[DRBD-user] DRBD 9 auto-promote not changing role to Primary, but is writable

[Roland Kammerer]

On Wed, Nov 13, 2019 at 03:08:37PM -0500, Doug Cahill wrote:
> I'm configuring a two node setup with drbd 9.0.20-1 on CentOS 7
> (3.10.0-957.1.3.el7.x86_64) with a single resource backed by an SSDs.  I've
> explicitly enabled auto-promote in my resource configuration to use this
> feature.
> 
> The drbd device is being used in a single-primary configuration as a zpool
> SLOG device.  The zpool is only ever imported on one node at a time and the
> import is successful during cluster failover events between nodes.  I
> confirmed through zdb that the zpool includes the configured drbd device
> path.
> 
> My concern is that the drbdadm status output shows the Role of the drbd
> resource as "Secondary" on both sides.  The documentations reads that the
> drbd resource will be auto promoted to primary when it is opened for
> writing.

But also demoted when closed (don't know if this happens in your
scenario).

> drbdadm status
> r0 role:Secondary
>   disk:UpToDate
>   dccdx0 role:Secondary
>     peer-disk:UpToDate

Maybe it is closed and demoted again and you look at it at the wrong
points in time? Better look into the syslog for role changes, or monitor
with "drbdsetup events2 r0". Do you see switches to Primary there?

Best, rck