On Fri, Jan 13, 2006 at 04:52:33PM +0000, Howard Winter wrote:
> Alan,
> 
> On Fri, 13 Jan 2006 16:35:10 -0000, Alan B. Pearce wrote:
> 
> > I have been involved in attempting to recover a system that was backed up on
> > floppies, and we had a disk failure just as we were installing a brand new
> > system with a tape drive and attempting to copy the data over ...
> 
> Q.E.D. !  :-)
> 
> Howard's Law of Backups is "Never have just one copy of anything you want to keep", and in cases like this 
> where you are overwriting the original (I think that's what you mean?) the one backup isn't enough!  I've seen 
> this sort of thing happen too often...  the classic was a supposedly experienced IT person who reformatted the 
> hard drive on a live Novell server (a number of years ago) without either taking a backup of his own, or 
> checking that the regular overnight backups were working and complete.  It turned out that they weren't, and 
> his department tried to blame the people who set up the backup scheme...  would you jump out of an aircraft 
> without checking that you were wearing a parachute, and that you were securely harnessed to it???

Definetely... I like my backup system quite a bit... I use Linux so
these commands may sound a bit foreign, but here it goes...

First of all, I have three seperate "groups" of computers, work, my
server, and my laptop. My files are seperated into two groups, d and m.
d is for data that I created myself, and *really* don't want to loose. m
is for data that other people created, like data sheets, music, videos
etc. The latter I can lose and it's just a financial hit. (I buy mp3s
from bleem.com, and I rip every cd I buy and only keep the mp3s!) d is
1gb in size, m is 8gb.

Those two directories get automatically synchronized between those three
groups of computers, work, server, laptop. So I've automatically got
three backups there, in a minimum of two places. (my apartment and work)
Often this is three, as I usually have my laptop with me.

The work computer is automatically backed up every few hours to a backup
server at work. So my data is backed up again. This is done
automatically by a program called rdiff-backup This gives me incremental
backups, so if I delete something, and find out in three months, I can
restore it. I keep the increments for 6 months. The drive holding the
data is a raid1 mirror, so there's another backup right there.

I also manually backup the work computers to an external harddrive,
which I store at my apartment. So I've got a full, manually checked,
backup every month or so. (I tend to forget!) This backup is a mirror of
the above server's backup drive, so it's also got 6 month increments,
often as much as 9 months old. (assuming I forget for 3 months)

Finally I also rent out a virtual server somewhere in the us from
www.unixshell.com These guys are great, they use virtualization software
to make virtual servers out of extremely fast and large Linux boxes. So
they take one big server, say a quad processor Athlon monster with gobs
of ram and hd space, and rent you a virtual server with 96mb of ram, and
3gigs of hd space for $15 a month. So I've got one of those and share it
with my boss. Both are personal directories are automatically backed up
to that server every night, again with rdiff-backup. I set this up
recently, so I've got 4 months of increments there. unixshell also allow
you to make a backup of your server, which I do whenever I make any
configuration changes, in case I fuck up and need to quickly restore my
setup. So that's another backup.

I fairly regularly test all of this, usually after deleting a file...

All in all, 8 backups of my data in three physical places, often four.
With increments going back at least 6 months. Overkill? Yeah, probably.
But it takes so little work once it's setup that I don't care. Doesn't
even cost anything, as my boss pays for that $15 account, and I had more
than enough spare harddrive space everywhere.

I anyone wants any further technical details, like scripts, just ask.

-- 
pete@petertodd.ca http://www.petertodd.ca
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