[SOLVED] Can I copy data from zfs snapshot directly ?

[chengkinhung]

Hi, everybody,

I am tring to migrate one VM from ZFS disk to LVM disk, I can dd clone the full ZFS disk, but this VM is running, so I like to create a snapshot for this ZFS disk first, but I can not find the way to access the device path of this snapshot. Could you please tell us how to copy data from ZFS snapshot or where I can find the snapshot device ? I am using ProxMox 7.4-16 , thanks very much.

 

[chengkinhung]

I find the way to do:

# zfs snapshot pool/vm-100-disk-0@mysns
# zfs set snapdev=visible pool/vm-100-disk-0

after that, the devices of this snapshot will show under /dev/zvol/pool/

# /dev/zvol/pool/vm-100-disk-0@mysns -> ../../zd0
# /dev/zvol/pool/vm-100-disk-0@mysns-part1 -> ../../zd0p1

when completed:

# zfs set snapdev=hidden pool/vm-100-disk-0
# zfs destroy pool/vm-100-disk-0@mysns

 

[LnxBil]

I am tring to migrate one VM from ZFS disk to LVM disk

On the same host? Just do a live migration within the PVE gui.

 

[chengkinhung]

On the same host? Just do a live migration within the PVE gui.

not, to other node without cluster.

 

[LnxBil]

Okay, Backup & restore is also fine ...

 

[chengkinhung]

yes, if dd fail, i will try restoring it form PBS backup.

 

[LnxBil]

yes, if dd fail, i will try restoring it form PBS backup.

Why isn't that your first choice? It's much simpler.

 

[chengkinhung]

because I will still need the snapshot to run rsync later, even when I restored VM from backup, I need to keep the same data till I can run latest rsync. The data is over 2TB, it is not easy.