To make it clear, you have 20 backup files, it`s not a single backup of 20 VMs. Is that correct?
If so, is that a single chain of 20 backups or several chains? What backup method was used(forward/reverse incremental)?
You can delete the whole chain via GUI
or delete one or several
restore points from the chain.
marius roma wrote:Can I run the backup even if the VMs do not exist anymore?
Yes you can, but only existing VMs will be backed up. Older backups may be deleted by retention though.
If you want to keep VM state of the day when not full but incremental backup had been taken, you can restore the VM, make a new backup/VeeamZIP, delete the VM and old backups.