[rescue] Tape drive woes

[Sheldon T. Hall]

 Phil Stracchino said ...
> On Tue, Sep 14, 2004 at 11:14:47AM -0700, Sheldon T. Hall wrote:
> > Phil Stracchino writes ...
> >
> > > Does anyone have any suggestions on where I might possibly
> > > lay my hands on a retired-but-working
> > > AIT/VXA/Mammoth/LTO/Ultrium/whatever
> > > class tape drive, in the event that my VXA-1 has indeed
> > > rung down the heavenly curtain and joined the choir
> > > invisible?
> >
> > I have an Exabyte 8mm 5GB drive that's surplus to my needs.
> > Ditto an IBM
> > DDS-2 (2/4 GB).  Would either of them help?  Either could be yours.
>
> They'd probably work at a pinch, though I'd need to buy an
> unholy number
> of tapes or drastically cut down on my backup sets.  (There's
> currently
> around 120GB of data in my full-backup set, while weekly differentials
> incrementals run 2-3GB or so and incrementals run on the order of
> 1-1.5GB a night.

You don't want to do 120 GB to either of those, it would drive you mad.
IMHO, neither format is reliable enough to depend on differentials unless
you do frequent level 0 backups.

> DLT, right, that's the other format I was trying to think of
> and totally
> blanking on.  About how much did you pay for them, and what's the
> capacity of a DLT3?

DLT-IIIxt hold 15 GB straight, nominally 30 GB compressed.

That's _not_ the latest format, though.  More recent stuff holds much more,
and the newer-format tapes seem to be cheaper, too.

Both the drives I got off eBay are Compaq-labelled drives; I think they are
built by Quantum.  They seem very stoutly built.  I paid $75 for one in a
Compaq external Centronics-SCSI case, and $30 for a bare one.  Both work
great and are in use here.

Later, I bought a third one in a smaller Compaq case with 68-pin connectors;
I got it at a local PC junk place for $5.  It doesn't seem to work, though.
If I can't fix the drive, I'll just use the case for something.

A quick look at eBay shows several "Compaq DLT" drives in the same price
range I paid.

DLT tapes are not cheap, but they seem to last a long time.  With the amount
of data you're talking about, though, you probably need one of the later DLT
formats; at $30 each, the 4 DLT-IIxt tapes to store a 120 GB level 0 dump
are going to cost you more than the drive.  Later DLT formats hold up to 80
GB (compressed) per tape, and the tapes cost the same....

-Shel