[Linux-cluster] Redhat without qdisk

Anderson, John(Patni) John.Anderson4 at weyerhaeuser.com
Thu Apr 12 15:12:31 UTC 2012

I don't normally chime in, but running RHEL on a two node cluster we have found that the only way to ensure fencing works properly is with a 2gb qdisk.  The option you were told works correctly less than 50% of the time as both attempt to fence the other.  We set up a delay on the passive node so if the active node gets in trouble the qdisk switches to the passive at the end of the delay, and the fencing takes place.  The process takes about 5 minutes or so.

John A.

From: linux-cluster-bounces at redhat.com [mailto:linux-cluster-bounces at redhat.com] On Behalf Of Daniel Bourque
Sent: Thursday, April 12, 2012 7:47 AM
To: linux clustering
Subject: Re: [Linux-cluster] Redhat without qdisk

A qdisk is just another way to maintain quorum in cluster. there is a special two node cluster mode designed to allow for quorum to be maintained by the surviving node.

<cman two_node="1" expected_votes="1">

But it's not very clear to me what happens with fencing if both nodes get partitioned on the network. Do they both try to fence each other off ?


From: linux-cluster-bounces at redhat.com [linux-cluster-bounces at redhat.com] on behalf of emmanuel segura [emi2fast at gmail.com]
Sent: Thursday, April 12, 2012 9:25 AM
To: linux clustering
Subject: [Linux-cluster] Redhat without qdisk
Hello all List

I have a big question about qdisk in a two cluster

one of out clients has too many cluster in two nodes configuration and one RedHat technical came to us and said that there is no need to use the qdisk

I would to know if this is true

I really think it's a bad idea

esta es mi vida e me la vivo hasta que dios quiera
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