[DRBD-user] Access to the slave node

[Roland Kammerer]

On Thu, Mar 15, 2018 at 10:21:49AM +0000, Ondrej Valousek wrote:
> Hi list,
> 
> When trying to mount the filesystem on the slave node (read-only, I do
> not want to crash the filesystem), I am receiving:
> 
> mount: mount /dev/drbd0 on /brick1 failed: Wrong medium type
> 
> Is it normal? AFAIK it should be OK to mount the filesystem read-only
> on the slave node.  Thanks,

We call them "primary" and "secondary".

That is perfectly expected behavior. Imagine a resync from the primary
that, for some time, makes the secondary inconsistent (see what Lars
already told you). Would not make sense to mount that one... Error codes
are limited, "Wrong medium type" is the one that makes most sense.

For DRBD9 it is possible to mount a secondary RO when there is no
primary.

Regards, rck