[linux-lvm] Adding xfs module to the initrd-lvm

[Ken Fuchs]

To: linux-lvm at redhat.com
In-reply-to: <20040302154631.GB12779 at tykepenguin.com> (message from Patrick
	Caulfield on Tue, 2 Mar 2004 15:46:32 +0000)
Subject: Re: [linux-lvm] Adding xfs module to the initrd-lvm
BCC: kfuchs at unicycling.org
References: <20040302152911.GI15556 at tangerine.coulon.evette> <20040302154631.GB12779 at tykepenguin.com>
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>On Tue, Mar 02, 2004 at 04:29:11PM +0100, Jean-Luc Coulon (f5ibh) wrote:

>> I would like to add the xfs module to the lvm created by  
>> lvmcreate_initrd.
>> 
>> Is there a mean to do that easily?
>> So I have to mount and existing one and add the module by hand?

Patrick Caulfield wrote:

>I suspect that's the easiest way if that's what you really need to do.

>> So I have to use the standard initrd tools?

>You could edit the existing lvmcreate_initrd to add the module (look
>for lvm-mod and write some similar code underneath it).
>
>But the easiest way, by far, is to have your kernel with XFS compiled
>into it rather than as a module!

An alternative is to simply modify the initrd manually (Very easy and
rather straightforward):

Make a backup copy of the initrd.

(If the initrd is compressed, uncompress it using gunzip.)

# mount -o loop /boot/initrd-<version> /data1
# cp -p /lib/modules/<version>/kernel/fs/xfs/xfs.o /data1/lib/modules/<version>/kernel/fs/xfs/
  <Destination directory can be anywhere as long as insmod arg in linuxrc
   matches.> 
# <edit> /data1/linuxrc
  <Add insmod command to insert module xfs.o.>
  /bin/insmod /lib/modules/<version>/kernel/fs/xfs/xfs.o
# umount /data1

(If the initrd was compressed, compress it using gzip.)

# shutdown -r now

Rather than replace the original initrd, one could copy and modify it
and make a new lilo or grub entry for the old kernel/modified initrd.
This allows one to boot from the original kernel/initrd in case the
modified initrd contains a mistake that prevents proper booting.

Sincerely,

Ken Fuchs <kfuchs at winternet.com>