@olivierlambert Ah! I didn't have any ISOs connected to the CD drive, but the VM did have quite a few snapshots. I deleted a majority of those (though not even all of them), and it migrated successfully. Thanks!

@planedrop said in Backup / Migration Performance: @KPS Regarding the 2TiB limitation, it'll definitely be nice when we have SMAPIv3 so we can go over this, but it's worth noting that IMO no VMs should be larger than this anyway. Generally speaking if you need that kind of space it'd be better to just use a NAS/iSCSI setup. Something like TrueNAS can delivery that at high speed, and then handle it's own backups and replication of it. I know most probably already know this, and all environments are different (I manage one that requires a 7TiB local disk, at least for the time being, plan is to migrate it to a NAS once the software vendor supports it), but it's worth noting anytime I see the 2TiB limit come up, ideally it should be architected around so the VMs are nimble. I do something similar w/ a pretty massive SMB share and TrueNAS can back this up at whatever speed the WAN can handle, in my case 2 gigabits and it'll maintain that 2 gigabit upload for 8+ hours without slowing down. (and I'm confident even 10 gigabit would be possible with this box) We have 1 exception and that is for Windows file servers which is backing our DFS. Except from those we dont allow VM's larger than 1Tb and if they're that big we do not back them up because it usually breaks and cause all kinds of problems.