[linux-lvm] How to boot with LVM?

Neil Macvicar neilm at foobarhouse.com
Thu Sep 13 12:15:43 UTC 2001


If it's any help, I have put my initrd on public ftp at
fruits.foobarhouse.com in the LVM directory. It's served me well for as long
as I've been using LVM'ed root.

I'm currently using LVM 0.9.1beta8.

Regards,
--Neil.

----- Original Message -----
From: "A.R. (Tom) Peters" <tpeters at xs4all.nl>
To: <linux-lvm at sistina.com>
Sent: Thursday, September 13, 2001 8:18 AM
Subject: [linux-lvm] How to boot with LVM?


> I bought a 30 GB HD, and decided to put it under the LVM and put
> ReiserFS on it.  I managed to initialize it fine, and it now has a base
> Debian install on it, but I cannot manage to boot from it.
>
> You cannot boot from a LV; therefore I made a small (16 MB) ext2
> partition with a kernel and an initrd.  My intended root FS is on a LV,
> and you need to jump through some hoops to get the kernel mount it on /
> : that is documented in the LVM-HOWTO and FAQ that comes with the LVM
> tools.  Use of initrd is documented in
> /usr/src/linux/Documents/initrd.txt .  Finally, the Bootdisk-HOWTO
> helps.
>
> I use LVM tools 1.0.1-rc2, and a 2.4.10-pre7 kernel, patched with the
> patches of the LVM tools; no .rej there.  I compiled the LVM binaries
> with liblvm-10 statically linked, because otherwise the executables in
> the initrd had problems with finding the .so (I think I know what was
> going on, but won't go into that now).  Therefore I have to make a
> Ramdisk of 5MB instead of the default 4 MB.
>
> My new HD is /dev/hdd, and is the 3rd HD in the system: this allows me
> to still use my computer to read docs and send you this message.  So for
> now I do not want to put a bootloader on the disk because the hardware
> config is going to change: instead I use a boot floppy with GRUB.
>
> LVM has a utility script lvmcreate_initrd to make an initrd suitable to
> prepare for mounting a LV on / .
>
> The system boots with the floppy; the correct kernel is loaded from the
> ext2 partition, as well as the initrd; the LVM tools on the initrd are
> executed and seem to work properly.
>
> PROBLEM: subsequently the kernel panics because it still cannot mount a
> root.
>
> I got a GRUB bootdisk that works.  /grub/menu.lst :
> title  Linux24
> root (hd2,4)
> kernel /vmlinuz-2.4.10-pre7 root=/dev/SYSDISK/Root ramdisk_size=5120
> # If I specify root=/dev/ram0 then I get a shell on the rudimentary
> initrd system.
> initrd /initrd-lvm-2.4.10-pre7.gz
>
> On initrd:
>
> etc/fstab:
> /dev/ram        /               ext2    defaults        0   0
> proc            /proc           proc    defaults        0   0
>
> linuxrc:
> #!/bin/sh
> /bin/mount /proc
> /sbin/vgscan
> /sbin/vgchange -a y
> /bin/umount /proc
>
> devices:
> # ls -l dev/SYSDISK/
> total 0
> brw-rw----    1 root     disk      58,   2 Sep 11 19:23 Opt
> brw-rw----    1 root     disk      58,   0 Sep 11 19:23 Root
> brw-rw----    1 root     disk      58,   4 Sep 11 19:23 Scratch
> brw-rw----    1 root     disk      58,   1 Sep 11 19:23 Usr
> brw-rw----    1 root     disk      58,   3 Sep 11 19:23 Var
> crw-r-----    1 root     disk     109,   0 Sep 11 19:23 group
>
> Kernel:
> # rdev vmlinuz-2.4.10-pre7
> Root device /dev/ram0   # Root device /dev/SYSDISK/Root
>   (-> 0x3a00) does not make a difference
> # rdev -R vmlinuz-2.4.10-pre7
> Root flags 0    # i.e. mount ro
> # rdev -r vmlinuz-2.4.10-pre7
> Ramsize 49152   # i.e. offset=0; bit14=1: load ramdisk; bit15=1:
>                 #   prompt before loading rootfs - this never happens!
>
> What am I supposed to change?  The kernel initrd.txt has a long and
> complicated story on using pivot_root to switch rootfs, but apparently
> the LVM linuxrc relies on the deprecated method that does this
> automatically.
>
> Any advice welcome.
>
> --
>
#>!$!%(@^%#%*(&(#@#*$^@^$##*#@&(%)@**$!(&!^(#((#&%!)%*@)(&$($$%(@#)&*!^$)^@*
^@)
>
> Tom "thriving on chaos" Peters
> NL-1062 KD nr 149 tel.    +31-204080204
>   Amsterdam e-mail  tpeters at xs4all.nl
>
>
> _______________________________________________
> linux-lvm mailing list
> linux-lvm at sistina.com
> http://lists.sistina.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://www.sistina.com/lvm/Pages/howto.html





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