Just to give some follow up in case there are others experiencing the same thing:

- I've deleted the ps.db database
- The next morning a new database was created and everything is working just fine now

We are still running the 5.2 version.

Thank you Tim for your support.

Hello Tim,

Thank you for your fast reply.
We are indeed running an older version, that could be the cause.

For now, I have temporarily removed the database. Default behavior should be that it creates a new database, so I'm waiting for the results now. Seeing as it is the disk usage app, which we don't frequently use, the impact is pretty small.

The problem was indeed this database taking up almost all the space.
We never really noticed the issue since the progress went pretty slowly, but we will keep it in consideration.

ps.db is the philesight (disk usage app) database. That does seem large considering it's only supposed to store information about directory sizes...

The behaviour was changed in ClearOS 6.2 - which version are you using?
http://tracker.clearfoundation.com/view.php?id=341

You can investigate what taking up drive space with 'du --h --max-depth=1 /'