KVM: Create Live backups (snapshot-create-as, blockcommit)

Reference document: https://wiki.libvirt.org/page/Live-disk-backup-with-active-blockcommit

• Overview: virsh snapshot-create-as -> cp/rsync -> virsh blockcommit

1. Create an external disk snapshot, specify image destination :

virsh snapshot-create-as --domain VM_TO_BACKUP --diskspec vda,file=/export/images/VM_TO_BACKUP_overlay1.qcow2 --disk-only --atomic

--diskspec To indicate external snapshot and location

--disk-only Do not save memory information

--atomic

2. Take a backup of the original disk: cp or rsync

3. virsh blockcommit VM_TO_BACKUP DEVICE_TARGET --active --verbose --pivot

virsh blockcommit VM_TO_BACKUP vda --active --verbose --pivot (--wait)

Related terms

• virsh domblklist VM_NAME --details
• virsh dumpxml
• virsh vol-list POOL_NAME --details
• Error: unsupported configuration: external snapshot file for disk vda already exists and is not a block device

Activities

1. Review Bash script https://gist.github.com/cabal95/e36c06e716d3328b512b implementing Live Backup and https://gist.github.com/maxim-gorkin/f0e8a2c01a93ca65ad2ad10566a78d72 with logging capabilities, remote destination and rsync usage. (Kvm backup.sh)
2. Review bacula solution: http://www.bacula.lat/kvm-hot-online-virtual-machines-backup-with-bacula-bpipe/?lang=en
3. Review Veritas Netbackup support for RHV
4. View Eric Blacke video: https://www.youtube.com/watch?v=zQK5ANionpU

See also

• Virsh Snapshots: virsh snapshot-create-as, virsh snapshot-info, virsh snapshot-list, virsh blockjob, virsh snapshot-revert (Destructive action), virsh snapshot-delete
• virsh blockcopy, virsh blockjob, virsh blockcommit, virsh domblklist, virsh blockresize, virsh blockpull
• KVM, Installation, QEMU, virsh, virtinst, libguestfs-tools, libvirt, qemu, Red Hat Virtualization (RHV), MacVTap, Virtio, oVirt, KVM services, KVM networking, KVM graphics, CPU, KVM on ARM