PVE 6.3.6: Is there support for multiple disk remapping for online live migrations?

[mpizzolo]

Hello,

Is there support for an online VM live migration using local disks such that a VM with 3 virtual disks, each on a separate non-shared source host local disk can be re-mapped to 3 new local disks on destination host?

The UI seems to only support an atomic move of the entire VM with all disks to either the current layout, or a new layout of only 1 disk. Each Virtual Disk cannot be individually re-mapped. The qm migrate --targetstorage command doesn't seem to indicate it is possible either.

Thanks,

 

[aaron]

If you run the migration from the commandline and you use the --targetstorage option, you can add a mapping, for example:

local-dir:other-dir,local-zfs:local-zfs

 

[mpizzolo]

If you run the migration from the commandline and you use the --targetstorage option, you can add a mapping, for example:

local-dir:other-dir,local-zfs:local-zfs

Hi Aaron,
Thanks for your response. I'm not sure if i'm correctly understanding, or perhaps explaining the situation. What i'm hoping to understand is the following:

Source of Live Migration:
HostA
VMID:100
Disk0: 100GB Local-ZFS PoolA1
Disk1: 200GB Local-ZFS PoolA2
DIsk2: 300GB Local-ZFS PoolA3
Disk3: 400GB Local-ZFS PoolA3

Destination of Live Migration:
HostB
VMID:100
Disk0: 100GB Local-ZFS PoolB1
Disk1: 200GB Local-ZFS PoolB1
Disk2: 300GB Local-ZFS PoolB2
DIsk3: 400GB Local-ZFS PoolB3

Note that the Pools on a virtual disk by virtual disk basis change, and the Pool Names are not the same. So can I map Disk0 to go from PoolA1 --> PoolB1, and DIsk1 to go from PoolA2 --> PoolB1, Disk2 to go from PoolA3-->PoolB2 and Disk3 to go from PoolA3-->PoolB3 all in one Live migration?

Currently I had to move them temporarily to a shared remote Ceph RBD, which allowed the VM to migrate, and then I had to move each disk independently, but would love to skip this if possible. Does the --targetstorage support this multiple, concurrent remapping? if so, can you please provide the syntax? If not, is this something you might consider?

Thanks,
Marco

 

[mpizzolo]

Not sure if anyone else is using local ZFS pools, and if so, whether they also use multiple or not, but would really appreciate understanding whether multiple ZFS pool re-mappings can occur in a live migration. Thanks in advance.

 

[aaron]

If you run it iike that, it will map the local storages:

qm migrate 777 pve2 --targetstorage "local-pve1-a:local-pve2-x,local-pve1-b:local-pve2-y" --with-local-disks  --online

Meaning, disks on local-pve1-a will be placed on local-pve2-x and so on. Obviously, having the same storage names across the cluster makes things easier.

 

[mpizzolo]

Thanks Aaron, really appreciate it. We will test it out next time we need to execute that type of move rather than using an intermediary.