Posts Tagged ‘host’

Why du and df reporting different on a filesystem / How to fix inconsistency between used space on FS and disk showing full strangeness

Wednesday, July 24th, 2019

linux-why-du-and-df-shows-different-result-inconsincy-explained-filesystem-full-oddity

If you're a sysadmin on a large server environment such as a couple of hundred of Virtual Machines running Linux OS on either physical host or OpenXen / VmWare hosted guest Virtual Machine, you might end up sometimes at an odd case where some mounted partition mount point reports its file use different when checked with
df
cmd than when checked with du command, like for example:
 

root@sqlserver:~# df -hT /var/lib/mysql
Filesystem   Type  Size Used Avail Use% Mounted On
/dev/sdb5      ext4    19G  3,4G    14G  20% /var/lib/mysql

Here the '-T' argument is used to show us the filesystem.

root@sqlserver:~# du -hsc /var/lib/mysql
0K    /var/lib/mysql/
0K    total

 

1. Simple debug on what might be the root cause for df / du inconsistency reporting

 

Of course the basic thing to do when in that weird situation is to be totally shocked how this is possible and to investigate a bit what is the biggest first level sub-directories that eat up the space on the mounted location, with du:

 

# du -hkx –max-depth=1 /var/lib/mysql/|uniq|sort -n
4       /var/lib/mysql/test
8       /var/lib/mysql/ezmlm
8       /var/lib/mysql/micropcfreak
8       /var/lib/mysql/performance_schema
12      /var/lib/mysql/mysqltmp
24      /var/lib/mysql/speedtest
64      /var/lib/mysql/yourls
144     /var/lib/mysql/narf
320     /var/lib/mysql/webchat_plus
424     /var/lib/mysql/goodfaithair
528     /var/lib/mysql/moonman
648     /var/lib/mysql/daniel
852     /var/lib/mysql/lessn
1292    /var/lib/mysql/gallery

The given output is in Kilobytes so it is a little bit hard to read, if you're used to Mbytes instead, do

 

 # du -hmx –max-depth=1 /var/lib/mysql/|uniq|sort -n|less

 

I've also investigated on the complete /var directory contents sorted by size with:

 

 # du -akx ./ | sort -n
5152564    ./cache/rsnapshot/hourly.2/localhost
5255788    ./cache/rsnapshot/hourly.2
5287912    ./cache/rsnapshot
7192152    ./cache


Even after finding out the bottleneck dirs and trying to clear up a bit, continued facing that inconsistently shown in two commands and if you're likely to be stunned like me and try … to move some files to a different filesystem to free up space or assigned inodes with a hope that shown inconsitency output will be fixed as it might be caused  due to some kernel / FS caching ?? and this will eventually make the mounted FS to refresh …

But unfortunately, if you try it you'll figure out clearing up a couple of Megas or Gigas will make no difference in cmd output.

In my exact case /var/lib/mysql is a separate mounted ext4 filesystem, however same issue was present also on a Network Filesystem (NFS) and thus, my first thought that this is caused by a network failure problem or NFS bug turned to be wrong.

After further short investigation on the inodes on the Filesystem, it was clear enough inodes are available:
 

# df -i /var/lib/mysql
Filesystem       Inodes  IUsed   IFree IUse% Mounted on
/dev/sdb5      1221600  2562 1219038   1% /var/lib/mysql

 

So the filled inodes count assumed issue also has been rejected.
P.S. (if you're not well familiar with them read manual, i.e. – man 7 inode).
 

– Remounting the mounted filesystem

To make sure the filesystem shown inconsistency between du and df is not due to some hanging network mount or bug, first logical thing I did is to remount the filesytem showing different in size, in my case this was done with:
 

# mount -o remount,rw -t ext4 /var/lib/mysql

For machines with NFS remote mounted storage locations, used:

# mount -o remount,rw -t nfs /var/www


FS remount did not solved it so I continued to ponder what oddity and of course I thought of a workaround (in case if this issues are caused by kernel bug or OS lib issue) reboot might be the solution, however unfortunately restarting the VMs was not a wanted easy to do solution, thus I continued investigating what is wrong …

Next check of course was to check, what kind of network connections are opened to the affected hosts with:
 

# netstat -tupanl


Did not found anything that might point me to the reported different Megabytes issue, so next step was to check what is the situation with currently opened files by running processes on the weird df / du reported systems with lsof, and boom there I observed oddity such as multiple files

 

# lsof -nP | grep '(deleted)'

COMMAND   PID   USER   FD   TYPE DEVICE    SIZE NLINK  NODE NAME
mysqld   2588  mysql    4u   REG 253,17      52     0  1495 /var/lib/mysql/tmp/ibY0cXCd (deleted)
mysqld   2588  mysql    5u   REG 253,17    1048     0  1496 /var/lib/mysql/tmp/ibOrELhG (deleted)
mysqld   2588  mysql    6u   REG 253,17       777884290     0  1497 /var/lib/mysql/tmp/ibmDFAW8 (deleted)
mysqld   2588  mysql    7u   REG 253,17       123667875     0 11387 /var/lib/mysql/tmp/ib2CSACB (deleted)
mysqld   2588  mysql   11u   REG 253,17       123852406     0 11388 /var/lib/mysql/tmp/ibQpoZ94 (deleted)

 

Notice that There were plenty of '(deleted)' STATE files shown in memory an overall of 438:

 

# lsof -nP | grep '(deleted)' |wc -l
438


As I've learned a bit online about the problem, I found it is also possible to find deleted unlinked files only without any greps (to list all deleted files in memory files with lsof args only):

 

# lsof +L1|less


The SIZE field (fourth column)  shows a number of files that are really hard in size and that are kept in open on filesystem and in memory, totally messing up with the filesystem. In my case this is temp files created by MYSQLD daemon but depending on the server provided service this might be apache's www-data, some custom perl / bash script executed via a cron job, stalled rsync jobs etc.
 

2. Check all the list open files with the mysql / root user as part of the the server filesystem inconsistency debugging with:

 

– Grep opened files on server by user

# lsof |grep mysql
mysqld    1312                       mysql  cwd       DIR               8,21       4096          2 /var/lib/mysql
mysqld    1312                       mysql  rtd       DIR                8,1       4096          2 /
mysqld    1312                       mysql  txt       REG                8,1   20336792   23805048 /usr/sbin/mysqld
mysqld    1312                       mysql  mem       REG               8,21      24576         20 /var/lib/mysql/tc.log
mysqld    1312                       mysql  DEL       REG               0,16                 29467 /[aio]
mysqld    1312                       mysql  mem       REG                8,1      55792   14886933 /lib/x86_64-linux-gnu/libnss_files-2.28.so

 

# lsof | grep root
COMMAND    PID   TID TASKCMD          USER   FD      TYPE             DEVICE   SIZE/OFF       NODE NAME
systemd      1                        root  cwd       DIR                8,1       4096          2 /
systemd      1                        root  rtd       DIR                8,1       4096          2 /
systemd      1                        root  txt       REG                8,1    1489208   14928891 /lib/systemd/systemd
systemd      1                        root  mem       REG                8,1    1579448   14886924 /lib/x86_64-linux-gnu/libm-2.28.so

Other command that helped to track the discrepancy between df and du different file usage on FS is:
 

# du -hxa  / | egrep '^[[:digit:]]{1,1}G[[:space:]]*'
 

 

3. Fixing large files kept in memory filesystem problem


What is the real reason for ending up with this file handlers opened by running backgrounded programs on the Linux OS?
It could be multiple  but most likely it is due to exceeded server / client interactions or breaking up RAM or HDD drive with writing plenty of logs on the FS without ending keeping space occupied or Programming library bugs used by hanged service leaving the FH opened on storage.

What is the solution to file system files left in memory problem?

The best solution is to first fix custom script or hanged service and then if possible to simply restart the server to make the kernel / services reload or if this is not possible just restart the problem creation processes.

Once the process is identified like in my case this was MySQL on systemd enabled newer OS distros, just do:

 

 

# systemctl restart mysqld.service


or on older init.d system V ones:

# /etc/init.d/service restart


For custom hanged scripts being listed in ps axuwef you can grep the pid and do a kill -HUP (if the script is written in a good way to recognize -HUP and restart the sub-running process properly – BE EXTRA CAREFUL IF YOU'RE RESTARTING BROKEN SCRIPTS as this might cause your running service disruptions …).

# pgrep -l script.sh
7977 script.sh


# kill -HUP PID

 

Now finally this should either mitigate or at best case completely solve the reported disagreement between df and du, after which the calculated / reported disk space should be back to normal and show up approximately the same (note that size changes a bit as mysql service is writting data) constantly extending the size between the two checks.

 

# df -hk /var/lib/mysql; du -hskc /var/lib/mysql
Filesystem       Inodes  IUsed   IFree IUse% Mounted on
/dev/sdb5        19097172 3472744 14631296  20% /var/lib/mysql
3427772    /var/lib/mysql
3427772    total

 

What we learned?

What I've explained in this article is why and how it comes that 'zoombie' files reside on a filesystem
appearing to be eating disk space on a mounted local or network partition, giving strange inconsistent
reports, leading to system service disruptions and impossibility to have correctly shown information on used
disk space on mounted drive.

I went through with some standard logic on debugging service / filesystem / inode issues up explainat, that led me to the finding about deleted files being kept in filesystem and producing the filesystem strange sized / showing not correct / filled even after it was extended with tune2fs and was supposed to have extra 50GBs.

Finally it was explained shortly how to HUP / restart hanging script / service to fix it.

Some few good readings that helped to fix the issue:

What to do when du and df report different usage is here
df in linux not showing correct free space after file removal is here
Why do “df” and “du” commands show different disk usage?
 

How to synchronize with / from Remote FTP server using LFTP like with rsync

Sunday, October 15th, 2017

how-to-synchronize-from-remote-ftp-server-easily-like-rsync.jpg

Have you ever been in a need to easily synchronize with a remote host which only runs FTP server?

Or are you in a local network and you need to mirror a directory or a couple of directories in a fast and easy to remember way?

If so then you'll be happy to use below LFTP command that is doing pretty much the same as Rsync, with only difference that it can mirror files over FTP (old but gold File Transfer Protocol).
 

lftp -u FTP_USERNAME,FTP_PASSWORD -e 'mirror REMOTE_DIRECTORY LOCAL_DIRECTORY' FTP_SERVER_HOSTNAME


Enjoy and thanks to my dear friend Amridikon for the tip ! 🙂

How to share your Windows local drives via Remote Desktop (RDP) – Safe file copy with RDP protocol

Tuesday, October 14th, 2014

remote-desktop-connection-options-button-screenshot

Just had a task to install Tomcat 7, Java JRE 1.7 and .NET Framework 3.5 and MS Visual C++ x86 on a Windows 2008 RC2 system situated behind a firewalled network NAT. To do the installation I had to use a special jump host (which was also a MS Windows system). The end system where installation had to occur did not have access to the Internet was in special DMZ-ed network so to install above 3 software packages I had to transfer them from my notebook to install host.
To depic what had to happen, I had to:

Transfer files from (host A – my notebook) -> via host (B – jump host) to host (C – the end install host).

Default Windows RDP Client command (mstsc.exe) supports transferring files between host A and RDP-ed host B via standard file copy / paste, so I tried transferring files between my work Windows PC to (jump host B), by copy pasting the files, but as the DotNetFx35Client.exe file was 261 Megabytes and the network between host A and B has some shapings and network firewalls the file transfer timed out. Copy / Paste method via RDP Protocol by default, doesn’t support Transfer Resume thus in order to transfer the 261 MB file, I tried Sharing C:Temp Folder and transfer that way, but unfortunately I didn’t have the permissions in that Windows Domain to create sharings (even though on the remote system I was already logged in with admin accounts). I’ve consulted a colleague on advise on how to transfer the files and I was told about a Win RDP client option to share drives.

Here is how to share your PC drive letters C: D: E: etc. via Remote Desktop Protocol


1. Run mstsc.exe

2. Click the Options button

remote-desktop-connection-options-button-screenshot

3. Click Local Resources tab

4. Click More button

remote-desktop-connection-more-options-button-screenshot

5. Click on Drives

remote-desktop-connection-share-windows-disk-drives-option-screenshot

Then after connecting to the Remote RDP host, all your local PC drive partitions C: D: E: will be visible as (attached) ones in mounted in My Computer / MS Explorer with assigned new drive letters

Once, I transferred the .NET Framework 3.5 while using the installer I was notified that .NET Framework 3.5 is by default included in Windows 8 and I need only to enable it.

To enable .NET Framework 3.5 in Windows 8 from Control Panel

Choose Programs, and then choose Turn Windows features on or off.

Select the .NET Framework 3.5 (includes .NET 2.0 and 3.0) check box.
enable-dot-net-framework-windows-8-windows-8.1-add-feature-screenshot

Preserve domain name after redirect with mod_rewrite and some useful mod rewrite redirect and other examples – Redirect domain without changing URL

Friday, July 11th, 2014

redirect_domain_name_without_changing_url_apache_rewrite_rule_preventing_host_in_ip_mod_rewrite
If you're a webhosting company sysadmin, sooner or later you will be asked by application developer or some client to redirect from an Apache webserver to some other webserver / URL's IP, in a way that the IP gets preserved after the redirect.

I'm aware of two major ways to do the redirect on webserver level:

1. To redirect From Apache host A to Webserver on host B using ReverseProxy mod_proxy

2. To use Mod Rewrite to redirect all client requests on host A to host B.

There is quite a lot to be said and is said and written online on using mod_rewrite to redirect URLs.
So in this article I will not say nothing new but just present some basic scenarios on Redirecting with mod rewrite and some use cases.
Hope this examples, will help some colleague sys-admin to solve some his crazy boss redirection tasks 🙂 I'm saying crazy boss because I already worked for a  start-up company which was into internet marketing and the CEO has insane SEO ideas, often impossible to achieve …

a) Dynamic URL Redirect from Apache host A to host B without changing domain name in browser URL and keeping everything after the query in

Lets say you want to redirect incoming traffic to DomainA to DomainB keeping whole user browser request, i.e.

Redirect:

http://your-domainA.com/whole/a/lot/of/sub/directory/query.php


Passthe the whole request including /whole/a/lot/of/sub/directory/query.php

so when Apache redirects to redirect to:

http://your-domainB.com/whole/a/lot/of/sub/directory/query.php

In browser 
To do it with Mod_Rewrite either you have to add in .htaccess mod_rewite rules:

RewriteEngine On
RewriteCond %{HTTP_HOST} ^your-domainA.com [OR]
RewriteCond %{HTTP_HOST} ^http://your-domainA.com
RewriteRule ^(.*) http://your-domainB.com/$1 [P]

or include this somewhere in VirtualHost configuration of your domain
 

Above mod_rewrite will make any request to your-domainA.com to forward to your-domainB.com while preserving the hostname in browser URL bar to old domain http://your-domainA.com, however still contet will be served by http://your-domainB.com
 

http://yourdomainA.com/YOUR-CUSTOM-REQUEST-ADDRESS


to redirect to

http://yourdomainB.com/YOUR-CUSTOM-REQUEST-ADDRESS


WARNING !!  If you're concerned about your SEO well positioning in search Engines, be sure to never ever use such redirects. Making such redirects will cause two domains to show up duplicate content
and will make Search Engines to reduce your Google, Yahoo, Yandex etc. Pagerank !!

Besides that such, redirect will use mod_rewrite on each and every redirect so from performance stand point it is a CPU killer (for such redirect using native mod_proxy ProxyPass is much more efficient – on websites with hundred of thousands of requests daily using such redirects will cause you to spend your  hardware badly  …)

P.S. ! Mod_Rewrite and Proxy modules needs to be previously enabled
On Debian Linux, make sure following links are existing and pointing to proper existing files from /etc/apache2/mods-available/ to /etc/apache2/mods-enabled

debian:~#  ls -al /etc/apache2/mods-available/*proxy*
-rw-r–r– 1 root root  87 Jul 26  2011 /etc/apache2/mods-available/proxy_ajp.load
-rw-r–r– 1 root root 355 Jul 26  2011 /etc/apache2/mods-available/proxy_balancer.conf
-rw-r–r– 1 root root  97 Jul 26  2011 /etc/apache2/mods-available/proxy_balancer.load
-rw-r–r– 1 root root 803 Jul 26  2011 /etc/apache2/mods-available/proxy.conf
-rw-r–r– 1 root root  95 Jul 26  2011 /etc/apache2/mods-available/proxy_connect.load
-rw-r–r– 1 root root 141 Jul 26  2011 /etc/apache2/mods-available/proxy_ftp.conf
-rw-r–r– 1 root root  87 Jul 26  2011 /etc/apache2/mods-available/proxy_ftp.load
-rw-r–r– 1 root root  89 Jul 26  2011 /etc/apache2/mods-available/proxy_http.load
-rw-r–r– 1 root root  62 Jul 26  2011 /etc/apache2/mods-available/proxy.load
-rw-r–r– 1 root root  89 Jul 26  2011 /etc/apache2/mods-available/proxy_scgi.load

debian:/etc/apache2/mods-avaialble:~# ls *proxy*
proxy.conf@  proxy_connect.load@  proxy_http.load@  proxy.load@


If it is is not enabled to enable proxy support in Apache on Debian / Ubuntu Linux, either create the symbolic links as you see them from above paste or issue with root:
 

a2enmod proxy_http
a2enmod proxy

 

b) Redirect Main Domain requests to other Domain specific URL
 

RewriteEngine On
RewriteCond %{HTTP_HOST} ^your-domainA.com
RewriteRule ^(.*) http://your-domainB.com/YOUR-CUSTOM-URL [P]

Note that no matter what kind of subdirectory you request on http://your-domain.com (lets say you type in http://your-domainA.com/My-monkey-sucks ) it will get redirected to:

http://your-domainB.com/YOUR-CUSTOM-URL

Sometimes this is convenient for SEO, because it can make you to redirect any requests (including mistakenly typed requests by users or Bot Crawlers to real existing landing page).

c) Redirecting an IP address to a Domain Name

This probably a very rare thing to do as usually a Domain Name is redirected to an IP, however if you ever need to redirect IP to Domain Name:

RewriteCond %{HTTP_HOST} ^##.##.##.##
RewriteRule (.*) http://your-domainB.com/$1 [R=301,L]

Replace ## with digits of your IP address, the is used to escape the (.) – dots are normally interpreted by mod_rewrite.

d) Rewritting URL extensions from .htm to .php, doc to docx etc.

Lets say you're updating an old website with .htm or .html to serve .php files with same names as old .htmls use following rewrite rules:. Or all your old .doc files are converted and replaced with .docx and you need to make Apache redirect all .doc requests to .docx.
 

Options +FollowSymlinks
RewriteEngine on
RewriteRule ^(.*).html$ $1.php [NC]

Options +FollowSymlinks
RewriteEngine on
RewriteRule ^(.*).doc$ $1.docx [NC]

The [NC] flag at the end means "No Case", or "case-insensitive"; Meaning it will not matter whether files are requested with capital or small letters, they will just show files if file under requested name is matched.

Using such a redirect will not cause Apache to redirect old files .html, .htm, .doc and they will still be accessible again creating duplicate content which will have a negavite impact on Search Engine Optimization.

The better way to do old extensioned files redirect is by using:

Options +FollowSymlinks
RewriteEngine on
RewriteRule ^(.+).htm$ http://your-domainB.com/$1.php [R,NC]

[R] flag would tell make mod_rewrite send HTTP "MOVED TEMPORARILY" redirection, aka, "302" to browser. This would cause search engines and other spidering entities will automatically update their links to the new locations.

e) Grabbing content from URL with Mod Rewrite and passing it to another domain

Lets say you want zip files contained in directory files/ to be redirected from your current webserver on domainA to domainB's download.php script and be passed as argument to the script

Options +FollowSymlinks
RewriteEngine on
RewriteRule ^files/([^/]+)/([^/]+).zip http://www.pc-freak.net/download.php?section=$1&file=$2 [R,NC]


f) Shortening URLs with mod_rewrite

This is ueful If you have a long URL address accessible via some fuzzy long hard to remember URL address and you want to make it acessible via a shorter URL without phyisally moving the files within a short named directory, do:

Options +FollowSymlinks
RewriteEngine On
RewriteRule ^james-brown /james-brown/files/download/download.php

Above rule would make requests coming to http://your-domain.com/james-brown?file=my.zip be opened via http://mysite/public/james-brown/files/download/download.php?file=my.zip

g) Get rid of the www in your domain name

Nowdays many people are used to typing www.your-domain.com, if this annoys you and you want them not to see in served URLs the annoying www nonsense, use this:

Options +FollowSymlinks
RewriteEngine on
RewriteCond %{http_host} ^www.your-domain.com [NC]
RewriteRule ^(.*)$ http://your-domain.com/$1 [R=301,NC]

That's mostly some common uses of mod rewrite redirection, there are thousands of nice ones. If you know others, please share?


References and thanks to:

How to redirect domain without changing the URL

More .htaccess tips and tricks – part 2

 

 

Linux: Virtualbox shared folder – how to share files from host to guest OS in Virtualbox

Monday, June 9th, 2014

add-shared-folder-in-virtualbox-linux-virtual-machine-on-top-of-windows-howto

If you just installed Debian / Ubuntu / CentOS Linux on top of Windows inside Virtualbox Virtual Machine and you're wondering how to Share files between Windows Host Operating System and Guest Operating System (Linux), here is how:

1. First make sure Virtualbox guest additions are installed

Besides installing Virtualbox guest additions which will enable you to resize VBox Window / enable copy paste between guest and host OS it is useful to have also Virtualbox extension packs which allows your Virtual Machine to be accessed remote via Remote Desktop Protocol (RDP) – the so called VRDP

2. From Virtualbox VM select folder on Windows hsot which will be shared

Selection of which Win folder to mount in Vbox is done via Virtualbox menus:
 

Machine -> Settings -> Shared Folder

virtualbox-windows-linux-guest-OS-how-to-shared_folder-screenshot2

virtualbox-windows-linux-guest-OS-how-to-shared_folder-screenshot

3. Launch Linux Virtual Machine and use mount command to mount shared folder

I like the practice of creating a new folder inside c:UsersgeorgiDownloadsShared_folder

Then fire up gnome-terminal / xterm whatever terminal you like and to mount shared folder inside emulated Linux issue:

mount -t vboxsf -o rw Shared_folder /mnt/Shared_folder/

 

This will mount Shared_folder in rw (read / write) mode, if you prefer to only mount Virtualbox Shared_folder for reading:

mount -t vboxsf -o ro Shared_folder /mnt/Shared_folder/

4. Configure Virtualbox Shared Folder to auto mount in Linux via fstab

As we all know automating mounts in Linux is done by adding line in /etc/fstab to automate Vbox Shared_Folder mount add new line to fstab like:
 

Shared_folder         /mnt/Shared_folder         vboxsf  defaults,rw    0 0

This will auto-mount in vbox shared folder read / write mode, to auto-mount it in read only mode:

Shared_folder         /mnt/Shared_folder         vboxsf  defaults,ro    0 0

  If you added it to /etc/fstab (and you didn't mount Shared Folder manually before), run

mount -a

to make Linux system re-read auto-mounts defined in fstab
 

The new mounted folder will appear in whenever said to be mounted. Enjoy 🙂

 

Install VMWare tools on Debian and Ubuntu Linux – Enable VMWare Fullscreen and copy paste between OS host and Virtual machine

Wednesday, May 28th, 2014

install-vmware-tools-on-debian-gnu-linux-and-ubuntu-howto

If you need to use Virtual Machine to run some testing on heterogenous Operating Systems and you have chosen VMWare as a Virtual Machine. You will soon notice some of Virtual Machines functionality like copy between host operating system and Virtual Machine, true fullscreen mode and most importantly Copy paste between your host operating system and VMWare is not working. I'm not too much into Virtualization these days so for me it was truely shocking that a proprietary software like VMWare, claimed to be the best and most efficient Virtual Machine nowadays is not supporting copy / paste, fullscreen and copy between host and guest OS.  For those arguing why I'm using VMWare at all as it is proprietary and there is already free software Virtual Machines like QEMU and Oracle's VirtualBox its simply because now I have the chance to install and use VMWare 9 Enterprise on my work place at HP with a free Corporate license – in other words I'm using VMWare just for the sake of educating myself and would always recommend VirtualBox for those looking for good substitute free alternative to VMWare.

Before trying out VMWare, I tried Virtualbox to emulate Linux on my HP work PC running Windows with VirtualBox I was having issues with keyboard not working (because of lack of support of USB, no full screen support and lack of copy / paste between OS-es), I've just recently understood this is not because Virtualbox is bad Virtualization solution but because I forgot to install VirtualBox Oracle VM VirtualBox Extension Pack which allows support for USB, enables copy paste and full screen support. The equivalent to Virtualbox Oracle VM VirtualBox in VMWare world is called VMWare-Tools and once the guest operating system is installed inside VMWare VM, its necessary to install vmware-tools to enable better screen resolution and copy paste.
 

In Windows Virtual Machine installation of vmware-tools is pretty straight forward you go through VMWare's menus

 

VM -> Install Vmware-tools

install-vmware-tools-on-linux-guest-host-os-debian-redhat-screenshot

follow the instructions and you're done, however as always installing VMWare-tools on Linux is little bit more complicated you need to run few commands from Linux installed inside the Virtual Machine to install vmware-tools. Here is how vmware-tools is installed on Debian / Ubuntu / Linux Mint and rest of Debian based operating systems:

  1. Install Build essentials and gcc You need to have this installed some developer tools as well as GCC compiler in order for the vmware-tools to compile a special Linux kernel module which enables extra support (integration) between the VMWare VM and the installed inside VM Linux distro

apt-get install --yes build-essential gcc
...

2. Install appropriate Linux headers corresponding to current Linux OS installed kernel

apt-get install --yes linux-headers-$(uname -r)
....

3. Mount CD (Virtual) Content to obtain the vmware-tools version for your Linux

Be sure to have first checked from VMWare menus on menus VM -> Intall Vmware Tools
This step is a little bit strange but just do it without too much questioning …


mount /dev/cdrom /mnt/
umount /media/cdrom0/
mount /media/cdrom
mount /dev/sr0 /mnt/cdrom/
mount /dev/sr0 /mnt/

 

Note that /dev/sr0, might already be mounted and sometimes it might be necessary to unmount it first (don't remember exactly if I unmounted it or not)

4. Copy and Untar VMwareTools-9.2.0-799703.tar.gz

cp -rpf /media/cdrom/VMwareTools-9.2.0-799703.tar.gz /tmp/
cd /tmp/
tar -zxvvf VMwareTools-9.2.0-799703.tar.gz
...

5. Run vmware-tools installer

cd vmware-tools-distrib/
./vmware-install.pl

You will be asked multiple questions you can safely press enter to answer with default settings to all settings, hopefully if all runs okay this will make VMWare Tools installed
 

Creating a new VMware Tools installer database using the tar4 format.
Installing VMware Tools.
In which directory do you want to install the binary files?
[/usr/bin]
What is the directory that contains the init directories (rc0.d/ to rc6.d/)?
[/etc]
What is the directory that contains the init scripts?
[/etc/init.d]
In which directory do you want to install the daemon files?
[/usr/sbin]
In which directory do you want to install the library files?
[/usr/lib/vmware-tools]
The path "/usr/lib/vmware-tools" does not exist currently. This program is
going to create it, including needed parent directories. Is this what you want?
[yes]
In which directory do you want to install the documentation files?
[/usr/share/doc/vmware-tools]
The path "/usr/share/doc/vmware-tools" does not exist currently. This program
is going to create it, including needed parent directories. Is this what you
want? [yes]
The installation of VMware Tools 9.2.0 build-799703 for Linux completed
successfully. You can decide to remove this software from your system at any
time by invoking the following command: "/usr/bin/vmware-uninstall-tools.pl".
Before running VMware Tools for the first time, you need to configure it by
invoking the following command: "/usr/bin/vmware-config-tools.pl". Do you want
this program to invoke the command for you now? [yes]
Initializing…
Making sure services for VMware Tools are stopped.
Stopping VMware Tools services in the virtual machine:
Guest operating system daemon: done
Unmounting HGFS shares: done
Guest filesystem driver: done
[EXPERIMENTAL] The VMware FileSystem Sync Driver (vmsync) is a new feature that creates backups of virtual machines. Please refer to the VMware Knowledge Base for more details on this capability. Do you wish to enable this feature?
[no]
Before you can compile modules, you need to have the following installed…
make
gcc
kernel headers of the running kernel
Searching for GCC…
Detected GCC binary at "/usr/bin/gcc-4.6".
The path "/usr/bin/gcc-4.6" appears to be a valid path to the gcc binary.
Would you like to change it? [no]
Searching for a valid kernel header path…
Detected the kernel headers at "/lib/modules/3.2.0-4-amd64/build/include".
The path "/lib/modules/3.2.0-4-amd64/build/include" appears to be a valid path
to the 3.2.0-4-amd64 kernel headers.
Would you like to change it? [no]
The vmblock enables dragging or copying files between host and guest in a
Fusion or Workstation virtual environment. Do you wish to enable this feature?
[no] yes
make: Leaving directory `/tmp/vmware-root/modules/vmblock-only'

No X install found.
Creating a new initrd boot image for the kernel.
update-initramfs: Generating /boot/initrd.img-3.2.0-4-amd64
Checking acpi hot plug done
Starting VMware Tools services in the virtual machine:
Switching to guest configuration: done
VM communication interface: done
VM communication interface socket family: done
File system sync driver: done
Guest operating system daemon: done
The configuration of VMware Tools 8.6.10 build-913593 for Linux for this
running kernel completed successfully.
You must restart your X session before any mouse or graphics changes take
effect.
You can now run VMware Tools by invoking "/usr/bin/vmware-toolbox-cmd" from the
command line or by invoking "/usr/bin/vmware-toolbox" from the command line
during an X server session.
To enable advanced X features (e.g., guest resolution fit, drag and drop, and
file and text copy/paste), you will need to do one (or more) of the following:
1. Manually start /usr/bin/vmware-user
2. Log out and log back into your desktop session; and,
3. Restart your X session.
Enjoy,
–the VMware team
Found VMware Tools CDROM mounted at /mnt. Ejecting device /dev/sr0 …

.To make sure vmware-tools compiled modules are loaded into Linux kernel inside VM, restart the Virtual Machine. Once Linux boots again and you login to gnome-terminal to check what is vmware-tools status (e.g. if properly loaded) run:

service vmware-tools status
vmtoolsd is running

install-vmware-tools-on-debian-gnu-linux-and-ubuntu-virtual-machine-screenshot

This method of installing works on Debian 7 (Wheezy) but same steps should work on any Ubuntu and rest of Debian derivatives. For Redhat (RPM) based Linux distributions to install vmware-tools after mounting cdrom drive following above instructions you will have an rpm package instead of .tar.gz archive so all you have to do is install the rpm, e.g. launch smth. like:

rpm -Uhv /mnt/cdrom/VMwareTools-9.2.0-799703.i386.rpm
Cheers 😉

Best Windows tools to Test (Benchmark) Hard Drives, SSD Drives and RAID Storage Controllers

Wednesday, April 23rd, 2014

atto-windows-hard-disk-benchmark-freeware-tool-screenshot-check-hard-disk-speed-windows
Disk Benchmarking is very useful for people involved in Graphic Design, 3D modelling, system admins  and anyone willing to squeeze maximum of his PC hardware.

If you want to do some benchmarking on newly built Windows server targetting Hard Disk performance, just bought a new hard SSD (Solid State Drives) and you want to test how well Hard Drive I/O operations behave or you want to see a regular HDD benchmarking of group of MS Windows PCs and plan hardware optiomization, check out ATTO Disk Benchmark.

So why exactly ATTO Benchmark? – Cause it is one of the best Windows Free Benchmark tools on the internet.

ATTO is a widely-accepted Disk Benchmark freeware utility to help measure storage system performance. ATTO though being freeware is among top tools utilized in industry. It is very useful in comparing different Hard Disk vendors speed, measure Windows storage systems performance with various transfer sizes and test lengths for reads and writes.

ATTO Disk Benchmark is used by manufacturers of Hardware RAID controllers, its precious tool to test Windows storage controllers, host bus adapters (HBAs).

Here is ATTO Benchmark tool specifications (quote from their webstie):
 

  • Transfer sizes from 512KB to 8MB
  • Transfer lengths from 64KB to 2GB
  • Support for overlapped I/O
  • Supports a variety of queue depths
  • I/O comparisons with various test patterns
  • Timed mode allows continuous testing
  • Non-destructive performance measurement on formatted drives
  • Transfer sizes from 512KB to 8MB
  • Transfer lengths from 64KB to 2GB
  • Support for overlapped I/O
  • Supports a variety of queue depths
  • I/O comparisons with various test patterns
  • Timed mode allows continuous testing
  • Non-destructive performance measurement on formatted drives
  • – See more at: http://www.attotech.com/disk-benchmark/#sthash.rRlgSTOE.dpuf

Here is mirrored latest version of ATTO Disk for Download. Once you get your HDD statistics you will probably want to compare to other people results. On  TomsHardware's world famous Hardware geek site there are plenty of Hard Drives performance Charts

Of course there are other GUI alternatives to ATTO Benchmark one historically famous is NBench

NBench

nbench_benchmark_windows_hard-drive-cpu-and-memory

Nbench is nice little benchmarking program for Windows NT. Nbench reports the following components of performance:

CPU speed: integer and floating operations/sec
L1 and L2 cache speeds: MB/sec
main memory speed: MB/sec
disk read and write speeds: MB/sec

SMP systems and multi-tasking OS efficiency can be tested using up to 20 separate threads of execution.

For Console Geeks or Windows server admins there are also some ports of famous *NIX Hard Disk Benchmarking tools:

NTiogen

NTiogen benchmark was written by Symbios Logic, It's Windows NT port of their popular UNIX benchmark IOGEN. NTIOGEN is the parent processes that spawns the specified number of IOGEN processes that actually do the I/O.
The program will display as output the number of processes, the average response time, the number of I/O operations per second, and the number of KBytes per second. You can download mirror copy of Ntiogen here


There are plenty of other GUI and Console HDD Benchmarking Win Tools, i.e.:

IOMeter (ex-developed by Intel and now abandoned available as open source available on SourceForge)

iometer-benchmark-disk-storage-speed-windows
 

Bench32 – Comprehensive benchmark that measures overall system performance under Windows NT or Windows 95, now obsolete not developed anymore abandoned by producer company.

ThreadMark32 – capable of bench (ex developed and supported by ADAPTEC) but also already unsupported

IOZone – filesystem benchmark tool. The benchmark generates and measures a variety of file operations. Iozone has been ported to many machines and runs under many operating systems.
 

N! B! Important note to make here is above suggested tools will provide you more realistic results than the proprietary vendor tools shipped by your hardware vendor. Using proprietary software produced by a single vendor makes it impossible to analyze and compare different hardwares, above HDD benchmarking tools are for "open systems", e.g. nomatter what the hardware producer is produced results can be checked against each other.
Another thing to consider is even though if you use any of above tools to test and compare two storage devices still results will be partially imaginary, its always best to conduct tests in Real Working Application Environments. If you're planning to launch a new services structure always test it first and don't rely on preliminary returned soft benchmarks.

if you know some other useful benchmarking software i'm missing please share.

Start Stop Restart Microsoft IIS Webserver from command line and GUI

Thursday, April 17th, 2014

start-stop-restart-microsoft-iis-howto-iis-server-logo
For a decomissioning project just recently I had the task to stop Microsoft IIS  on Windows Server system.
If you have been into security for a while you know well how many vulnerabilities Microsoft (Internet Information Server) Webserver used to be. Nowadays things with IIS are better but anyways it is better not to use it if possible …

Nomatter what the rason if you need to make IIS stop serving web pages here is how to do it via command line:

At Windows Command Prompt, type:

net stop WAS

If the command returns error message to stop it type:

net stop W3SVC

stop-microsoft-IIS-webservice
Just in case you have to start it again run:

net start W3SVC

start-restart-IIS-webserver-screenshot

For those who prefer to do it from GUI interface, launch services.msc command from Windows Run:

> services.msc

services-msc-stop-microsoft-iis-webserver

In list of services lookup for
IIS Admin Service and HTTP SSL
a) (Click over it with right mouse button -> Properties)
b) Set Startup type to Manual
c) Click Stop Button

You're done now IIS is stopped to make sure it is stopped you can run from cmd.exe:

telnet localhost 80

when not working you should get 'Could not open connection to the host. on port 80: Connection failed' like shown up in screenshot.

MySQL: How to check user privileges and allowed hosts to connect with mysql cli

Wednesday, April 2nd, 2014

how-to-check-user-privileges-and-allowed-hosts-to-connect-with-mysql-cli

On a project there are some issues with root admin user unable to access the server from remote host and the most probable reason was there is no access to the server from that host thus it was necessary check mysql root user privilegse and allowed hosts to connect, here SQL query to do it:
 

mysql> select * from `user` where  user like 'root%';
+——————————–+——+——————————————-+————-+————-+————-+————-+————-+———–+————-+—————+————–+———–+————+—————–+————+————+————–+————+———————–+——————+————–+—————–+——————+——————+—————-+———————+——————–+——————+————+————–+———-+————+————-+————–+—————+————-+—————–+———————-+
| Host                           | User | Password                                  | Select_priv | Insert_priv | Update_priv | Delete_priv | Create_priv | Drop_priv | Reload_priv | Shutdown_priv | Process_priv | File_priv | Grant_priv | References_priv | Index_priv | Alter_priv | Show_db_priv | Super_priv | Create_tmp_table_priv | Lock_tables_priv | Execute_priv | Repl_slave_priv | Repl_client_priv | Create_view_priv | Show_view_priv | Create_routine_priv | Alter_routine_priv | Create_user_priv | Event_priv | Trigger_priv | ssl_type | ssl_cipher | x509_issuer | x509_subject | max_questions | max_updates | max_connections | max_user_connections |
+——————————–+——+——————————————-+————-+————-+————-+————-+————-+———–+————-+—————+————–+———–+————+—————–+————+————+————–+————+———————–+——————+————–+—————–+——————+——————+—————-+———————+——————–+——————+————+————–+———-+————+————-+————–+—————+————-+—————–+———————-+
| localhost                      | root | *5A07790DCF43AC89820F93CAF7B03DE3F43A10D9 | Y           | Y           | Y           | Y           | Y           | Y         | Y           | Y             | Y            | Y         | Y          | Y               | Y          | Y          | Y            | Y          | Y                     | Y                | Y            | Y               | Y                | Y                | Y              | Y                   | Y                  | Y                | Y          | Y            |          |            |             |              |             0 |           0 |               0 |                    0 |
| server737                        | root | *5A07790DCF43AC89820F93CAF7B03DE3F43A10D9 | Y           | Y           | Y           | Y           | Y           | Y         | Y           | Y             | Y            | Y         | Y          | Y               | Y          | Y          | Y            | Y          | Y                     | Y                | Y            | Y               | Y                | Y                | Y              | Y                   | Y                  | Y                | Y          | Y            |          |            |             |              |             0 |           0 |               0 |                    0 |
| 127.0.0.1                      | root | *5A07790DCF43AC89820F93CAF7B03DE3F43A10D9 | Y           | Y           | Y           | Y           | Y           | Y         | Y           | Y             | Y            | Y         | Y          | Y               | Y          | Y          | Y            | Y          | Y                     | Y                | Y            | Y               | Y                | Y                | Y              | Y                   | Y                  | Y                | Y          | Y            |          |            |             |              |             0 |           0 |               0 |                    0 |
| server737.server.myhost.net | root | *5A07790DCF43FC89820A93CAF7B03DE3F43A10D9 | Y           | Y           | Y           | Y           | Y           | Y         | Y           | Y             | Y            | Y         | Y          | Y               | Y          | Y          | Y            | Y          | Y                     | Y                | Y            | Y               | Y                | Y                | Y              | Y                   | Y                  | Y                | Y          | Y            |          |            |             |              |             0 |           0 |               0 |                    0 |
| server4586                        | root | *5A07790DCF43AC89820F93CAF7B03DE3F43A10D9 | N           | N           | N           | N           | N           | N         | N           | N             | N            | N         | N          | N               | N          | N          | N            | N          | N                     | N                | N            | N               | N                | N                | N              | N                   | N                  | N                | N          | N            |          |            |             |              |             0 |           0 |               0 |                    0 |
| server4586.myhost.net              | root | *5A07790DCF43AC89820F93CAF7B03DE3F43A10D9 | N           | N           | N           | N           | N           | N         | N           | N             | N            | N         | N          | N               | N          | N          | N            | N          | N                     | N                | N            | N               | N                | N                | N              | N                   | N                  | N                | N          | N            |          |            |             |              |             0 |           0 |               0 |                    0 |
+——————————–+——+——————————————-+————-+————-+————-+————-+————-+———–+————-+—————+————–+———–+————+—————–+————+————+————–+————+———————–+——————+————–+—————–+——————+——————+—————-+———————+——————–+——————+————+————–+———-+————+————-+————–+—————+————-+—————–+———————-+
6 rows in set (0.00 sec)

mysql> exit


Here is query explained:

select * from `user` where  user like 'root%'; query means:

select * – show all
from `user` – from user database
where user like 'root%' – where there is match in user column to any string starting with 'root*',
 

How to make SSH tunnel with PuTTY terminal client

Monday, November 18th, 2013

Create-how to make ssh tunnel with Putty on microsoft windows Vista / 7 XP / 2000
Earlier I blogged how to create SSH tunnels on Linux. Another interesting thing is how to make SSH tunnels on Windows. This can be done with multiple SSH clients but probably quickest and most standard way is to do create SSH tunnel with Putty. So why would one want to make SSH tunnel to a Windows host? Lets say your remote server has a port filtered to the Internet but available to a local network to which you don't have direct access, the only way to access the port in question then is to create SSH tunnel between your computer and remote machine on some locally binded port (lets say you need to access port 80 on remote host and you will access it through localhost tunneled through 8080). Very common scenario where tunneling comes handy if you have a Tomcat server behind firewalled DMZ| / load balancer or Reverse Proxy. Usually on well secured networks direct access to Tomcat application server will be disabled to its listen port (lets say 11444). Another important great think of SSH tunnels is all information between Remote server and local PC are transferred in strong SSH crypted form so this adds extra security level to your communication.
Once "real life" case of SSH tunnel is whether you have to deploy an application which fails after deployment with no meaningful message but error is returned by Apache Reverse Proxy. To test directly tomcat best thing is to create SSH tunnel between remote host 11444 and local host through 11444 (or any other port of choice). Other useful case would be if you have to access directly via CLI interface an SQL server lets say MySQL (remote port 3306 filtered) and inaccessible with mysql cli or Oracle DB with Db listener on port 1521 (needed to accessed via sqlplus).

In that case Putty's Tunneling capabilities comes handy especially if you don't have a Linux box at hand.
To create new SSH tunnel in putty to MySQL port 3306 on localhost (3306) – be sure MySQL is not running on localhost 😉
Open Putty Navigate in left pane config bar to:

SSH -> Tunnels

Type in

Source Port

– port on which SSH tunnel will be binded on your Windows (localhost / 127.0.0.1) in this example case 3306.

Then for

Destination
– IP address or host of remote host with number of port to which SSH tunnel will be opened.

N.B. ! in order to make tunneling possible you will need to have opened access to SSH port of remote (Destination) host

make ssh tunnel on Microsoft Windows putty to remote filtered mysql shot

make ssh tunnels on Microsoft windows putty to remote filtered mysql 2 screenshot

open ssh tunnel via WINDOWS port 22 on microsoft windows 7 screenshot

Once click Open you will be prompted for username on remote host in my case to my local router 83.228.93.76. Once you login to remote host open command prompt and try to connect Windows Command prompt Start -> Run (cmd.exe) ;

C:\Users\\hipo> telnet localhost 3306

Connection should be succesful and you from there on assuming you have the MySQL cli version for windows installed you can use to login to remote SQL via SSH tunnel with;

C:\Users\\hipo> mysql -u root -h localhost -p

To later remove existing SSH Tunnel go again to SSH -> Tunnels press on SSH tunnel and choose Remove

Further you can craete multiple SSH tunnels for all services to remote host where access is needed. Important think to remember when creating multiple SSH connections is source port on localhost to remote machine should be unique