IP 3128 server port).
You can use iptables to check the created Network Address Translation rules.

–restart=always option sets the docker restart policy (e.g. when the container is terminating it tells the container to restart the container (OS) after exit), there, you can use as a resetart policy (no, on-failure[:max_retries] , unless-stopped)

For clarity I've created one liner script run-squid.sh you can download here.

sh run-squid.sh

You can use a

ps aux|grep -i docker

root     13169 0.2 0.4 591300 77984 ?        Ssl 13:50   0:09 /usr/bin/dockerd -H fd://
root     13176 0.0 0.2 408244 34972 ?        Ssl 13:50   0:03 docker-containerd –config /var/run/docker/containerd/containerd.toml
root     20875 0.0 0.0 132348   948 pts/1    S+   14:52   0:00 grep -i docker

to see it running as well as the:

docker ps -a

CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS                      PORTS               NAMES
d2eb7ab635cf        c5b0f61227cd        "/bin/sh -c 'apt-get…"   12 minutes ago      Exited (1) 3 minutes ago                        trusting_elion
18476f546562        c5b0f61227cd        "/bin/sh -c 'apt-get…"   37 minutes ago      Exited (1) 37 minutes ago                       admiring_wilson

To connect to the running container later you can use docker attach ID_of_container

docker attach d2eb7ab635cf

command to see the new container runs as well as attach to the newly spawned container

**4. Deploying Dockerized SQUID Open Proxy Cache server to Kubernetes cluster**

My task was to deploy the newly built squid doko image to remote K8s cluster which was set as a default cluster via a context in .kube/config/ or manually set via:

kubectl config use-context my.k8s-cluster.net

I've used the following YAML file with kubectl to deploy:

—
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
labels:
    app: squid-app-33128
name: squid-app-33128
spec:
replicas: 1
template:
    metadata:
      labels:
        app: squid-app-33128
    spec:
      containers:
        – name: squid
          image: hipod/squid-ubuntu:latest
          imagePullPolicy: Always
          ports:
          – containerPort: 3128
            protocol: TCP
          volumeMounts:
            – mountPath: /var/spool/squid
              name: squid-cache
            – mountPath: /var/log/squid
              name: squid-log
          livenessProbe:
            tcpSocket:
              port: 3128
            initialDelaySeconds: 40
            timeoutSeconds: 4
      volumes:
        – name: squid-cache
          emptyDir: {}
        – name: squid-log
          emptyDir: {}

The task included to deploy two different Open Proxy squid servers on separate ports in order to add them external cluster Ingress load balancing via Amazon AWS, thus I actually used following 2 yaml files.

1. squid-app-33128.yaml
2. squid-app-33129.yaml

The actual deployment command was like that:

# deploys pods and adds services to kubernetes cluster

kubectl create -f squid-app-33129.yaml -f squid-app-33128.yaml -f squid-service-33129.yaml squid-service-33128.yaml

You can download the 2 squid-service .yaml below:

1. squid-service-33129.yaml
2. squid-service-33128.yaml

The service is externally exposed via later configured LoadBalancer to make the 2 squid servers deployed into k8s cluster accessible from the Internet by anyoneone without authorization (as a normal open proxies) via TCP/IP ports 33128 and 33129.

Conclusion

Below I explained a few easy steps to follow to;

– build docker image Ubuntu + Squid
– test the image
– deploy the image into a previously prepared k8s cluster

Though it all looks quite simplistic I should say creating the .yaml file took me long. Creating system configuration is not as simple as using the good old .conf files and getting used with the identation takes time.

Now once the LB are configured to play with k8s, you can enjoy the 2 proxy servers. If you need to do some similar task and you don't have to do it for a small fee, contact me.

Tags: applications, apt-get, brand, bunch, cause, check, cmd, command, configured, created, Creating, definitions, Docker Open Proxy, Docker Virtual Machine Container, download, file, fine, Install Docker Containerization Software Community Edition, kind, line, liner, make, metadata, NAT, necessery, need, number, properly, pull, repository, running, server port, servers, shell script, simple, Squid Cache Open Proxy, standard, system, tag, task, tcp, top, use, username, website
Posted in Cloud services, Docker, Educational | No Comments »

Install JBL Go Bluetooth Speaker on Debian GNU / Linux and Ubuntu

Thursday, August 24th, 2017

Here is how to configure a JBL Go Bluetooth (Wireless) speaker and presumably other Bluetooth external speakers to Debian GNU / Linux Wheezy 7 and Ubuntu 14.04 . 1. Install following bunch of deb packages

debian:~# apt-get install pulseaudio pulseaudio-module-bluetooth pavucontrol bluez-firmware

Here it is notable to mention pavucontrol if you have previously played more extensively on GNU / Linux you should have already used if not it is really cozy volume control tool with a lot of tuning options regarding pulseaudio stream server. Considering that like me you're using a GNOME as a desktop environment you will also need gnome-bluetooth package, e.g.:

debian:~# apt-get install gnome-bluetooth

As Pulseaudio is used as a sound streaming server in GNU / Linux (assuming your Debian version is using it you'll also need to have installed pulseaudio-module-bluetooth)

debian:~# apt-get install pulseaudio-module

For Ubuntu 14.04 GNU / Linux users the list of necessery bluetooth packages is a bit longer, if you're on this OS go and install:

debian:~# apt-get install bluez bluez-alsa bluez-audio bluez-btsco bluez-compat bluez-cups bluez-dbg bluez-gstreamer bluez-hcidump bluez-pcmcia-support bluez-tools bluez-utils python-bluez bluewho indicator-bluetooth libbluetooth-dev libgnome-bluetooth11 libbluetooth3 python-gobject python-dbus

Moreover you will need pulseaudio-module-bluetooth deb package installed in order to be able to select the desired sound output.

Next it is time to restart Bluetooth service

debian:~# service bluetooth restart [ ok ] Stopping bluetooth: rfcomm /usr/sbin/bluetoothd. [ ok ] Starting bluetooth: bluetoothd rfcomm.

It is also a good idea to restart pulseaudio snd streaming server in order to load the newly installed pulseaudio bluetooth module settings, to do so issue:

debian:~# killall pulseaudio

And try to establish connection from Gnome-Bluetooth to the JBL Go (press the JBL Go bluetooth button) and search from the Linux bluetooth interface, once founded connect it.

bluetooth-new-device-setup

jbl-go-connected-screenshot

Before JBL Go appears to list listable blootooth devices you will also need to run following command:

debian:~# pactl load-module module-bluetooth-discover 26

This command is to connect bluetooth discovered JBL Go device to the audio sink interface.

It is generally idea to add this line also to /etc/rc.local to make the setting permanently executed on every Linux boot.

Now you can launch pavucontrol and hopefully the JBL GO bluetooth speaker should be visible as an option, check out my below screenshot:

In case you further experience issues connecting the Bluetooth Speaker I would recommend to check out this Debian a2dp page at the end of the page are troubleshooting suggestions.

Troubleshooting

Refused to switch profile to a2dp_sink: Not connected

Bluetooth headset is connected, but ALSA/PulseAudio fails to pick up the connected device or there's no device to pick. This happens because GDM captures A2DP sink on session start, as GDM needs pulseaudio in the gdm session for accessibility. For example, the screen reader requires it. See 805414 for some discussion.

Workaround 1: disable pulseaudio in gdm

In order to prevent GDM from capturing the A2DP sink on session start, edit /var/lib/gdm3/.config/pulse/client.conf (or create it, if it doesn't exist):

autospawn = no
daemon-binary = /bin/true

After that you have to grant access to this file to Debian-gdm user:

chown Debian-gdm:Debian-gdm /var/lib/gdm3/.config/pulse/client.conf

You will also need to disable pulseaudio startup:

rm /var/lib/gdm3/.config/systemd/user/sockets.target.wants/pulseaudio.socket

In order to auto-connect a2dp for some devices, add this to /etc/pulse/default.pa:

load-module module-switch-on-connect

Logout your Desktop environment and restart gdm3 /etc/init.d/gdm3 restart or Reboot the PC and then it should be fine.

Now the sound device (bluetooth headset) should be accessible through pavucontrol and standard audio device manager.

Workaround 2: disable pulseaudio's bluetooth in gdm

The actual solution package maintainers are looking into next is to simply disable the bluetooth sink in the gdm pulseaudio daemon so that it doesn't take over the device. Add this to /var/lib/gdm3/.config/pulse/default.pa:

#!/usr/bin/pulseaudio -nF
#
# load system wide configuration
.include /etc/pulse/default.pa
### unload driver modules for Bluetooth hardware
.ifexists module-bluetooth-policy.so
unload-module module-bluetooth-policy
.endif
.ifexists module-bluetooth-discover.so
unload-module module-bluetooth-discover
.endif

Though this article explains how to connect a bluetooth speaker connecting Bluetooth Speaker to GNU / Linux is done in analogous way

Tags: check, Debian, idea, Install, list, need, page, pulseaudio, server, volume control
Posted in Curious Facts, Entertainment, Everyday Life, Linux, Linux Audio & Video | 1 Comment »

How to check Linux OS install date / How long ago was Linux installed

Sunday, October 22nd, 2017

If you're sysadmin who inherited a few hundreds of Linux machines from a previous admin and you're in process of investigating how things were configured by the previous administrator one of the crucial things to find out might be

How Long ago was Linux installed?

Here is how to check the Linux OS install date.

The universal way nomatter the Linux distribution is to use fullowing command:

root@pcfreak:~# tune2fs -l /dev/sda1 | grep 'Filesystem created:'
Filesystem created: Thu Sep 6 21:44:22 2012

Above command assumes the Linux's root partition / is installed on /dev/sda1 however if your case is different, e.g. the primary root partition is installed on /dev/sda2 or /dev/sdb1 / dev/sdb2 etc. just place the right first partition into the command.

If primary install root partition is /dev/sdb1 for example:

root@pcfreak:~# tune2fs -l /dev/sdb1 | grep 'Filesystem created:'

To find out what is the root partition of the Linux server installed use fdisk command:

root@pcfreak:~# fdisk -l

Disk /dev/sda: 465,8 GiB, 500107862016 bytes, 976773168 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x00051eda

Device     Boot     Start       End   Sectors   Size Id Type
/dev/sda1 *         2048 965193727 965191680 460,2G 83 Linux
/dev/sda2       965195774 976771071 11575298   5,5G 5 Extended
/dev/sda5       965195776 976771071 11575296   5,5G 82 Linux swap / Solaris

Disk /dev/sdb: 111,8 GiB, 120034123776 bytes, 234441648 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x00000000

Other ways to check the Linux OS install date on Debian / Ubuntu / Mint etc. deb. based GNU / Linux

Deban based Linux distributions do create an initial /var/log/installer directory containing various install information such as hardware-summary, partition, initial installed deb packages, exact version of Linux distribution, and the way it was installed either it was installed from an ISO image, or it was network install etc.

root@pcfreak:~# ls -al /var/log/installer/
total 1228
drwxr-xr-x 3 root root   4096 sep 6 2012 ./
drwxr-xr-x 72 root root 12288 окт 22 06:26 ../
drwxr-xr-x 2 root root   4096 sep 6 2012 cdebconf/
-rw-r–r– 1 root root 17691 sep 6 2012 hardware-summary
-rw-r–r– 1 root root    163 sep 6 2012 lsb-release
-rw——- 1 root root 779983 sep 6 2012 partman
-rw-r–r– 1 root root 51640 sep 6 2012 status
-rw——- 1 root root 363674 sep 6 2012 syslog

If those directory is missing was wiped out by the previous administrator, to clear up traces of his previous work before he left job another possible way to find out exact install date is to check timestamp of /lost+found directory;

root@pcfreak:~# ls -ld /lost+found/
drwx—— 2 root root 16384 sep 6 2012 /lost+found//

Check OS Linux install date on (Fedora, CentOS, Scientific Linux, Oracle and other Redhat RPM based Distros)

[root@centos: ~]# rpm -qi basesystem
Name        : basesystem
Version     : 10.0
Release     : 7.el7
Architecture: noarch
Install Date: Mon 02 May 2016 19:20:58 BST
Group       : System Environment/Base
Size        : 0
License     : Public Domain
Signature   : RSA/SHA256, Tue 01 Apr 2014 14:23:16 BST, Key ID     199e2f91fd431d51
Source RPM : basesystem-10.0-7.el7.src.rpm
Build Date : Fri 27 Dec 2013 17:22:15 GMT
Build Host : ppc-015.build.eng.bos.redhat.com
Relocations : (not relocatable)
Packager    : Red Hat, Inc. <http://bugzilla.redhat.com/bugzilla>
Vendor      : Red Hat, Inc.
Summary     : The skeleton package which defines a simple Red Hat Enterprise Linux system
Description :
Basesystem defines the components of a basic Red Hat Enterprise Linux
system (for example, the package installation order to use during
bootstrapping). Basesystem should be in every installation of a system,
and it should never be removed.

Tags: administrator, check, Device Boot Start End Sectors Size Id Type, filesystem, hardware, How to, how to check linux install date, howto, info, initial, Install, Linux, partition, pcfreak, root root, sector size, use
Posted in Linux, System Administration | No Comments »

☩ Walking in Light with Christ – Faith, Computing, Diary

Posts Tagged ‘check’

How to check if shared library is loaded in AIX OS – Fix missing libreadline.so.7

Check when Windows Active Directory user expires and set user password expire to Never

1. Query domain Username for Password set / Password Expires set dates

2. Listing all Active Directory users last set date / never expires and expiration dates

3. Setting a user password to never Expiry

Build and install Docker Squid Open Proxy image on Kubernetes cluster

1. Install Docker Containerization Software Community Edition

2. Build Docker image with Ubuntu Linux OS and Squid inside

3. Run the new docker image to test Squid runs as expected

**4. Deploying Dockerized SQUID Open Proxy Cache server to Kubernetes cluster**

Conclusion

Daily Bible quote

GET ARTICLE UPDATES

Useful blog? Help it:

Links to Other Places

Recent Posts

Ads

Categories

About Myself

Recent Comments

Top Post Views

blogtopsites

Posts Tagged ‘check’

1. Create rsyncuser on 1st machine and second machine

2. CREATE sync-commands file desired to be executed on logout from the system of the user into some file like /root/sync_check.sh

3. Edit root lougout-script /root/.bash_logout

1. Become superuser

2. Check the number of previous unsucessful logins for the account to confirm it is blocked

3. Reset unsucessful login counter

4. Unlock the locked account

5. Lock account

6. Check account lock / unlock state

7. How to reset failed login counter on RedHat / CentOS Linux

1. Query domain Username for Password set / Password Expires set dates

2. Listing all Active Directory users last set date / never expires and expiration dates

3. Setting a user password to never Expiry

1. cpuinfo

2. neofetch

3. CPU-X graphical user interface hardware report Linux GUI alternative to Windows CPU-Z

5. Inxi full featured system information script

1. Get a statistic for FIN_WAIT1, FOREIGN, SYNC_RECV, LAST_ACK, TIME_WAIT, LISTEN and ESTABLISHED Connections on GNU / Linux

2. Netstat 1 liner to Get only established and time_wait connections state

3. Other Linux useful one liner commands to track your connection types

Examples are taken from this nice blog post

5. Closure

1. Install Docker Containerization Software Community Edition

2. Build Docker image with Ubuntu Linux OS and Squid inside

3. Run the new docker image to test Squid runs as expected

4. Deploying Dockerized SQUID Open Proxy Cache server to Kubernetes cluster

Conclusion

Refused to switch profile to a2dp_sink: Not connected

Workaround 1: disable pulseaudio in gdm

Workaround 2: disable pulseaudio's bluetooth in gdm

Daily Bible quote

GET ARTICLE UPDATES

Useful blog? Help it:

Links to Other Places

Recent Posts

Ads

Categories

About Myself

Recent Comments

Tags

Top Post Views

blogtopsites

2. CREATE sync-commands file desired to be executed on logout from the system of the user into
some file like /root/sync_check.sh

**4. Deploying Dockerized SQUID Open Proxy Cache server to Kubernetes cluster**