[Ocfs2-users] One node, two clusters?

[Sunil Mushran]

On 12/22/2011 10:39 AM, Kushnir, Michael (NIH/NLM/LHC) [C] wrote:
> Is there a separate DLM instance for each ocfs2 volume?
>
> I have two "sub-clusters" in the same cluster... A 10 node Hadoop cluster sharing a SATA RAID10 and a Two node web server cluster sharing a SSD RAID0. One server mounts both volumes to move data between as necessary.
>
> This morning I got the following error (see end of message), and all nodes lost access to all storage. I'm trying to mitigate risk of this happening again.
>
> My hadoop nodes are used to generate search engine indexes, so they can go down. But my web servers provide the search engine service so I need them to not be tied to my hadoop nodes. I just feel safer that way. At the same time,  I need a "bridge" node to move data between the two. I can do it via NFS or SCP, but I figured it'd be worth while to ask if one node can be in two different clusters.
>
> Dec 22 09:15:42 lhce-imed-web1 kernel: (updatedb,1832,1):dlm_get_lock_resource:898 042F68B6AF134E5C9A9EDF4D7BD7BE99:O0000000000000013d2ef9400000000: at least one node (11) to recover before lock mastery can begin
>

You should add ocfs2 to PRUNEFS in /etc/updatedb.conf. updatedb generates
a lot of io and network traffic. And it will happen around the same time on all nodes.

Yes, each volume has a different dlm domain (instance).