manbackupReviewed July 15, 2026
External snapshots and block jobs
An external snapshot pivots writes into a new overlay so the previous layer can be copied consistently. It is a mechanism, not a complete backup policy. Inspect before snapshot Quiesce boundary Use the QEMU guest agent a
snapshotblockcommitblockpullqcow2
An external snapshot pivots writes into a new overlay so the previous layer can be copied consistently. It is a mechanism, not a complete backup policy.
Inspect before snapshot
BASH
virsh domblklist guest01 --details
virsh domfsinfo guest01
virsh snapshot-list guest01 --treeQuiesce boundary
Use the QEMU guest agent and application-aware procedures when crash consistency is insufficient. Database consistency may require native backup integration even when filesystems are frozen.
Watch block operations
BASH
virsh blockjob guest01 vda --info
virsh domjobinfo guest01
qemu-img info --backing-chain /var/lib/libvirt/images/guest01.qcow2Never delete a backing file because the filename looks old. Prove the active chain and finish or pivot block jobs correctly first.