Re: Installing RHEL with single controller

From: Chandra Seetharaman <sekharan@us.ibm.com>
To: Pradipmaya Maharana <pradipmaya@gmail.com>
Cc: device-mapper development <dm-devel@redhat.com>
Subject: Re: Installing RHEL with single controller
Date: Thu, 28 Feb 2008 16:15:55 -0800	[thread overview]
Message-ID: <1204244155.4963.95.camel@linuxchandra> (raw)
In-Reply-To: <110b17190802281507l755d7bd0hb8fd9e83e5dc1374@mail.gmail.com>

On Thu, 2008-02-28 at 15:07 -0800, Pradipmaya Maharana wrote:
> Ok; this is what I did:
> 
> mkinitrd   /boot/initrd.final.img   2.6.18-53.el5xen   --with=dm-multipath
> 
> Changed the /boot/grub/menu.lst file to point to new initrd image file.
> Reboot is fine but multipath -ll is still null. :(
> 
> What am I missing here.

That is odd!!

What version of RHEL do you have ?

Do you see 2 scsi devices (sda and sdb) for the same lun when your
system is up ?

Can you send the o/p of mkinitrd.

Can you extract the file "init" from your initrd image and send it.

Can you check if the device is blacklisted in your multipath.conf file ?

> 
> Regards,
> Pradipmaya.
> 
> 
> On Thu, Feb 28, 2008 at 1:36 PM, Chandra Seetharaman
> <sekharan@us.ibm.com> wrote:
> > On Thu, 2008-02-28 at 12:11 -0800, malahal@us.ibm.com wrote:
> > > Pradipmaya Maharana [pradipmaya@gmail.com] wrote:
> > > > Multipath is getting loaded, if that is what you are wondering about.
> > > > After reboot I check for multipathd status, and smod for the modules
> > > > loaded, everything looks fine.
> > >
> > > No, I am asking if initrd image contains multipath commands. You need to
> > > use cpio to extract the initrd image and see the source code to check
> > > it!
> > >
> > > multipath has to be loaded and *run* before mounting your real root. If
> > > it gets loaded after  mounting your real root, it is too late to have
> > > multipath on root disk! Looks like you need to regenerate initrd with
> > > multpath support.
> >
> > Yes, Malahal is right. You need to create initrd with multipath tools.
> > You can do this by running mkinitrd with "--with=dm-multipath"
> > (Follow the SLES10 installation instructions in my documentation
> > http://sources.redhat.com/lvm2/wiki/MultipathUsageGuide )
> >
> >
> > > --Malahal.
> > >
> > > --
> > > dm-devel mailing list
> > > dm-devel@redhat.com
> > > https://www.redhat.com/mailman/listinfo/dm-devel
> > --
> >
> > ----------------------------------------------------------------------
> >    Chandra Seetharaman               | Be careful what you choose....
> >              - sekharan@us.ibm.com   |      .......you may get it.
> > ----------------------------------------------------------------------
> >
> >
> >
> > --
> > dm-devel mailing list
> > dm-devel@redhat.com
> > https://www.redhat.com/mailman/listinfo/dm-devel
> >
-- 

----------------------------------------------------------------------
    Chandra Seetharaman               | Be careful what you choose....
              - sekharan@us.ibm.com   |      .......you may get it.
----------------------------------------------------------------------