At the moment I am using hosting service from MediaTemple (mt). (mt) is using Plesk Control Panel for its clients. Recently, I have migrated my sites to a higher package of Dedicated-Virtual (dv) package, and I found a strange point. When I checked the free space in the statistic area, it gave me only 12%, like image below

Then, I went to domains section to see which domains own the most space,  the sum of space from all domains is not equal to the above number (of course, just a relative number).

Then I login to root shell, and check the size of each folder by this command:

du -hs [path/to/directory]

And, I found that “/usr/local/psa/PMM/var” occupy more than 5Gb. Then I looked into that folder, and it stored temporary folder, which were used for the last migration process, so just delete it, and now I have more space for my hosting easily.

This technique could be applied for any Plesk based hosting, not only MediaTemple.

Actually, I intended to upgrade my hosting for more space, but I was hesitating because I just need 2 – 3 GBs for my new site, it is not worth to spend more monthly. And now, I have more 5Gb without spending more. So the lesson, is you need to look into some directories such as temp, log … in many cases, they occupy a lot of my bhosting space.