On 30/06/2013, at 4:48 AM, Lars Marowsky-Bree <l...@suse.com> wrote:
> On 2013-06-29T09:22:20, Andrew Beekhof <and...@beekhof.net> wrote: > >>> This doesn't help people who have dual power rails/PDUs for power >>> redundancy. >> I'm yet to be convinced that having two PDUs is helping those people in the >> first place. >> If it were actually useful, I suspect more than two/three people would have >> asked for it in the last decade. > > I admit that after thinking about it some more, I do see the appeal for > certain configurations. > > Like Digimer wrote, you do need a double failure for this two-layer > fencing mechanism to fail (node burned + one grid down). > > While I personally prefer the self-fence mechanisms, I think this does > make sense for other environments where multiple redundant power > supplies are desired. > > And apparently, this is one of the scenarios for which fence topology > was created and supports multiple devices per level. I'd venture the > opinion that the current implementation of "multiple devices per level" > is broken (since it requires work-arounds like digimer posted). No, it was designed for things like: http://clusterlabs.org/doc/en-US/Pacemaker/1.1-pcs/html/Pacemaker_Explained/_advanced_fencing_configurations.html > > I don't have a very strong opinion, but if this is something RHEL > customers had before, I'd suggest you don't want to force that complex > configuration on them. I don't know what all the location constraints were doing there, but otherwise its no less complex than what they were configuring before. https://access.redhat.com/site/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/Cluster_Administration/s2-dualpower-fence-config-conga-CA.html Setting action= appears to be "normal" in RHCS... I guess thats why they're trying to do it in Pacemaker too. > And on you to support. ;-) Far easier to support this than extra code to do it automagically. _______________________________________________ Pacemaker mailing list: Pacemaker@oss.clusterlabs.org http://oss.clusterlabs.org/mailman/listinfo/pacemaker Project Home: http://www.clusterlabs.org Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf Bugs: http://bugs.clusterlabs.org