[Pacemaker] Fixed! - Re: Problem with dual-PDU fencing node with redundant PSUs

[Andrew Beekhof]

On 01/07/2013, at 9:53 PM, Lars Marowsky-Bree <lmb at suse.com> wrote:

> On 2013-07-01T21:37:38, Andrew Beekhof <andrew at beekhof.net> wrote:
> 
>>> 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
> 
> Yeah, I read that.
> 
> But even for 'disk and network' as per your example, handling of the
> "reboot" parameter is broken for levels with multiple devices; one could
> argue that those only make sense with "off", yes, but rebooting via
> mechanism A and then B?

True, you'd not want to use reboot in that case.

> 
>>> And on you to support. ;-)
>> Far easier to support this than extra code to do it automagically.
> 
> Not sure. Essentially it's about expanding the level line for "reboot"
> automatically (into "all off, perhaps some/all on"). Doesn't really
> strike me as so difficult. (For action="off", multiple devices will just
> work fine already.)

Many things are possible but not worth the effort.
Maybe this is one of them, maybe not.

> 
> 
> And I have a comment that, while I don't feel strongly about it, just
> popped into my eyes - the comma separated list is impossible to validate
> via an XML id check. (Because clearly one should only allow devices that
> are actually defined?) Should that be split into multiple elements?

No. RNG can actually validate that.
I may not have implemented it, but I checked its possible before taking that approach.

> 
> 
> Regards,
>    Lars
> 
> -- 
> Architect Storage/HA
> SUSE LINUX Products GmbH, GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer, HRB 21284 (AG Nürnberg)
> "Experience is the name everyone gives to their mistakes." -- Oscar Wilde
> 
> 
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