OSX Mavericks Server private/var/folders/ filling up space

Since the upgrade to Mavericks our server is having no end of issues. The major one at the moment is private/var/folders/ filling up with files that never get erased (even after a shutdown)

Only OSX is on this 100Gig partition and quickly more than 70 gig of space disappears... until it gets to zero.

I just took a screenshot with Grandperspective with root permissions which shows on the left the many files created (all in folders). This screenshot was not taken with the hard drive full (I only got to this point once and had to boot with another drive to clear the main drive),

I disabled items launching at login, widgets... the server is barebone.

I also tried checking the hard drive and permissions.

The server has 16 gig of RAM if you wonder.

Needless to say, we never had that issue before upgrading to Mavericks, so I am considering reverting. But I'd prefer fixing this... so any help would be welcome.