[DRBD-user] DRBD Fencing with RHCS

Lars Ellenberg lars.ellenberg at linbit.com
Fri Jan 4 19:05:04 CET 2008

Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.

On Fri, Jan 04, 2008 at 11:18:15AM -0500, Sean Brown wrote:
> I'm new to setting up clustering and DRBD. We're setting up a HA NFS  
> cluster between 2 nodes, each node is running CentOS 5.1. I have DRBD  
> working between them and RHCS is working with exporting a NFS export  
> backed by GFS. The GFS volume is sitting on drbd0. When everything is  
> running everything is good.

Why do you put GFS below your NFS?
There is no need for it. And it just adds even more complexity.

> However, I simulated a failure by shutting down the node that held the  
> NFS service while a client was writing to it. Now here's what happened:
> Node 1 went down
> NFS Client paused during a write
> NFS Service came up on Node 2
> NFS Client finished write
> NFS Client issued an ls
> NFS Clients ls hung, other processes on the Client were fine
> ls issued on Node 2 against the GFS filesystem, this also hung. All  
> other processes on Node 2 were fine.
> So what happened is DRBD hung without effecting any other operation.  
> When Node 1 was brought back online communications with Node 2 did not  
> resume and a Split-Brain situation occurred.
> Now looking into this I believe that the problem is that the DRBD  
> process/service is not properly fenced, or possibly not fenced at all.  
> Now I see a lot of documentation fencing DRBD with Heartbeat but as I  
> am already using RHCS for other services which depend on DRBD working,  
> is it possible to use RHCS do handle the fencing and heartbeat  
> processes? How would I go about configuring it?
> -Thank you in advance.
> _______________________________________________
> drbd-user mailing list
> drbd-user at lists.linbit.com
> http://lists.linbit.com/mailman/listinfo/drbd-user

: Lars Ellenberg                           http://www.linbit.com :
: DRBD/HA support and consulting             sales at linbit.com :
: LINBIT Information Technologies GmbH      Tel +43-1-8178292-0  :
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