RE: ocfs2/oracleasm on Red Hat 4

From: Matthew Zito <>
Date: Thu, 28 May 2009 13:04:30 -0400
Message-ID: <>

I'm a fan of the, "If it ain't broke..." model of doing things. Periodic updates are fine, but coordinated appropriately, and with consideration. For example, a patch for the "less" command, or a bugfix for "sar" - fine, those changes are isolated and restricted to individual commands.

But anything that touches:
- compiler

  • system libraries
  • kernel

I'm very resistant to applying unless there's a really good reason - like there's a bug I've already hit or believe myself very likely to hit, or a remotely exploitable vulnerability in a fairly open network.

Cause otherwise, you're just fixing bugs you haven't run into yet, which you are unlikely to ever run into - and possibly introducing new bugs with their own set of fun problems.

As far as migrating by gradually adding RHEL5 nodes into the mix, I think that's a supported config, but again, I wouldn't want to be calling Oracle support and explaining that I have two RHEL4 nodes and one RHEL5, and they're all down.


-----Original Message-----

From: QuijadaReina, Julio C [] Sent: Thursday, May 28, 2009 12:59 PM
To: Matthew Zito; Guillermo Alan Bort
Subject: RE: ocfs2/oracleasm on Red Hat 4

Updating the OS kernel has been a best practice for me as I am also doing the Sys admin work. Any specifics as to why you discourage it?

My thought on 'upgrading' was to first add an RHEL5 server to the cluster and then take RHEL4 nodes out.


-----Original Message-----

From: Matthew Zito [] Sent: Thursday, May 28, 2009 12:43 PM
To: QuijadaReina, Julio C; Guillermo Alan Bort Cc:
Subject: RE: ocfs2/oracleasm on Red Hat 4

For sure, both Oracle and Red Hat are encouraging people to go to RHEL5. However, they can encourage all they like, it's still technically a supported OS by both organizations, so they don't have a lot of choice if you press the issue.

If you're looking at upgrading to RHEL5, I guess my question would be - why are you looking at upgrading the kernel version? If it's just as a best practice, I'd discourage you from doing so. If it's for a specific bug, then you may not have any options.

But RHEL4->5 has a number of changes in a number of areas, notably the iSCSI stack, the required kernel parameters for Oracle, a different kernel scheduler model, etc. I'd be very leery of upgrading between major RHELs if possible.

The last option is that you could make your own ASMlib and OCFS2 modules compiled against the updated red hat kernel - probably a shorter turnaround time vs. oracle and you don't have to deal with them. However, does put you in the business of rolling your own software, which some folks are quite resistant to.

-- Received on Thu May 28 2009 - 12:04:30 CDT

Original text of this message