Re: tlug: disk image distribution

["Frank Bennett (=?iso-2022-jp?B?GyRCJVUlaSVzJS8kWSVNJUMlSBsoQg==?= )" <bennett@example.com>]

On Tue, Nov 02, 1999 at 10:25:22AM +0100, Marcus Metzler wrote:

> I am looking for a solution that allows me to install a disk image on
> several computers over the net.

In the computer lab here, we do rotating reinstalls of this kind on our
Win95 workstations, which otherwise seem to grow progressively more
unfriendly over time.  Our command for the restore is (quoting from
memory): 

  rsh 133.6.33.XXX cat /backup/RESTORE.IMAGE.gz | gzip -dc | \
    dd of=/dev/hda

The backup line looks (something) like this:

  dd if=/dev/hda bs=<blocksize> count=<size> | gzip -c | \
    rsh 133.6.33.XXX cat - ">" /backup/RESTORE.IMAGE.gz

The idea is that the backup exactly lifts the in-use territory
of the physical disk, compresses the resulting data stream and
saves it in a (really very big) file on the server.  Restoring
is simply a matter of streaming the file across to a workstation,
uncompressing it, and laying it back down on the physical disk.

A few caveats.  The command is executed after booting the machine to Linux
from a floppy disk, with the entire disk to be saved or restored left
unmounted.

You get an EXACT replica of the original by this method.  If you don't use
bootp or dhcp to acquire IP addresses on your workstations, you'll need to
fix the IP settings by hand.  If you use Windows of some description, the
NET-BEUI name for the workstation will have to be fixed by point and click
and point and click and point and. 

For the same reason, you end up with exactly the same partition sizes on
the restored machines, no matter what the real disk area is.  We have made
the older machines the common denominator, so we have gigabytes of disk
lying around in the lab.  That's okay, though; it still serves to make the
place more high-tech.

If your lab has a mixture of machines with SCSI and IDE primary drives,
you can lay the disk image from one type onto a disk of the other type,
but you will need to do some jiggery-pokery (reinstall MBR?  Reset active
partitions?  Change root disk flag in Linux kernel?  I forget which of
these) to get the restored machine to reboot.  But you can use the same
base image for both, which saves time.

I should also say that you've got the right idea; using this method has
saved us a HUGE amount of clicking and fiddling time on the Windows
machines.  I have even begun opening please-help-me sessions with a gentle
suggestion to whoever it is that they should pay close attention, because
their troubles are probably down to something that they are getting wrong. 
Previously, I had too often found myself giving a abject closing apology
on behalf of Uncle Bill's Bug Farm.

Cheers,
-- 
-x80
Frank G Bennett, Jr         @@
Faculty of Law, Nagoya Univ () email: bennett@example.com
Tel: +81[(0)52]789-2239     () WWW:   http://rumple.soas.ac.uk/~bennett/

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