[H-GEN] DVD+RW media for backups

[Greg Black]

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On 2003-11-17, Robert Brockway wrote:

> The drives are robust (one of them used to go between work & home in a
> backpack while I rode my bicycle).

Can you define "robust" for me?  I know from experience that I
can drop my DDS tapes and that they will work afterwards.  Will
a disk do that?

On a different tack, I can fit several DDS tapes comfortably in
my pocket or in a corner of my briefcase or my laptop's carry
case.  How do the disks fare there?

> The MTBF (mean time between failures) of an IDE drive averages about 5
> years.  The MTBF of DDS tapes is much shorter than this.  A talk by Jason
> Andrade at Sage-Au suggested the MTBF of a DDS tape itself is about 12
> months.

I don't know where Jason gets his data from, but my experience
with DDS tapes at several sites over the past 8 years is that
I've seen two tapes fail (both after more than 100 use cycles
over 5 years and both the less reliable DDS-1 types).  And I've
seen a 75% failure rate in the first 15 months with all the IDE
disks I've bought in the last 3 years.  Obviously, other people
will see different figures, but my experience is not that rare.

> I've had drives in service for >3 years using this regime and are yet to
> see the slightest problem.

Good to hear.

> Every few weeks I see people posting on lists (even Sage-Au) asking for
> info on how to recover from an accidental rm -rf or mkfs or asking for
> recomendations about professional data recovery companies.  Anyone feeling
> the need to ask for assistance on recovery after a disaster should have
> been doing backups.

Absolutely.

> Learn from other people's mistakes and start backing
> up today if you aren't already.  Do this even if you care only a little
> about your data.  Make it an offsite backup too :)

Definitely good advice.

> I've only spent about $600 on my personal backup solution.  Money well
> spent if you ask me.

For small networks and home systems, which is what we're really
covering at Humbug, there are several reasonably-priced backup
solutions that can be setup.  There are two[1] important steps:

 1. Make sure that you do your backups religiously.

 2. Verify them every time.

 3. Verify that you can restore from them successfully.

 4. Automate as much of the process as you can: scripts and cron
    are your friends.

 5. Verify your automated operations separately from the other
    verifications.

 6. Do anything else that seems essential that I've left out :-)

Cheers, Greg

[1] OK, I can't count.  I was just going to cover the first two
    points, but the others clamoured for attention as I was
    writing, so you get them for free ...

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