Tape vs disk cost

[Jerry Feldman]

On 03/29/2010 01:50 PM, Mark J Dulcey wrote:
> So... tape remains attractive for big data centers, especially ones tha=
t=20
> have to keep multiple generations of backups for legal reasons. But at =

> least on the numbers, external hard disks look like the winner for=20
> individuals and small businesses, perhaps combined with online backup a=
s=20
> a second line of defense.
>  =20
One issue I have with disk backup is not the media per se, it is
procedure or simply human error. I've seen cases where a computer
operator mounted an empty drive for backup, and then restored the empty
drive to the production drive.  A few weeks ago when I decided to
rebuild my system after I was not able to create a RAID1 LVM volume
(bugzilla has been filed, and reportedly fixed) I was extra careful not
to mess up my backup drive. At work we do rsnapshots to a NAS device,
and New York does an rsync on it nightly so if our data center gets
zapped we should be able to rebuild. I personally prefer backing up to a
physically attached drive whether another drive in the cabinet or a NAS,
but a major electrical issue, such as lightning can zap your entire
system. removing the backup device while not in use reduces your
exposure, but you run the risk of forgetting to insert the backup media
just before you will end up needing it. At HP we backed up to tape which
we left in until if filled up, but if someone forgot to rotate it, we'd
go without a backup. In any case, there is all sorts of issues and
strategies. During Katrina, I believe it was Chevron that not only lost
their data center but also their offsite storage center.

--=20
Jerry Feldman <gaf-mNDKBlG2WHs at public.gmane.org>
Boston Linux and Unix
PGP key id: 537C5846
PGP Key fingerprint: 3D1B 8377 A3C0 A5F2 ECBB  CA3B 4607 4319 537C 5846