[linux-lvm] Installing Linux on LVM

[Wade Curry]

Glenn Shannon(warl0k at lvcm.com)@Tue, Aug 07, 2001 at 10:09:26AM -0700:
> Hi all!
> 
> I was wanting to install Debian onto an LVM partition. Does anyone here know
> if this can be done or am I going to have to try and figure it out all by my
> lonesome? :)
> 
> I have a bunch of experience in installing/patching LVM beta 7 and am
> planning on using beta 8.
> 
> Also, does anyone know of a bootloader that will recognize an LVM partition?
> It would be kind of wasteful if I installed linux only to have to boot from
> a floppy :)
> 
> Thanks in advance for any replies!
> 
> Glenn
> 

The docs are out there, but the information on this topic isn't
explicit or abundant.  What you're asking about is installing root
on LVM, if I understood your request correctly.

In general terms, these are the steps:

1. Create a boot partition and swap not on the LVM.  This will be 
   permanent.
2. Create a minimal installation on a small partition (regular
   ext2).  This will not be permanent, so no need to be elaborate.
3. Compile a kernel that has support for LVM and your choice of fs
   and ext2 statically linked.
4. Create your logical volumes, etc. on the rest of the disk space.
5. Use lvmcreate_initrd to create an initrd so the kernel will be
   able to find everything in the new root lv.
6. Use debootstrap to create an installation on the new root.
   This is not smooth, and does not run through normal style
   installation scripts.  You will most likely have to use
   chroot and dpkg to get the locales package installed for
   debootstrap to even complete successfully. You'll want to copy
   some of the things from /etc/ and check them out. fstab and
   lilo.conf will need to be modified.  A lot of little steps here
   just making sure that you can boot, and can get to your source
   of debian packages.
(at this point you can run dpkg/apt and install a _lot_ of stuff
before you reboot.  But be careful, symlinks won't necessarily
point where you think they do.)
7. Run lilo with your new config and reboot.
8. Fix the details you overlooked in step 6 :)
9. Finish selecting packages and installing.
10.Thank the debian maintainer for making normal installations so
easy (Something I thought I'd never say! :).
11. If desired, incorporate the disk space for the original install
    into your lv.

I regret not writing down details of the process while doing it.  I
was playing it by ear, and my original install was complete and had
important data that I wanted to be extremely careful with. The pace
was slow and easy.

I was using 2.4.7-pre3 with the latest patches at that time, devfs
(with no devfsd), and have had to work through a lot, but learned
quite a bit (my main reason for doing this).  Manual installation
and going without devfsd were more difficult than any of the issues 
with LVM. Most of the difficulties are overcome by reading docs,
and being alert to the error messages and other "progress
indicators".

Have fun!

Wade Curry                            wcurry(AT)cts.com

Do I have to compile it?            Looking for a position
No, I *get* to compile it.          working with *nix as a
It's about freedom.                 Sys. Admin. or other.