Re: [ClusterLabs] Antw: Fencing with a 3-node (1 for quorum only) cluster

[Digimer]

On 05/08/16 02:19 AM, Ulrich Windl wrote:
 Dan Swartzendruber  schrieb am 05.08.2016 um 00:56 in
> Nachricht <32eabeb57268bed57081646c77224...@druber.com>:
>> I'm setting up an HA NFS server to serve up storage to a couple of 
>> vsphere hosts.  I have a virtual IP, and it depends on a ZFS resource 
>> agent which imports or exports a pool.  So far, with stonith disabled, 
>> it all works perfectly.  I was dubious about a 2-node solution, so I 
>> created a 3rd node which runs as a virtual machine on one of the hosts.  
>> All it is for is quorum.  So, looking at fencing next.  The primary 
> 
> I wonder what happens if the machine where the VM runs crashes (2 of 3 nodes 
> down).

2 of 3 dead is loss of quorum. Surviving node stops offering cluster
services when it could have otherwise survived. Another (small) benefit
of a 2-node cluster.

-- 
Digimer
Papers and Projects: https://alteeve.ca/w/
What if the cure for cancer is trapped in the mind of a person without
access to education?

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[ClusterLabs] Antw: Fencing with a 3-node (1 for quorum only) cluster

[Ulrich Windl]

>>> Dan Swartzendruber  schrieb am 05.08.2016 um 00:56 in
Nachricht <32eabeb57268bed57081646c77224...@druber.com>:
> I'm setting up an HA NFS server to serve up storage to a couple of 
> vsphere hosts.  I have a virtual IP, and it depends on a ZFS resource 
> agent which imports or exports a pool.  So far, with stonith disabled, 
> it all works perfectly.  I was dubious about a 2-node solution, so I 
> created a 3rd node which runs as a virtual machine on one of the hosts.  
> All it is for is quorum.  So, looking at fencing next.  The primary 

I wonder what happens if the machine where the VM runs crashes (2 of 3 nodes 
down).

> server is a poweredge R905, which has DRAC for fencing.  The backup 
> storage node is a Supermicro X9-SCL-F (with IPMI).  So I would be using 
> the DRAC agent for the former and the ipmilan for the latter?  I was 
> reading about location constraints, where you tell each instance of the 
> fencing agent not to run on the node that would be getting fenced.  So, 
> my first thought was to configure the drac agent and tell it not to 
> fence node 1, and configure the ipmilan agent and tell it not to fence 
> node 2.  The thing is, there is no agent available for the quorum node.  
> Would it make more sense instead to tell the drac agent to only run on 
> node 2, and the ipmilan agent to only run on node 1?  Thanks!
> 
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