At  12:05 PM 5/2/2002, Chuck Ryan wrote:
>I have a 939ks-020 running 6.0pp2 with a DDS3 DAT drive. Currently backups
>are taking a little over 3 hours to run which is killing me when I try and
>squeeze my nightly production run around it.
>
>What would be a good upgrade to the DAT that my system can keep a steady
>stream of data into? I don't want to spend a ton of cash on a drive my
>3000 cannot keep busy.

DDS was a great technology 10 or 12 years ago.  Today, it's barely "good
enough".  DLT is the current sweet-spot in storage for most HP3000
systems.  And DLT4000 drives can be quite
affordable.  http://www.pricewatch.com shows me multiple vendors selling
DLT4000 drives from US$295.00 (a refurbished internal SE-SCSI, but with
free shipping) or US$300.00 (new, internal, SE-SCSI, plus $20.00 shipping)
and up.

BTW, the DLT4000 stores 20GB native (plus whatever compression it achieves,
depending on your data) at 1.5MB/s on a DLT-IV tape (presently about
US$51.00 *each* and up), but it stores 15GB native (plus compression) at
1.25MB/s on a DLT-IIIxt tape (presently about US$25.00 each).

[Warning:  Generalizations and simplifications abound in the following.]

DDS drives all seem to have a duty-cycle rating of "one tape per day".  DLT
drives have a duty cycle rating that basically says "use them all day long
if you want".  And it's been a few years but the last time I looked at the
specs DLT drives were literally 1000 times (3 orders of magnitude) less
likely to have unrecoverable data errors than DDS drives.

For folks looking for high-capacity drives, LTO/Ultrium drives look like
they might steal the limelight over DLT's successor, SDLT, but it's too
early to see which format will become dominant in that performance range.

--
Jeff Woods
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Quintessential School Systems

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