[ClusterLabs] [ClusterLabs Developers] Fencing with a Quorum Device

[Andrei Borzenkov]

I changed list to users because it is general usage question, not
development topic.

26.08.2020 23:33, Hayden Pfeiffer пишет:
> Hello,
> 
> 
> I am in the process of configuring fencing in an AWS cluster of two
> hosts. I have done so and nodes are correctly fenced when
> communication is broken with ifconfig down tests.
> 

It is highly recommended to test split brain by blocking communication
between nodes (either on external LAN equipment or e.g. using iptables
on host). Setting interface down does not always do what one expects
with corosync.

> 
> However, I would also like to use a quorum device in my setup. I have

Why? What exactly do you need it for?

> configured a third host to act as a tiebreaker, but when I try to
> break communication on one of the two pacemaker hosts, the affected
> host is marked as "unclean" and is not fenced.
> 

It is unclear what you did. Do you corosync-qdevice? Post actual
configuration (corosync.conf and pacemaker config) and your
corosync/pacemaker versions.

>  Is it not recommended to use fencing devices and a quorum device in
> the same cluster? I cannot find any documentation relating to this
> issue. Thanks,
> 

corosync-qdevice just affects quorate state of individual nodes. What
happens when node goes out of quorum is determined entirely by pacemaker
configuration. For a long time I have been using two node cluster with
no-quorum-policy=ignore where corosync-device is entirely useless.