distro OS-tan (includes Ubuntu), system rollback

[John]

Paul Sladen wrote:

> 
> Interestingly, full-system rollback was something that was investigated in
> Sydney and given how much free space people's hard-drives come with, it
> would be an interesting idea to look at long-term how to make use of all
> that unused space to keep backups.
> 
> A full/partial revision-control system would probably be an good research
> project for somebody to do.  You'd want a way of prioritising data so that
> you didn't waste space keeping backups of people's DivXs when it would be
> better to keep lots of revisions of the 20kB document they are (were)
> working on (and just deleted).

Umm.

I had a Nasty Accident a couple of weeks ago. I had a box with two SCSI 
and one ATA drive.

I spotted /dev/sda was getting tired and took a backup to /dev/hda. 
Sadly, of my 2.4 Gb backup I could read about 300 Mb. As far as I could 
tell it was just the root filesystem. /var and /boot were (following the 
usual advice) other partitions.

This was my server from which I do network installs, and was running Sarge.

About the only choices of software that came to hand for a new server (I 
was not buying a new SCSI drive for that old box) was nahant *RHEL 4) 
beta and WBEl 4.

So, I had much fun creating a replacement server _and_ converting from 
Debian to (basically) RH in no time flat.

It took some time (and not just from my fumbling unless choosing an 
incopentent dealer counts as my fumbling).

What I don't have is
a) All the mail. I run an imap server, and the mail was in /var.
b) A catalog of what software Ihad installed.
c) All my network boot tricks.

I do have most of the configuration info as /etc seems fin, but of 
course it takes some translation.

The moral of the tale: I don't think a lot of the idea of backing up to 
the same hard drive. When sda died, I couldn't find a sector that I 
could read and I tried a few different regions with dd.

For serious backup, another drive is required. For serious serious 
backup, a backup server (at least) us needed.