On Friday 20 May 2005 03:59 am, Stephan Wehner wrote:
What am I trying to back up?
What happened to me was I was running Mepis, and did an apt-get xfce4 (I
think it was xfcr4). But then startx wouldn't work any longer. I thought
apt-get would be pretty safe...
Then I switched to FreeBSD and after a port-upgrade installed the new
version of firefox. Then firefox wouldn't work any more.
In both cases I had no clue what had changed, or how to undo it.
Hence my original question. I think starting over with OpenBSD will be
worth it. But I'm trying to decide on a good way to set up backups
right from the start.
What have done since OpenBSD 2.8 (and for SunOS for many years before
that) is keep 2 copies of the OS on disk. That is, I use the following
OpenBSD partitions:
wd0a root (fstab mounts root, usr, home)
wd0b swap
wd0c entire disk
wd0d root2 (fstab mounts root2, usr2, home)
wd0e usr
wd0f usr2
wd0g --unused--
wd0h home
By default I use the wd0[ae] partions (boot from wd0a), and [df]
aren't mounted. Being unmounted, they're fairly immune to most
clumsy-fingering-as-root disasters. But if something goes wrong,
I can boot the [df] partitions.
Usually I do system upgrades only on the [ae] partitions, leaving
the [df] ones unchanged as emergency backups.
For example, right now I'm running 3.5-stable, but this weekend I hope
to install 3.7 and move immediately to 3.7-stable.
[Yes, I've bought a CD.]
But I'll do this on wd0[ae] only. That way if something goes horribly
wrong, I can boot from [df] and have a working 3.5-stable system.
If 3.7 goes as smoothly as every past OpenBSD upgrad has, then in a
month or two I'll copy [ae] to [df] (via dump|restore), fixup root2's
/etc/fstab, and run installboot on it.
The main cost of this scheme is the disk space for a 2nd copy of the
root partition, (var if you have a separate partition for it) and the
usr partition. In 1993 when I had only a 670MB disk, duplicating
root+usr was painful. But today, when the smallest laptop disk is
30+ GB, 2 or 3 GB for a duplicate OpenBSD is (IMHO) a trivial price.
Of course, YMMV. Don't try this scheme unless you're reasonably
familiar with the OpenBSD booting system, /etc/fstab, installboot,
mount, and other such commands.
ciao,
--
-- "Jonathan Thornburg (remove -animal to reply)" <[EMAIL PROTECTED]>
Max-Planck-Institut fuer Gravitationsphysik (Albert-Einstein-Institut),
Golm, Germany, "Old Europe" http://www.aei.mpg.de/~jthorn/home.html
"Washing one's hands of the conflict between the powerful and the
powerless means to side with the powerful, not to be neutral."
-- quote by Freire / poster by Oxfam
