Libvirt Snapshot Question

Hi everybody! I'm using a snapshot purely for writes and was wondering if it's possible to clear/empty the snapshot after it reaches a certain size? Created with: virsh snapshot-create-as --disk-only I tried deleting and recreating it but get an error at deletion: virsh snapshot-delete Error: source for disk 'vda' is not a regular file I also tried virsh snapshot-create-as --no-metadata --disk-only But the same error as above pops up when trying to delete. Any ideas?