lenny hosting wheezy chroot
I am looking for advice on how to run a wheezy chroot from a lenny host,
in particular how to handle dev, udev, and X.
BACKGROUND
My system is running lenny and I wanted to use python 2.7. I upgraded
debootstrap from backports and then created a wheezy (actually,
"testing") chroot with --variant=minbase. After some rough spots (I
needed to bind mount sys and proc, and eventually /dev/pts, and install
a package so debconf could ask questions during the install) thing seem
to be running.
Now I want to try mythtv in the chroot, which requires X, which I
believe requires /dev to be hooked up properly. The Debian Reference
for lenny provides some instructions about setting up using a different
virtual terminal (the current version does not:
http://www.debian.org/doc/manuals/debian-reference/ch09.en.html#_chroot_system. The lenny reference suggests running MAKEDEV. Most other sources suggest mount -bind is the way to go, but some people caution this can lead to trouble (and there were some Debian bugs (http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=623060_ in this scenario).
SPECIFICS
Some advice is to install udev in the chroot, and I believe installing
myth would force in udev. Some specific concerns:
1. udev does a lot at system startup. Since the chroot never boots,
that code, which may even include scripts that launch daemons, will
never execute.
2. I'm concerned that sharing /dev's will cause the chroot to affect the
host OS. Apart from bug 623060 (which I hope applies to a version I'll
never see), I'm concerned about 2 X servers competing (even if assigned
different VT's), and concerned that logs from the chroot will end up
going to the host, probably via /dev/pts (since there were messages in
the chroot that it couldn't log because there was no /dev/pts). To
repeat: currently I share /dev/pts, but not /dev.
3. The testing udev may require kernel features not available in the
kernel the host is running, 2.6.26-2-686 #1 SMP.
4. Would it be possible for the chroot to use the host as the X server?
The net also shows suggestions to use schroot, which I may explore.
However, I would like to understand what is going on under the hood.
Further, the easiest thing is to use the lenny schroot (or a backport if
available), and that might not handle wheezy well.
It's possible that a wheezy chroot inside a lenny host is just not
advisable. Please say so (and why) if you think so.
FYI I have a single core P4 without hardware virtualization. This is
one reason I'm trying a chroot and not a VM. I also thought a chroot
would be simpler :) I am not especially concerned about chroot
security, except in the sense that I don't want to inadvertently mess up
the host from inside the chroot.
Thanks for any advice.
Happy Holidays to all--or least all for whom these are holidays!
Ross Boylan
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