[DRBD-user] Linstor: confining failure domains to a single back-end device

[Roland Kammerer]

On Wed, Jul 06, 2022 at 02:18:17PM +0200, Daniel Dehennin wrote:
> Daniel Dehennin
> <Daniel.Dehennin at region-academique-bourgogne-franche-comte.fr> writes:
> 
> Hello
> 
> > In the documentation, there is a mention on “confining failure domains
> > to a single back-end device”[1] but I didn't found example of how to do
> > so.
> >
> > Do I understand correctly that it means, on each server:
> >
> >     1 disk == 1 PV == 1 VG == 1 ThinPool == 1 storage-pool
> >
> > ?
> 
> Ok, so I don't understand how to create and use this setup. Does someone
> have any hints?

I'd say your assumption is correct. The "handle" to create actual
resources in LINSTOR then is the resource group/volume group (LINSTOR
rg/vg, not to confuse with LVM). And LINSTOR RGs can have multiple
LINSTOR storage pools. So you always use the same LINSTOR RG, it will
choose one of the SPs and as there is a 1:1 mapping down to 1 physical
disk your failure domain for that resource is that single disk.

Regards, rck