Backups with qcow2 enabled

[acebmxer]

@florent

was already enabled. Just not Purge snapshot data when using CBT.

[florent]

@acebmxer did you enabled NBD on the network ( in the pool view ? ) is it a network accessible by the xo ?

[acebmxer]

@florent
Yes...

Think i have solved it / fixed it... I ran the errors though AI and it suggested running a full backup to reset the chain. Full backup was successfull with out issues. Running delta backup now as we speak but looks good so far.

One mistake i made is enabled the purge snapshot with CBT and now vms now failling to full backups.

[Pilow]

@acebmxer I have a new case of managing to force the fell back to full error...
i'll create a new topic for this

in the time being, if you can, do a toolstack restart on your pool when no tasks is ongoing
your backups with NBD could be better (spoiler alert : iptables rules... )

[acebmxer]

@florent

Both full and delta passed...

Full - 2026-04-17T11_32_42.906Z - backup NG.txt
Delta - 2026-04-17T13_26_54.973Z - backup NG.txt

@pilow

I just restarted tool stack on both pool master and second host. Re-edit backup job to remove the purge snapshot with cbt and re-ran a delta backup. Which still fell back to full backup.

[Pilow]

@acebmxer bottom of POOL advanced tab, is BACKUP NETWORK selected on the NBD enabled network accessible by both hosts and XOA ?

[acebmxer]

@Pilow

Was already configured...

Think this is the issue....
Network tab under pool.

Will run another delta once the current one finishes.

Edit - update

Can a warning be made if NBD is not enabled at the pool level? or make the error more clear?

I enabled the nbd at the pool level and ran another delta - 2026-04-17T14_40_39.535Z - backup NG.txt

I Then re-enable the purge snapshot in back up job and ran another delta. 2026-04-17T15_00_40.358Z - backup NG.txt

[Pilow]

@acebmxer so, NBD it was...

holy molly, you have some good network performance !
what kind of SR at source ? and remote at destination ?
what about the PIFs ?

[acebmxer]

@Pilow

Just a little old truenas running on AMD 5900x with 10 Gic nics bound, Unifi Agg switch with 10gb links to hosts.

Storage 5 8tb tohisba drives and two 1tb nvme drives 1 for cache 1 for log vdev.

Backup device is a DS1819+ with 4 12 tb seagate exo drives with 10gb link.

[Pilow]

@acebmxer NFS remotes on the DS1819+ ?

we have iSCSI SR (25Gb mellanox 6 PIFs on hosts to 25Gb MSA2062 SAN dual controller)
our remotes are iSCSI os mounted volumes on MSA SANs, presented as S3 (minio VMs)
using XO PROXIES to offload backups from XOA

we max out a 150/200Mb/s during backups

but we are on VHD VDIs, asking myself if the added backup performance you present could be due to QCOW2 format on source SR ?
will have to try VDIs on such SR to see the diff