Shrink VM disc image

Shrinking is not supported by Proxmox

QEMU is not capable to resize ZFS raw data.

Workaround:

• Shrink disc in guest OS (i.e. using gparted to a bit smaller than desired block device size)
• Change VM disc size. Two ways:
• 1) Clean and safe (but long):
  • Move disk to QCOW2 file on local (dir) storage.
  • Set new disk size

    qemu-img resize --shrink /var/lib/vz/images/703/vm-703-disk-0.qcow2 6G

• 2) Directly change ZFS volume size:
  • zfs set volsize=4GB hddpool/data/vm-123-0
• Edit machine config file and set new size:

  scsi1: rbd:vm-703-disk-2,backup=0,cache=writeback,discard=on,size=6G