FAQ Search Today's Posts Mark Forums Read
» Video Reviews

» Linux Archive

Linux-archive is a website aiming to archive linux email lists and to make them easily accessible for linux users/developers.


» Sponsor

» Partners

» Sponsor

Go Back   Linux Archive > Redhat > Cluster Development

 
 
LinkBack Thread Tools
 
Old 10-09-2012, 05:13 PM
Lon Hohberger
 
Default fence daemon problems

On 10/03/2012 12:44 PM, David Teigland wrote:

You might be able to assign
different numbers of votes to reduce the likelihood of everyone loosing
quorum.



(Late to thread - here's an example of what David is talking about):

Node Votes
----- -----
node1 1
node2 2
node3 3
node4 5

Total: 11

Quorate 2-node partition:
- node1 node4 (6 votes / 11)
- node2 node4 (7 / 11)
- node3 node4 (8 / 11)

Inquore 2-node partition:
- node1 node2 (3 / 11)
- node1 node3 (4 / 11)
- node2 node3 (5 / 11)

Effectively, no matter how a 2:2 partition occurs in this configuration,
one partition will always have quorum (and thus be able to fence). Like
a normal 4-node cluster, one node can always fail while the other 3
nodes remain quorate.


-- Lon
 
Old 10-09-2012, 05:14 PM
Lon Hohberger
 
Default fence daemon problems

On 10/03/2012 12:55 PM, Dietmar Maurer wrote:

The intention of that is to prevent an inquorate node/partition from killing a
quorate group of nodes that are running normally. e.g. if a 5 node cluster is
partitioned into 2/3 or 1/4. You don't want the 2 or 1 node group to fence
the 3 or 4 nodes that are fine.


sure, I understand that.


The difficult cases, which I think you're seeing, are partitions where no group
has quorum, e.g. 2/2. In this case we do nothing, and the user has to resolve
it by resetting some of the nodes


The problem with that is that those 'difficult' cases are very likely. For example
a switch reboot results in that state if you do not have redundant network (yes,
I know that this setup is simply wrong).

And things get worse, because it is not possible to reboot such nodes, because
rgmanager shutdown simply hangs. Is there any way to avoid that, so that it is at
least possible to reboot those nodes?



Kill rgmanager and/or 'reboot -fn' ?

I thought inquorate reboots worked - please file a bugzilla.

-- Lon
 

Thread Tools




All times are GMT. The time now is 05:17 AM.

VBulletin, Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Content Relevant URLs by vBSEO ©2007, Crawlability, Inc.
Copyright 2007 - 2008, www.linux-archive.org