[Lustre-discuss] Lustre failover of MGS

[neil rutter]

hi there,

i have an issue with failover of the MGS device within my cluster.

i'm building a simple lustre environment; just one lustre file system 
(testfs) ...

i have a two node cluster for my MGS/MDT; this is for an active/passive 
config with the MGS and MDT on different devices and mounted separately 
(not co-locating).

i have a two node cluster for my OSTs, in an active/active config in 
that the first OST is on node one and the second OST is on node two.

if i have the above, then heartbeat is happy with the OSTs and the MDT 
mountpoints being mounted on either node in the cluster. the MGS however 
is not. i get the following message when it tries to mount on the 
alternative node:

---8<---
mount.lustre: mount /dev/sdb at /lustre/testfs/mgs failed: Invalid argument
This may have multiple causes.
Are the mount options correct?
Check the syslog for more info.
---8<---

i've noticed that if i consolidate and have my MGS and MDT on the same 
device/mountpoint on the MDS cluster nodes, all is well and the file 
system mounts on the alternative node perfectly.

any ideas?

i have ensured i created the file systems with --failnode and --mgsnode= 
for each MDS server, but no joy.

i can see in a previous post to lustre-discuss someone having a similar, 
if not the same issue:

http://lists.lustre.org/pipermail/lustre-discuss/2008-September/008634.html

cheers