live migrate storage to different volume on the same host

[Peter Krempa]

On Sat, Apr 10, 2021 at 01:05:31 +0800, Jing-Wei Su wrote:
> Hello experts,
> 
> I would like to move the qcow2 disk images of a running VM to a
> different storage because of the maintenance of the underlying storage
> on the same host.

You can use the 'virDomainBlockCopy' API to achieve this.

To use it via virsh, the simplest way would be to:

virsh blockcopy $VMNAME $DISKTARGET --dest /path/to/destination
--transient-job --pivot (--verbose)

($DISKTARGET is 'vda' for example)

In case you need a more complicated description of the target of the
copy such as a network storage target you can also use the --xml option
to use a XML description of the target.

> I found the live migration is not allowable on the same host using
> virsh. Is there any suggestion or better practices for this?

Full migration would also try to move the qemu process which is not
required in your case.