[Linux-cluster] Online change of fence device options - possible?

[Digimer]

On 23/06/14 02:09 PM, Vasil Valchev wrote:
> Hello,
>
> I have a RHEL 6.5 cluster, using rgmanager.
> The fence devices are fence_ipmilan - fencing through HP iLO4.
>
> The issue is the fence devices weren't configured entirely correct -
> recently after a node failure, the fence agent was returning failures
> (even though it was fencing the node successfully), which apparently can
> be avoided by setting the power_wait option to the fence dev configuration.
>
> My question is - after changing the fence device (I think directly
> through the .conf will be fine?), iterating the config version, and
> syncing the .conf through the cluster software - is something else
> necessary to apply the change (eg. cman reload)?
>
> Will the new fence option be used the next time a fencing action is
> performed?
>
> And lastly can all of this be performed while the cluster and services
> are operational or they have to be stopped/restarted?
>
>
> Regards,
> Vasil

This should be fine. As you said; Update the fence config, increment the 
config_version, save and exit. Run 'ccs_config_validate' and if that 
passes, 'cman_tool version -r'. Note that for this to work, you need to 
have set the 'ricci' user's shell password as well as have the 'ricci' 
and 'modclusterd' daemons running.

Once done, run 'fence_check'[1] to verify that the fence config works 
(it makes a status call to check). If that works, you're good to go.

You can also crontab the fence_check call and have it email you or 
something so that you can catch fence failures earlier.

digimer

1. 
https://alteeve.ca/w/AN!Cluster_Tutorial_2#Using_Fence_check_to_Verify_our_Fencing_Config

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Digimer
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