[ale] Anyone doing Oracle RAC on Linux?

[Jeff Lightner]

Phillip,

Can you elaborate on what issue you saw using redundant paths for raw
devices on RHEL5?

Information gleaned in my install to date:
Well it appears ASMLIB doesn't work with EMC PowerPath as of version 4.4
of the latter.  The release notes for 4.3 talk about how to use it and
the ones in 4.4 say not to use it at all (and remove it).   Since we're
doing RHEL5 we have to use 5.01 and versions after 4.4 don't mention
ASMLIB so my guess is they removed support from 4.4 and all subsequent
versions.

My coworker did an strace and found it had to do with the way the disk
(LUN) responds to one call.  Apparently the multipath pseudo-devices
(LUNs - called emcpower[A-Z] in PowerPath) don't respond the way a
regular disk would so ASMLIB complains that it isn't a "partition".  He
found comments that this was the issue for RDAC as well.

I was going to fall back and use "raw" with udev (had already worked out
udev raw device entries for ocr and votingdisk) but saw your comment
about issues with redundant fibre paths for raw devices.   This wasn't
an issue for ocr/voting disks on RHEL3.  


P.S.  To anyone else who wants to do RAC on RHEL5 I'd recommend going
with OCFS2 out of the gate.  It supports OCR, Voting Disks and the
Database storage.  Apparently raw devices are deprecated as of RHEL5 so
may not be available in future.  I'm just proceeding down this path
because we wanted to play with ASM rather than OCFS2.

-----Original Message-----
From: ale-bounces at ale.org [mailto:ale-bounces at ale.org] On Behalf Of
Philip Rodgers
Sent: Thursday, October 04, 2007 8:41 PM
To: Atlanta Linux Enthusiasts
Subject: Re: [ale] Anyone doing Oracle RAC on Linux?

We have tested Oracle RAC on RHEL 4 and RHEL 5 with ASM (no OCFS)  We
decided to go with RHEL 4 because I never could get the RDAC drivers
for the fiber HBA to work with RHEL 5.  It was a StorageTek 2450 by
the way.  It was very straight forward install on RHEL 4.  There is an
Metalink article concerning install on RHEL 5.  Also the handling of
raw devices is different on RHEL 5 which added to the install
difficulties but it worked great as long as I didn't use redundant
fiber connections.  Perhaps someone could shed some light on what to
do when using RDAC linux on RHEL 5.

On 10/4/07, Jeff Lightner <jlightner at water.com> wrote:
>
>
>
> We currently have Oracle RAC on RHEL3 using OCFS for the datafiles.
There
> is a project underway to do RAC on RHEL5 and we're trying to decide
between
> using ASM and OCFS2.
>
> Is anyone willing to share what they decided if they already did this
on a
> 2.6 kernel based Linux and why they decided it?
> ----------------------------------
> CONFIDENTIALITY NOTICE: This e-mail may contain privileged or
confidential
> information and is for the sole use of the intended recipient(s). If
you are
> not the intended recipient, any disclosure, copying, distribution, or
use of
> the contents of this information is prohibited and may be unlawful. If
you
> have received this electronic transmission in error, please reply
> immediately to the sender that you have received the message in error,
and
> delete it. Thank you.
> ----------------------------------
>
> _______________________________________________
> Ale mailing list
> Ale at ale.org
> http://www.ale.org/mailman/listinfo/ale
>


-- 
Philip Rodgers
philipfromga at gmail.com
"We are spending ourselves into oblivion because we can't tax
ourselves into prosperity"  Herman Cain
_______________________________________________
Ale mailing list
Ale at ale.org
http://www.ale.org/mailman/listinfo/ale
----------------------------------
CONFIDENTIALITY NOTICE: This e-mail may contain privileged or confidential information and is for the sole use of the intended recipient(s). If you are not the intended recipient, any disclosure, copying, distribution, or use of the contents of this information is prohibited and may be unlawful. If you have received this electronic transmission in error, please reply immediately to the sender that you have received the message in error, and delete it. Thank you.
----------------------------------