[DRBD-user] linstor-proxmox : online grow of resources

[Robert Altnoeder]

On 09/24/2018 01:03 PM, Julien Escario wrote:
> Hello,
> When trying to resize disk (aka grow only) on Proxmox interface for a
> linstor-backed device, this error is thrown :
> VM 2000 qmp command 'block_resize' failed - Cannot grow device files (500)
>
> BUT resource is effectively growed in linstor and out of sync datas are synced.
> drbdpool/vm-2000-disk-1_00000  27,2G  6,91T  27,2G  -

You can check the size of the DRBD device, /dev/drbd1003 according to
information below, to ensure that the size change was completed by the
LINSTOR & DRBD layers. If the size of the DRBD device has also been
updated, then the problem is somewhere outside of LINSTOR & DRBD.

> At last remark, still for the same resource, ZFS shows much larger volume :
> ╭──────────────────────────────────────────────────────────╮
> ┊ ResourceName   ┊ VolumeNr ┊ VolumeMinor ┊ Size   ┊ State ┊
> ╞┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄┄╡
> ┊ vm-2000-disk-2 ┊ 0        ┊ 1003        ┊ 26 GiB ┊ ok    ┊
> ╰──────────────────────────────────────────────────────────╯
>
> # zfs list drbdpool/vm-2000-disk-2_00000
> NAME                            USED  AVAIL  REFER  MOUNTPOINT
> drbdpool/vm-2000-disk-2_00000  41,6G  6,87T  41,6G  -
>
> This is just after full resync (resource delete/create on this node).
>
> 41GB used for a 26GB volume isn't a bit much ?
> Using zpool history, I can find the used line for this resource :
> 2018-09-24.12:14:43 zfs create -s -V 27268840KB drbdpool/vm-2000-disk-2_00000

27,268,840 kiB is consistent with a 26 GiB DRBD 9 device for 8 peers, so
the reason for the effective size of ~42 GiB would probably be outside
of LINSTOR, unless there was some resize operation in progress that did
not finish.

br,
Robert