upgrade RAC HACMP 4.5 without lots of downtime impossible??

Hi,

Our Unix admin must upgrade our Oracle 9 RAC cluster (AIX 5.1 , HACMP 4.5) to AIX 5.2 and HACMP 5.1.
They tell us that the only way to do this is to switch off one system, upgrade it, upgrade the other and then recombine them to a cluster. That means >4 hours downtime.
The reason is that HACMP won't start if it doesn't see the other node (isn't that one of the basic things it should be capable of...) and RAC wouldn't start without HACMP running.

Our proposal was to just switch of one node (let the RAC DB running), upgrade it, bring down the database, start it with only the upgraded node, upgrade the second node and make it a cluster again.

This isn't possible the Unix admins say. I allmost can't believe that this is true.

A possibility is to install a normal Oracle 9 (non RAC) software branch, start the database with this branch and do a fresh instaal of HACMP on both the node but this looks like turning things a bit up side down?

Any experience? The things I think to read in the redbooks is that it is possible but I would like to give them prove from livesituations from you.

Thanks in advance,

WIjbrand Received on Mon Jul 04 2005 - 06:51:04 CDT