linux vs SAN

[Ed Wilts]

On Wed, Feb 01, 2006 at 10:55:20AM +0200, baran.yurdagul at turkcell.com.tr wrote:
> Veritas volume manager is already installed. 

Right company but wrong product.  Veritas DMP (Dynamic MultiPathing) is
the product you need to configure and since you've got the Volume
Manager and the Veritas cluster suite, you've probably got DMP.

Tom is giving you lots of good advice - he's been there before (as have
I) so learn what you can.

If you fail to configure your multipathing solution correctly, you
could very likely:
1.  Fail to access your storage when an HBA or switch port fails
2.  Corrupt your data

Neither option is a good one.

There are several multipathing options available and they vary depending
on the brand of HBA you're using, the storage array, and the version of
RHEL.

I haven't work with DMP on Linux yet and am getting conflicting reports
from Veritas as to the supportability with our storage arrays (HP EVA).
I hope to start working on a DMP implementation soon if Veritas and HP
can get their acts together.

        .../Ed

> -----Original Message-----
> From: redhat-list-bounces at redhat.com
> [mailto:redhat-list-bounces at redhat.com] On Behalf Of Tolga Evren
> Sent: Wednesday, February 01, 2006 10:53 AM
> To: General Red Hat Linux discussion list
> Subject: RE: linux vs SAN
> 
> We use redhat linux ia64 , with emc . Since powerpath has no version on
> our platform ( redhat 2.1) , we use 2 hba without any multipathing
> software.
> 
> 
> Tolga Evren
> 
> -----Original Message-----
> From: redhat-list-bounces at redhat.com
> [mailto:redhat-list-bounces at redhat.com] On Behalf Of Ciril Ignatious T
> Sent: Wednesday, February 01, 2006 10:34 AM
> To: General Red Hat Linux discussion list
> Subject: Re: linux vs SAN
> 
> You have to install any multipathing software in your system.If u r 
> using Qlogic HBA they will be providing the driver with multipathing 
> support.Other wise you have to use any commercial multipathing s/w s 
> like Veritas Volume manager.
> 
> 
> Regards
> 
> Ciril
> 
> baran.yurdagul at turkcell.com.tr wrote:
> >
> > I have connected my linux box to Hitachi SAN with 2 HBA. I have two
> > nodes and I want to use Veritas as cluster sw. When I wanted to make
> > partitioning and create filesystem on the disks I get a bit confused.
> > Because of 2 HBA, I have seen 4 disks (Infact I have two). I have
> > created a partition and make mkfs.ext3 on to it. But after mkfs.ext3
> It
> > is strange that partitionin info has been flushed. Did you experience
> > such problem before or  is there any documentation or howto etc ??

-- 
Ed Wilts, RHCE
Mounds View, MN, USA
mailto:ewilts at ewilts.org
Member #1, Red Hat Community Ambassador Program