manager@a.coe.wvu.wvnet.edu (Cris Fuhrman, Systems Manager) (04/04/89)
Salut,
(I posted this a couple of weeks ago, but never saw it appear on INFO-VAX
or comp.periphs, so I'm guessing that there was a problem)
Here at COE, we're looking into obtaining a high-capacity tape drive to
ease some of the data backup pains we've been experiencing for some time.
We have the following computers:
o VAX 11/785 running VMS (1600 bpi 9-track tape drive)
o 10 Sun 3/50/60's running Sun OS 3.5 (1/4" SCSI drive on servers)
o Harris HCX/9 running HCX/UX 3.0 (1600 bpi 9-track tape drive)
For the most part, the rattle and hum on the net mainly deals with ExaByte
8mm drive systems. As many of you in education well know, the bidding
process that exists to obtain equipment may not always yield the most
popular choice in a product (especially since the most popular is usually
the most expensive). So I'm asking where I can get some information about
high-capacity tape drives OTHER than ExaByte. I have brochures from the
following companies:
Company Product Name
------------------------------------ -----------------
Eakins Associates, Inc. miniMAX (8-mm)
Transitional Technology, Inc. CTS-8 (8-mm)
Summus Computer Systems GIGA Tape (8-mm)
Digi-Data Corporation GIGA Store (VHS)
ExaByte EXB-8200 (8-mm)
If you've had experience with any of these products (or any OTHER
high-capacity tape systems), could you please send me your comments (or at
least try to answer some of the questions that follow).
I've obtained the reviews about ExaByte drives from back issues of
comp.sys.sun's sunspots (Anon FTP from titan.rice.edu). The information
is very helpful. As I mentioned, however, I'm not sure that we will be
able to go with that product, as it's cost is higher than other 8mm
systems.
As for general criteria concerning hi-cap tape systems, here's what we
came up with while considering a system:
1) VHS tape vs 8mm tape systems: How do they compare? We only have
info on one VHS system (GIGA Store). It seems to have a lower
error rate (1 bit/10^23 vs the 1 bit/10^24 of the 8mm systems).
The data transfer rate is slower in this VHS system (about 2 times
slower than 8mm systems). It holds about .5 Gb more than the
8mm's.
2) SCSI vs Pertec vs other drive interfaces. What's the most flexible?
The Sun's obviously are hardwared towards SCSI. There exists a
SCSI board for Qbus/Unibus of the VAX. What's the deal with
Pertec?
3) Recoverable errors vs Non-Recoverable errors. What's the difference?
Some of the brochures mention Error Correcting Code (ECC) and
recoverable/non-recoverable errors. How does this relate to the
hard error rate of the device? What's the error rate on say a DEC
TU80 1600 bpi 9-track tape drive?
4) Buffer size. What difference would a 256K buffer make vs. a 512K
buffer? Most of the systems we've seen have a 256K buffer.
5) (yuck, afraid to ask this one) Softare Drivers. How easy is it to
change over your system (Vax VMS/Sun OS 3.5) to the new device?
Are there major changes to the way the tape utilities (BACKUP/tar)
work?
6) (last but not least) Price. The ones we've seen have ranged from
$5000 - $7000. Do any companies offer educational discounts?
Please send replies to manager@a.coe.wvu.wvnet.edu as I will summarize to
the net. I am very appreciative of the knowledge that one can gain from
the net, and I feel obliged to put back as much as I take (plus I have to
report this information to my boss, so, why not give a copy to the net!)
-Cris
Cris Fuhrman, Systems Manager
WVU College of Engineering
Morgantown WV 26506-6101
internet: manager@a.coe.wvu.wvnet.edu
bitnet:....manager%wvucoe@wvnvms