Failing DAT drive

HP has a pretty good return policy.  When we bought the drives they came
with a three year warranty.  They have been replacing the failed drives,
usually overnight.  I only have about nine months left on the warranties
though.

I get between  4GB-5GB per hour backup throughput so I think the drive is
being well fed.

Hi,

Just can't tell how pissed of I'm with HP.
I had high regard for the company, but they seem to cover this ...

I Had a batch o 4 Compaq DAT 12/24 - HP Built DDS3 Drives - like the DAT
24.
I used them for less than 8GB a day backup's.
All went dead!
The first some 15 day before the end of the first year (and the
warranty,
which is shorter down here in the tropics - Brazil) and Compaq changed
it
immediately (by a Sony built unit).

The second and third both were gone some 30 day after ... 15 day before
Compaq's said the warranty was over, but as they couldn't explain what
was
happening, somebody there gave order to "extend" the warranty and after
some days I've got them changed for working ones (HP Built again).

In the mean time we bought some 10 new units and - thanks god - they
were
all Sony built and are working all right (@ 8 GB/day ==> < 2.5 hs/day).

The fourth drive os the batch, which was backing up only
4 GB/day ==> 1-2.5 hs/day (backup or backup+verify)
is gone also with an year and a half of use.

Compaq won't say nothing. I wanted to have knowledge to do some
predictive analysis as it is to stressful to have a multiple
failure making wreck of any contingence planing.

HP say absolutely nothing in it's site, or it's support forums.
Now and then people complain about it.
I've hear of thermal damage in the heads caused by high duty cycles ...
May be 4 GB/day for a DAT 24 is just too much!
HP has a spec for 12% duty cycle (12% of 24 Hs is 2.9 Hs !).
They should call it a toy, not a torture tested enterprise solution.

Not all Drives are so unreliable. The ones from Sony are just working
fine.
I have some 2 other HP built drives used in less then 2 GB/day ==>
<30min,
not from the same batch, that are still working.
Can I trust them for heavier loads ?

With an 8 hour duty cycle a day, even changing drives won't help.
You should note that the DDS3 and later DAT drives have the
"read-after-write" feature, and the drive retries up to 255 times
till writing ok or giving an error; and when the backup seems ok it is
ok.
(I've done a lot o testing to check it!)
May be you can verify only from time to time, and the duty cycle is
halved,
giving you better reliability overall.

You should also check if the drive is streaming. I get from 3 to 6 GB/h
with those drives depending on the system load and small file/empty dir
load.
if the  tape isn't streaming the tape will "shoe-shine" the magnetic
heads
shortening even more their life.

In case you use Sbackup in nw 4.x, optimization IS BADLY needed.

Let's open a SIG on HP's bad policy of covering up the faulty history
of it's toy/enterprise-stressfull drives, instead of doing a recall.
They should know if all the drives are bad, or just some of them.
And we should be told the real reliability we are buying.

Well,

Hi!

I've used my HP DDS3 drive 5 days a week, backing up 16 gigabytes whith
verification. It works fine near 2 years and 6 month and then dead. HP
warranty is 2 years and better solution is get new device. In Your case
You may have 3 years of warranty (Your device is newer) and may be You
need to contact HP?

Regards,
Alexey