[solved] MYSQL Can't start server: can't create PID file: No space left on device

Hi all dear friends of HTV, today i will explain how to fix a bug that affects MySQL server running on a Centos 5.0 Box.

The error in the /var/log/mysqld is :

Can't start server: can't create PID file: No space left on device MYSQL

If your MySQL can't restart and the /var/log/mysqld log show you this message, well, most probably you finished your partition space available.

To solve this issue you have to do the following steps:

1) check your partitions with the command:

df -h

this command will output your partitions conf:

Filesystem            Size  Used Avail Use% Mounted on
/dev/sda2              58G   53G   0  100% //dev/sda1              99M   12M   83M  13% /boot
/dev/sda2              58G   13G   42G  24% /media/sda2


Please notice that the full size of /dev/sda2 partition is 58GB, the used space is 53GB and the available once is 0 (100% use).


2) Now that we are aware of this we have to find the files (often they are huge log files) that fill our partition. So we could take a look in the /var directory or /tmp directory to find and move some of them via rsync into another partition or we could free some space deleting older logs and files not needed. (Be carefully when you are doing that).
To find big files over your system you could execute this command via ssh


 du -h --max-depth=3 /* > mybigfiles.txt


This command will write in the file all the output of the command du -h -max-depth=3 in the file named mybigfiles.txt all showing all the dirs in the system with theirs current size.

Navigating through this file you could find which directories are the biggest ones and after that you have to clean them before restarting MySQL server.

First of all do this command via cmd line:

yum clean all

To empty cached sources and packages in your RH distro.

Then if you would like to remove, for example, all the log files in a dir older then 3 days you have to execute the command :

find /var/log/mydirectorywithbigfiles -type f -mtime +3 -exec rm {}

or use this bash script

#!/bin/bash

find /var/log/mydirectorywithbigfiles -type f -mtime +3 -exec rm {} \;

  

that use a combo of find command and -exec rm {} that removes all the files inside that dir.

After that please execute again the command to check if you freed up some disk space.


df -h

Filesystem            Size  Used Avail Use% Mounted on
/dev/sda2              58G   13G   42G  24% //dev/sda1              99M   12M   83M  13% /boot
/dev/sda2              58G   13G   42G  24% /media/sda2



Once finished, please restart your Mysqld daemon, via /etc/init.d/mysqld start.


Leave a comment if you liked this guide.


HTV

Add a custom script as a daemon on reboot of a redhat centos server

To enable a custom script in a redhat centos server linux box you have to follow those simple steps.
This is useful when you have to start a server process that don't return anything..
One example is openoffice server aka (soffice).
Suppose you have two files.
The first file A call the second file named B-so
The file A contains a code like this

# Source function library.
. /etc/rc.d/init.d/functions

[ -f /usr/local/sbin/B-so ] || exit 0


prog="B-so"
start() {
echo -n $"Starting $prog: "
daemon /usr/local/sbin/B-so 1> /dev/null 2> /dev/null &
RETVAL=$?
echo
return $RETVAL
}

stop() {
if test "x`ps aux | grep B-so | grep -v grep | awk '{ print $2 }'`" != x; then
echo -n $"Stopping $prog: "
killproc B-so
killall processname
echo
fi
RETVAL=$?
return $RETVAL
}

case "$1" in
start)
start
;;

stop)
stop
;;

status)
status B-so
;;

restart)
stop
start
;;

*)
echo $"Usage: $0 {start|stop|restart|status}"
exit 1

esac

exit $RETVAL


Copy the file A in the directory /etc/init.d/

Copy the second file B.so in the dir /usr/local/sbin/
The file B-so contains a code like this:


. /etc/rc.d/init.d/functions

LOG="/root/mail2fax/log/safe-B.log"


while :
do
...done some stuff ...
done


After that you have to add a line with the path to the service to start in the /etc/rc.local.

Check if permissions on those two files are set on 0755,then you could reboot your server and verify if the service start successfully.

img credits wmliu

[Solved] DocumentConverter.py via PHP on Linux RedHat Centos

This is a guide to fix the use of PYODConverter on linux RedHat Centos 5 box users.
If you wanna use DocumentConverter.py written by artofsolving, you have to follow those steps.

1)Install openoffice on your linux box or verify installation through commands:
Install Packages

yum install openoffice.org-xxx.

Check Packages

yum list | grep "openoffice".


2)Install python-uno bridge

3)Download DocumentConverter.py

4)Add the following line below "import uno"...

import sys
sys.path.append("/usr/lib/openoffice.org/program")


5)Run openoffice like a service with -headless and -nofirtstartwizard options.


/usr/lib/openoffice.org/program/soffice -nologo -nofirststartwizard -headless -norestore -invisible "-accept=socket,host=localhost,port=8100,tcpNoDelay=1;urp;"




The port 8100 must be the same for client and server obviously.


If you execute this php code



$cmd = "/usr/bin/python /var/www/html/DocumentConverter.py inputfile $outputfile.pdf 2>&1 | tee /var/www/html/mylog.txt"; // tee used to log output and errors of cmd
exec($cmd, $results);
printf("Exec Output: {".print_r($results).";}\n"); //print results of exec command


you'll probably get this error:


[Java framework] Error in function createSettingsDocument (elements.cxx).javaldx failed!
And other permissions problems on tmp dirs.

To solve this, simply add into your php script those lines of code

if (!file_exists("/tmp/ooohomedir"))
{
mkdir("/tmp/ooohomedir");
chmod("/tmp/ooohomedir", 0777);
}
putenv("HOME=/tmp/ooohomedir");



If you have another workaround about this please leave a comment below.
C u.