The raw VM files are stored in ZFS nested datasets (datapool/vms/{vm1,vm2,...}). A cronjob makes a daily snapshot of the running machines (of the datasets), ma

The raw VM files are stored in ZFS nested datasets (datapool/vms/{vm1,vm2,...}). A cronjob makes a daily snapshot of the running machines (of the datasets), maybe resulting in slightly corrupted VMs, but every now and so often I shut down all vms, make a scripted snapshot of each one and restart them. Then I extract the raw VM files which are in the snapshots onto a HDD and run an md5sum on each of the source and target files and get the results sent to me via email. All of this is automated, except for the shutdown of the VM and the triggering of the snapshot-making script which follows the shutdowns. Apparently there's "domfsfreeze" and "domfsthaw" which could help with the possible corruption of daily snapshots. It's all not really a good or solid strategy, but it's better than nothing.