[ClusterLabs] required nodes for quorum policy

[Andrei Borzenkov]

On Tue, Nov 10, 2015 at 1:20 AM, Radoslaw Garbacz
<radoslaw.garbacz at xtremedatainc.com> wrote:
> Hi,
>
> I have a question regarding the policy to check for cluster quorum for
> corosync+pacemaker.
>
> As far as I know at present it is always (excpected_votes)/2 + 1. Seems like
> "qdiskd" has an option to change it, but it is not clear to me if corosync
> 2.x supports different quorum device.
>
> What are my options if I wanted to configure cluster with a different quorum
> policy (compilation options are acceptable)?
>


If I understand the question correctly and you want cluster to
continue even when less than majority nodes are left - I would say pn
pacemaker level you could simply set no-quorum-policy=ignore and rely
on fencing for resource migration and on corosync 2.x level you could
set last_man_standing so corosync re-evaluates majority every time
nodes come and go (may be with combination with auto_tie_breaker).