Here’s a bummer. Ubuntu’s new default filesystem, EXT4, is not yet supported to shrink the disk size of the Virtual Machine when you would run it through the vCenter (Standalone) Converter.
So far, only EXT2 or EXT3 would be supported to do this.
It’s been shown to be a lack of functionalitity in the VMware Tools, that can not yet read the EXT4 Journaling Filesystem.
Partitions formatted as ext4 might not appear in the Shrink tab of the VMware Tools Properties dialog box. On Linux systems, you display the VMware Tools Properties dialog box with the following command: /usr/bin/vmware-toolbox &. The ext4 file system is the default file system for certain Linux operating systems, such as Ubuntu 9.10.
The solution so far, would be to attempt to convert the EXT4 system to EXT3, and then run a new Converter. Tricky, and have not yet verified or tried it.