WHM/Cpanel Increase The Size Of /tmp (/usr/tmpDSK) Partition


You may have noticed that cPanel’s default partition size for /tmp is
512 MB, which in some cases can be way too small. And sometime you probably get this report email:

Drive Critical: /usr/tmpDSK (/tmp) is 100% full

Although cPanel automatically deletes the unused files, the /tmp would be getting full very quickly on a busy server.

The /tmp partition on cPanel servers, assuming it was the one cPanel created and not one you did yourself, is a file-based partition that can easily be resized.

By default on most servers, /tmp is the temporary dumping place for a lot of things, for example:

  • PHP session files
  • PHP temporary file uploads
  • MySQL temporary files
  • Cache files for certain Apache modules

Most software that uses temporary files or sessions will automatically prefer to use /tmp – this folder is usually set to 777 permissions and therefore writeable by every user on the server. When your /tmp partition fills up, it can cause noticeable problems for your users. If you run a larger server, the /tmp folder can fill up quickly and be very annoying as far as maintenance is concerned. Fortunately there is a very easy way to increase the size of this partition on a standalone server.

  1. Stop MySQL, Apache, and cPanel to prevent writing to the /tmp partition
  2. Copy the contents of /tmp to another location, such as /tmp_backup (cp -rfp /tmp /tmp_backup)
  3. Unmount /tmp. If you’re unable to, you can do an lsof (lsof |grep /tmp) to see what processes are still writing to it, and kill them off. Or do a lazy unmount (umount -l /tmp) .
  4. Delete /usr/tmpDSK (rm -rf /usr/tmpDSK)

Now open /scripts/securetmp and look for this line:

my $tmpdsksize = 512000; # Must be larger than 250000

And change the value of “512000″ to your desired size in MB, and save the
file. Now run the following script to recreate /tmp:

[[email protected] ~]# /scripts/securetmp

This will recreate your /tmp (tmpDSK) partition using the size you specified. While the securetmp script may be overwritten in a cPanel update, the size of /tmp will not be affected one you alter its size.

Originally posted 2016-01-11 05:53:23.