Incus volume storage copy with refresh copies all snapshots when using ZFS

OS: Ubuntu 24.04.1 LTS
Incus: 6.6 installed from Zabbly repo

When using storage / volumes on ZFS, and using copy to another host with refresh, it seams that incus is copying all previous snapshots as well.

Example Commands:

incus storage volume snapshot create example-storage-pool example-volume snap-manual-2024-08-11
incus storage volume snapshot create example-storage-pool example-volume snap-manual-2024-09-11
incus storage volume snapshot create example-storage-pool example-volume snap-manual-2024-10-11

So we have three snapshots separated by a month. With data written between each snapshot. So we copy this to our remote server.

incus storage volume copy example-storage-pool/example-volume remote-incus:example-storage-pool/example-volume --refresh

Its the first copy so lots of data is copied over. All looks well.

However, next month, we issue our snapshot again.

incus storage volume snapshot create example-storage-pool example-volume snap-manual-2024-11-11

incus storage volume copy example-storage-pool/example-volume remote-incus:example-storage-pool/example-volume --refresh

However all previous snapshots are again copied over. Issuing something like ps aux|grep zfs shows that its running zfs send on the old snapshots that were already copied over. My understanding was that this wasn’t supposed to be the behavior and that incus was supposed to only zfs send only sends missing snapshots.

Tests with doing containers backed by zfs, it seams to only send snapshots that are missing, and are very fast to update the remote.

Bug or is my understanding wrong or am I doing something else wrong ?

thanks,

I saw something similar yesterday, can you file a bug at Issues · lxc/incus · GitHub?

Will do. Sorry for delay.

Thank you for replying.

Posted as Issue 1418