Oracle 9i RAC with MC/SG - possibility to run on single node

[Rasheed Tamton]

We have a rp7400 (N4000) box with HP-UX 11.00, MC/SG 11.13 and Oracle 9i (9.0.1.2.0) RAC on a two node cluster environment. We have a big problem on getting enough downtime for sysadm activities. Right now we are on a process of migrating the storage to EMC and need to install two HBAs. The system has many raw devices for database (around 150 LVs) and the migration will be a headache plus the downtime constraints.


We are considering a plan as to whether or not we can run the system on a single node and
power off
install the HBAs and drivers and
bring back the node and switch the database to the other node
and do the same activities on the other node.

Can anyone please advise me what are the correct steps to do these activites. Our dba is not that experienced with Oracle RAC so that I am also a bit restless to do the said tasks. I would also like to know how we can stop the Oracle RAC cluster and run it on a single node before I do anything on MC/SG side.

Thank you
Rasheed

[Hein van den Heuvel · Accepted solution]

Well yes, the whole point of RAC is that you can keep on computing, transparently, as long as there is at least one node remaining. It will be able to do so, even if you yank away a node unacnnouced, but in your case you can nicely shut down the instance on the node-to-be-upgraded.

You do want to make sure that the node-to-be-upgraded does not try to restart the instance right-away, so check your startup environment / oratab and change temporarely.
When you bring up the node after the changes you want to be sure that the LV's for oracle are still visible. Maybe device names changed?!

Once you assured yourself that the DB instance has a reasonable chance to start back up, give it a whirl! Once back up succesfully, it would be time to bring down the other node and upgrade it.

Be sure to spend some quality time with the Oracle RAC and and general Oracle management documentation to become more confident about the steps.

Also, work with EMC! Did they sell you just a collection of hardware or 'a storage solution'. If they sold you a 'solution' then let them play a major role! They have been there (one hopes). They know what to do (one hopes). If they fail to support the transition, then I would bring the whole update in question towards your management.
(Heck, if they can not help in a controlled transition, how will they help if you get in unexpected trouble at some point. But I'sure they can and will help).

hth,
Hein.