If, before reducing disk capacity, you want to know the minimum to which it can be reduced, use the prl_disk_tool resize --info command. For example, if the disk hdd0 of the virtual machine MyVM is emulated by the image /vz/vmprivate/d35d28e5-11f7-4b3f-9065-8fef6178bc5b/harddisk.hdd, run the following command:
# prl_disk_tool resize --info --hdd /vz/vmprivate/d35d28e5-11f7-4b3f-9065- \
8fef6178bc5b/harddisk.hdd
Disk information:
...
Minimum: 2338M
...
