No space left on device

Issue :

Following error shows up on the websites which run with mysql.

Warning: session_write_close() [function.session-write-close]: write failed: No
space left on device (28)
in /usr/local/cpanel/base/3rdparty/phpMyAdmin/index.php on line 42

Restarting MySQL fixes the issue temporarily.

Fix :

This usually occurs when /tmp runs out of space. You can check the space by using the following command:

root@server# df -h

Couple of tips to clear some space in /tmp :

1. Check and remove older session files.

root@server# rm -f /tmp/sess*

2. Get rid of semaphores.

root@server# ipcs -s | grep nobody | perl -e ‘while () { @a=split(/\s+/); print `ipcrm sem $a[1]`}’