[CentOS] RDAC for IBM DS4700

Tue Jul 20 03:20:11 UTC 2010
Jim Perrin <jperrin at gmail.com>

On Mon, Jul 19, 2010 at 11:13 PM, Wahyu Darmawan
<wahyu.darmawan at gmail.com> wrote:
> Hi all,
> I have problem with my servers. I use two of HP Blade Servers and RHEL 4.6
> installed on them, and have IBM DS4700 connected to them.
> In those servers are running RHCS (Red Hat Cluster Suite) with GFS for
> handling Oracle Database.
> Yesterday, I had missing one partition from the storage, suddenly. I called
> IBM and they suggested to use RDAC.

They suggest this because it's what they're familiar with and what
they support.

> The question is, Why should use IBM RDAC for multipath on RHEL 4, and why HP
> Blade + HP EVA Storage don't use any addition plugins software to keep
> server + storage connection?

I'm not sure if the dm-multipath in centos4 is recent enough, but in
centos5 you don't need to use the rdac stuff at all. You can simply
configure the ds4700 using the rhel device-mapper-multipath package
and a couple modifications in the file for wwid and other bits. You
might check into see if this is the case for centos4 as well. We have
a DS4700 as well though with IBM blades, and the mpp (rdac) drivers
are a royal PITA when it comes to updating the kernel. I would look to
see if this blog post helps you ->

During times of universal deceit, telling the truth becomes a revolutionary act.
George Orwell