Re: resizing disk image in a raw file online possible ?

[Nir Soffer]

On Thu, Apr 15, 2021 at 7:13 PM Lentes, Bernd
<bernd.lentes@helmholtz-muenchen.de> wrote:
>
> Hi,
>
> we have several qemu guests running on SLES 12 SP5 and pacemaker and a 
> two-node HA cluster.
> The raw files for the disks for the guests reside on a OCFS2 Volume on a SAN.
> We need to give more storage to a guest (several 100GB).
> Is that online possible ?

Yes, we do this in oVirt for many years.

You need to resize the raw file on storage - this can be done with
truncate:

    truncate -s 500g /path

This does not affect the guest yet, since qemu does not know about the
additional size added.

And then you need to update the qemu about the new size. If you use libvirt
python binding this can be done using:

    flags = libvirt.VIR_DOMAIN_BLOCK_RESIZE_BYTES
    dom.blockResize("sda", 500 * 1024**3, flags=flags)

This should also be possible using virsh.

Nir