[pve-devel] qemu-kvm online resize with device-backed storage

[Dmitry Petuhov]

Little error. For backing blockdevs qemu cannot set any size. So for 
blockdevs we can just use
     block_resize <dev> 0



12.01.2017 13:40, Dmitry Petuhov wrote:
> Hello.
>
> Looks like PVE's qemu is affected by bug 
> https://bugzilla.redhat.com/show_bug.cgi?id=1070531
>
> I think because of this resize is failing for CEPH with krbd enabled 
> (seen several reports on forum). It also affects my custom DELL plugin.
>
> After backing device is resized, I had error "qmp command 
> 'block_resize' failed - Could not resize: Invalid argument". Manual 
> qmp command also failed:
>     # block_resize drive-scsi1 16492674416640
>     Could not resize: Invalid argument
>
> Surprisingly,
>     # block_resize drive-scsi1 15T
>
> done job.
>
> Just tested (in another machine) with megabytes instead of terabytes, 
> also works OK:
>     # block_resize drive-scsi0 8603566080
>     Could not resize: Invalid argument
>
>     # block_resize drive-scsi0 8205M
>
> So maybe we could do something like
> -    vm_mon_cmd($vmid, "block_resize", device => $deviceid, size => 
> int($size));
> +    vm_mon_cmd($vmid, "block_resize", device => $deviceid, size => 
> ceil($size/1024/1024) . "M");
> in PVE::QemuServer::qemu_block_resize() as workaround?
>
>