Hello everybody,
I am trying to understand how I can create a setup with two libvirt + kvm + zfs systems, in which I can:
1. Create a domain on sys-a, with storage space on a zfs filesystem. This filesystem stores the qcow2 image, any qcow2 disk snapshots, memory dumps and domain XML definition.
2. Take consistent ZFS snapshots every 15 minutes, and sync them to sys-b. The snapshots will be replicated using syncoid. These will be using scripts to quiesce the VM.
3. Given that most of the disk is synced (at most 15 minutes ago), what are the things I need to ensure (libvirt snapshots, memory snapshot, etc), so that I can do a live migration while copying just the incremental changes since the last snapshot I already transferred?
I was trying to use virsh migrate —copy-storage-inc, however I could not find any working example that would copy just the incremental changes. I could find the theory of the snapshot backing chain, however —copy-storage-inc complains that it cannot replicate while there are snapshots present. (error: Requested operation is not valid: cannot migrate domain with 1 snapshots).
I this scenario possible?
Dan Vatca
