RE: RAC w/ASM - scanorder with EMC powerpath devices

  • From: "Kevin Closson" <kevinc@xxxxxxxxxxxxx>
  • To: <oracle-l@xxxxxxxxxxxxx>
  • Date: Sun, 23 Jul 2006 13:52:57 -0700

Using a "loosely coupled" cluster like this, bad things
happen...I'd say you should be overjoyed your
entire ASM raw disk space didn't get corrupted.
 
I don't wish bad things on people, for sure, but
this is a mild trainwreck compared to others
I've heard of.
 


________________________________

        From: oracle-l-bounce@xxxxxxxxxxxxx
[mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of Steve Perry
        Sent: Sunday, July 23, 2006 12:49 PM
        To: oracle-l@xxxxxxxxxxxxx Freelists
        Subject: RAC w/ASM - scanorder with EMC powerpath devices
        
        
        for those of you running ASM on RHEL4, you might want to make
sure the scanorder is setup properly in /etc/sysconfig/oracleasm. 

        I got called last week about a node being down on 2-node RAC SE
with ASM.
        node 1 was crashed and node 2 was running.
        the error in the logs said it had a corrupt control file. After
looking into it a little bit more, I saw there was emergency SAN
maintenance done around the same time.
        suspicious, I kept looking around. It shouldn't have been a
problem because we have redundancy built into it (dual HBAs, multiple
paths to the EMC array...)
        ASM was up and running, but trying to start the instance
generated a bunch of errors.
        Oracle said the controlfile was gone, but I didn't believe it
because node2 was working. 
        the SAN admin and myself were talking about and I mentioned that
we point to the pseudo device and not the real paths. 
        That made want to go and double check. I looked at node 2 and it
was using "emcpowera1" for asm.
        I went over to node1 (crashed node) and it was using "sdb1" (
which was a path SPB that was replaced during maintenance).
        I looked at the oracleasm_scanorder and it was missing from
node1. node2 had it set to "emcpower sd".
        made the additional change and rebooted it. asm used it, but the
cluster wouldn't come up. Oracle said it was in a split brain condition.
I rebooted both nodes, ASM chose the emc power devices for both and both
instances came up - no corrupt controlfile.
        found much information on ASM and rhel3.

Other related posts: