VMWare eating up disk space

Hi,

I am running vmware server 1.0.4 on Ubuntu LTS 6.0.6. In a partition mounted as /var/data, I have 3 VMs. The

"df -h" command shows:

Filesystem            Size  Used Avail Use% Mounted on

/dev/mapper/Ubuntu-data  106G  101G     0 100% /var/data

This is weird (incorrect) because the total size is 106G, the used space is 101G but there is no available space

(should have 5G). The used space has been verified to be correct (I used "du" to check each VM's directory).

Originally when I started the VMs the free space shown was about 100M. But as VMWare is running, the space

is eaten up gradually and now it shows no free space.

Any idea? All the free VMs are using pre-allocated vmdk files.

Thanks!