[Lustre-discuss] Question on setting up fail-over

[David Noriega]

Some info:
MDS/MGS 192.168.5.104
Passive failover MDS/MGS 192.168.5.105
OSS1 192.168.5.100
OSS2 192.168.5.101

I've got some more questions about setting up failover. Besides having
heartbeat setup, what about using tunefs.lustre to set options?

On the MDS/MGS I set the following options
tunefs.lustre --failnode=192.168.5.105 /dev/lustre-mdt-dg/lv1
Heartbeat works just fine, can mount on the primary node and then
failover to the other and back.

Now on the OSSs things get a bit more confusing. Reading these two blog posts:
http://mergingbusinessandit.blogspot.com/2008/12/implementing-lustre-failover.html
http://jermen.posterous.com/lustre-mds-failover

>From these I tried these options:
tunefs.lustre --erase-params --mgsnode=192.168.5.104 at tcp0
--mgsnode=192.168.5.105 at tcp0 --failover=192.168.5.101 at tcp0
-write-params /dev/lustre-ost1-dg1/lv1

I ran that for all for OSTs, changing the failover option on the last
two OSTs to point OSS1 while the first two point to OST2.

My understanding is that you mount the OSTs first, then the MDS, but
the OSTs are failing to mount. Are all these options needed? Or is
simply specifying the primary MDS is enough for it to find out about
the second MDS?

David

On Mon, Aug 16, 2010 at 2:14 PM, Kevin Van Maren
<kevin.van.maren at oracle.com> wrote:
> David Noriega wrote:
>>
>> Ok I've gotten heartbeat setup with the two OSSs, but I do have a
>> question that isn't stated in the documentation. Shouldn't the lustre
>> mounts be removed from fstab once they are given to heartbeat since
>> when it comes online, it will mount the resources, correct?
>>
>> David
>>
>
>
> Yes: on the servers, they must be not there or "noauto".  Once you start
> running heartbeat,
> you have given control of the resource away, and must not mount/umount it
> yourself
> (unless you stop heartbeat on both nodes in the HA pair to get control
> back).
>
> Kevin
>
>



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