[Lustre-discuss] MGS Nids

[Johann Lombardi]

On Thu, May 20, 2010 at 12:46:42PM +0200, leen smit wrote:
> In the new setup I have 4 machines, two MDT's and  two OST's
> We want to use keepalived as a failover mechanism between the two MDT's.
> To keep the MDT's in sync, I'm using a DRBD disk between the two.
> 
> Keepalive uses a VIP in a active/passive state. In a failover situation 
> the VIP gets transferred to the passive one.

Lustre uses stateful client/server connection. You don't need to - and cannot -
use a virtual ip. The lustre protocol already takes care of reconnection &
recovery.

> The problem I'm experiencing, is that I can't seem to get the VIP listed 
> as a NID, thus the OSS can only connect on the real IP, which is 
> unwanted in this situation. Is there an easy way to change the nid on 
> the MGS machine to the VIP?

No, you have to list the nids of all the mgs nodes at mkfs time (i.e.
"--mgsnode=192.168.21.32 at tcp --mgsnode=192.168.21.33 at tcp" in your case).

Johann