When you first start up...
How much free disk space do you have in OSX and the Guest VM? How much RAM do you have for both OSX and VM?
What type of Mac do you have?
Also, you can use iStat Pro widget to see your OSX system stats: http://islayer.com/support/?p=24
This may help you too.
I haven't seen this before. Next time it happens, can you try to figure out where the space is going?
These warnings are coming from the host OS (OS X), not inside the VM?
When this happens, can you use Terminal to do "ls -lh /var/vm/" and "df -lh"?
It happens from the host OS - not inside the VM. I have 40gb of free disk space before starting VMware, 3gb RAM and 1.2gb assigned to the VM. I have a MacBook Pro Core 2 Duo (not the latest generation).
The problem does not seem to occur slowly - my free disk space is stable and suddenly it starts dropping like crazy.
I will try to diagnose where the space is going the next time it happens. Hopefully it has nothing to do with VMware.
At first, I thought this was a VM problem but it's not, Check your SQL Server log file. Mine was 37GB on a 3GB database. If this is your problem, you'll need to set SQL Server Recovery to Simple rather than full. There is also a script to shrink your log file.