Re: [PATCH v4 5/5] iotests: add backup-discard-source

[Vladimir Sementsov-Ogievskiy]

On 11.06.24 20:49, Kevin Wolf wrote:
> Am 13.03.2024 um 16:28 hat Vladimir Sementsov-Ogievskiy geschrieben:
> > Add test for a new backup option: discard-source.
> >
> > Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
> > Reviewed-by: Fiona Ebner <f.ebner@proxmox.com>
> > Tested-by: Fiona Ebner <f.ebner@proxmox.com>
>
> This test fails for me, and it already does so after this commit that
> introduced it. I haven't checked what get_actual_size(), but I'm running
> on XFS, so its preallocation could be causing this. We generally avoid
> checking the number of allocated blocks in image files for this reason.

Hmm right, I see that relying on allocated size is bad thing. Better is to 
check block status, to see how many qcow2 clusters are allocated.

Do we have some qmp command to get such information? The simplest way I see is 
to add dirty to temp block-node, and then check its dirty count through 
query-named-block-nodes

--
Best regards,
Vladimir