15 Aug
2008
15 Aug
'08
12:13 p.m.
On Friday 15 August 2008, Eric J Korpela wrote:
On Thu, Aug 14, 2008 at 12:12 PM, Jules Richardson
If you think that DLT was unreliable, you must have had bad (Imation)
tapes, tried to use DLT8000 or cheap-o DLT-1 drives. We had very few
problems with Fujifilm tapes, and DLT7000 drives... not that we didn't
have any problems, but it was in a high-usage environment (HSM) that I
wouldn't have wanted to think about trying to power enough disks to
store that much data.
Our compression rate is at least 1.5:1 on average, we've found too.
FWIW, you can get LTO-2 drives for under $500 (I paid $500 for a
top-o-the-line used IBM LTO-2 drive about a year and a half ago), and
tapes for quite cheap these days, around $20-$25 for good quality
Fujifilm LTO-2 tapes.
I also think that comparing the cheapest possible SATA drives to
high-end LTO tapes is a bit like apples to oranges; you might as well
compare LTO drives to $1/GB FC/SAS disks, which have a similar market,
reliability, and speed.
Also, if you want to complain about speed, it's hard to find a single
disk that can keep up with the streaming speed of a new LTO-4 tape
drive.. Tape is keeping up with disk technology just fine. LTO-3 is
over 100MB/sec itself, and I've seen at least 50MB/sec off of my U160
SCSI LTO-2 drive.
Pat
--
Purdue University Research Computing --- http://www.rcac.purdue.edu/
The Computer Refuge --- http://computer-refuge.org
Yep - there was an awful lot of proprietary stuff
out there.
Personally I'm a DLT fan - like you say, it's expensive, but it's
worth it for the reliability.
I'm totally off tape. Our experience with DLT is that the drives
don't last, transfer rates are too slow, and the media are too
unreliable and too expensive. Haven't tried LTO Ultrium, but for
$1700 for a drive and $40 for a 400GB (uncompressed) tape it's too
expensive when you can get 750GB SATA drives for $150. (The
crossover point is 17TB).