[plug] shared /home for dual-booting two distros

[meyerri]

---- Original Message ----
From: sales at ecosolutions.com.au
To: plug at plug.org.au
Subject: RE: [plug] shared /home for dual-booting two distros
Date: Tue, 30 May 2006 17:03:28 +0800

>This a newbie-ish question ;-)  Is it feasible to share one /home
>with
>two distros?

Yes!!
>
>Scenario: 
>I have two newly-installed distros.  One is an upgrade of a distro
>I'm
>well familiar with, and the other is a distro I trying out as an
>alternative (no names, no pack drill ;-) ).  The 'primary' distro was
>installed first and I created /home on a separate partition, 'sdc'.
>Swap is 'sdb' and I just lumped everything else on 'sda' as a '/'
>partition.  I installed the 2nd distro on it's own partition, 'sdd',
>leaving the old '/home' as it was.  I dual-boot with grub to decide
>which distro to play with.  During the install, I pointed the second
>distro to the original (and only) swap partition, 'sdb', and this
>seems
>to be okay for both distros to use in turn.

Yup, swap areas are usable across different distros (not as separate
VMs under VMware for instance)
>
>Straight off, I have some minor glitches because of my inexperience
>in
>doing this.  First, the 2nd distro created its own '/home' in its
>'sdd'
>partition.  Is there any way I can tell it to use the original
>'/home'
>on 'sdc' _during_ the install? 

Yes, but seeing you're keeping the distro secret we can't tell you
exactly how. ;-)

 I thought I had, but not so.  Second,
>the original '/home' is not mounting at boot, so I guess I'll have to
>manually put it in my fstab.  Other than that I guess I could use
>hard
>links (or symbolic links?) to point the 2nd '/home' to 'sdc.  Is that
>right?

You can mount the original "/home" (hdc) at another point like
/mnt/tmp and refer to your original ~ as /mnt/tmp/gavin (if ~ was
/home/gavin). Copy what you want out of your /home/gavin to
/mnt/tmp/gavin and then delete the whole /home/gavin directory, and
change the mount point for /hdc from /mnt/tmp to /home. But, there
are things which will bite you in the butt. See below.
>
>However, even once overcoming that minor glitch could I get myself in
>knots, with conf files and the like, by trying to run separate
>versions
>of firefox, for example, when I boot each distro in turn and its apps
>try to write to the shared '/home'?  I could see that different
>distros
>modify files in different ways, so should I avoid what I'm trying to
>do?

Yes you could get yourself horribly tangled up between releases of
KDE, Evolution, Firefox, maybe even OOo, and I was going to mention
it. If you DO want to mount your /home to another distro, it might be
a good idea to create your username on distro2 to be something
different to the username on distro1. Also you have to beware of
numerical userids. Some distro start creating userids from 1000,
while others start at 500 for instance. So you can end up with a ~
directory that you can't do anything with because, although you have
the same username, it's a different numeric ID.
>
>Thanks, Gavin
>
Cheers
RM