How to prevent split brain issue in GCO

[Jomy]

How to prevent split brain issue in GCO.

we have configured 2 cluster in primary and single node cluster in secondary.

It is working fine but.

when ever there is a link issue.Both the sites are going in active state and volumes are mounting on both the sides.

Is there any configuration settings to avoid this.

[Yeying198201]

Do NOT set AutoTakeover attribute on RVGPrimary resource, then even there is a link issue, remote single-node cluster will not mount volumes.

[mikebounds · Accepted solution]

The default for Service group attribute ClusterFailOverPolicy is manual (for global service groups) and the reason for this is that if you have your issue where site is not down and it is link that is down, that the groups on the other cluster to do not take over, so have you changed this setting to Auto?

Also for normal startup, VCS uses Service group attribute Authority, so this prevents any cluster that reboots from starting when it maybe up on the other site.

Mike

[Mike_Magarino]

Jomy,

The configuration suggestions above are a good place to start. VCS has many preventative features that attempt to prevent split brain. Typically, in order for this to happen, all heartbeat links are being lost at the very same time. This is why we recommend more than 1 heartbeat, as it prevents a single point of failure. 

I would suggest investigating why heartbeat links are being lost at the same time.

[RiaanBadenhorst]

Hi,

If you want to run auto then you could configure a steward. See below

https://sort.symantec.com/public/documents/vcs/6.1/aix/productguides/html/vcs_admin/ch16s02s07.htm