backup

[Mike Bartman]

At 04:32 PM 6/16/04 +0500, Vano Beridze wrote:
>Hello
>
>I have a PC at work and I want to backup data on  a regular basis.
>Could you please point to some reading materials on how to do that?
>
>I want a simple backup of some files, to some file I think would be enough.

How many files?  What total size are you talking about?  What hardware do
you have available?  Tape drive?  CD-burner?  USB thumb drives?  Floppy
disks?  Network file server?  What??

My preferred backup method involves removable hard drive trays installed in
the PC, with a spare disk for the system, and a scratch data disk for
normal use.  When I want to backup, I shutdown, remove the scratch disk
(which normally holds the swap partition and a scratch (i.e. never backed
up) data partition, and plug in the spare system disk.  I then use System
Commander's partition copy capability to copy the live system disk's
partitions to the spare disk (Drive Copy or a number of other standalone
disk/partition copy utilities would work too...I already had SC).  Then I
remove the spare, put the scratch back in and reboot.

This gives me a "hot spare" with everything on my live system on it.  It's
cheaper than tapes (a 20 gig HD is cheaper than the number of tapes it
would take to back up a drive of that size).  It backs up *everything*
since the OS isn't running (no open files, no file conflicts, no files
half-modified on the backup copy).  I can selectively restore whatever I
might need to by swapping disks again and mounting the partitions from the
backup drive and then just copying files.  It's faster than almost any
other backup method (20 gigs in a couple of hours, with no media swapping
required).  

The easier and faster a backup is, the more likely you are to have current
ones when you need them...

If I was a bit more paranoid, I'd modify the procedure in a couple of ways:

1) Have two backup disks...an "A" and a "B" and alternate using them at
each backup.  That way if the system gets fried *during* a backup, I've
still got another...though one generation older.  The non-use one would be
stored off-site somewhere.

2) I'd swap the "live" disk and the backup at each backup.  I.e. after
doing the backup, I'd use the *copy* as my live disk, and the previously
live disk would become by backup.  That way I test by backup as soon as
it's made...and don't find out at the worst possible time that the backup
isn't usable.  I also equalize the wear and tear on all the drives.


It works for me anyway.  The removable drives also makes it easy to test
out new OSs.  You just pull the system drive and plug in a spare, install
whatever, test as much as you like with the riskiest software you care to
experiment with, then just pull that drive, plug in your live disk, and you
are back in business with your usual setup.  The test disk is there for the
next play session with nothing but a reboot and 10 seconds of drive swap to
get going again.

-- Mike B.
"In the representative system, the reason for everything must publicly
appear. Every man is a proprietor in government, and considers it a
necessary part of his business to understand.  It concerns his interest
because it affects his property.  He examines the cost, and compares it
with the advantages; and above all, he does not adopt the slavish custom of
following what in other governments are called 'leaders'."

				-- Tom Paine, _Rights of Man_ (1791-92)