[Gluster-users] UCARP with NFS

[Whit Blauvelt]

On Thu, Sep 08, 2011 at 01:02:41PM +0000, anthony garnier wrote:

> I got a client mounted on the VIP, when the Master fall, the client switch
> automaticaly on the Slave with almost no delay, it works like a charm. But when
> the Master come back up, the mount point on the client freeze.
> I've done a monitoring with tcpdump, when the master came up, the client send
> paquets on the master but the master seems to not establish the TCP connection.

Anthony,

Your UCARP command line choices and scripts would be worth looking at here.
There are different UCARP behavior options for when the master comes back
up. If the initial failover works fine, it may be that you'll have better
results if you don't have a preferred master. That is, you can either have
UCARP set so that the slave relinquishes the IP back to the master when the
master comes back up, or you can have UCARP set so that the slave becomes
the new master, until such time as the new master goes down, in which case
the former master becomes master again.

If you're doing it the first way, there may be a brief overlap, where both
systems claim the VIP. That may be where your mount is failing. By doing it
the second way, where the VIP is held by whichever system has it until that
system actually goes down, there's no overlap. There shouldn't be a reason,
in the Gluster context, to care which system is master, is there?

Whit