tyager@mkunix.DEC.COM (Tom Yager) (02/03/88)
Someone posted something here earlier asking about "cheap" tape drives.
I bought the Irwin 40Mb internal drive to go with my MDS 20MHz '386 &
SCO; here's my impressions:
(first, the bad news...)
MINUSES:
o The drive is not compatible with the 'tape' utility (and SCO says it
probably never will be).
o It won't run on most 20MHz '386 boxes--SCO admits the problem is in
the device driver and they plan to address it "shortly." I solved
this by replacing my 40MHz crystal with a 32.??? MHz one. When they
fix the driver, I'll boost it again (a noticable difference!).
o Tapes need to be formatted and verified before they can be used. A
tape formatted under MSDOS using Irwin's utilities can't be used under
SCO. Format/verify is NOT a quick procedure--I think it's over 30
minutes, but I can't recall for certain. I'll post timings for anyone
who's interested (mail me).
o The driver is a real memory hog. If you're running on a minimum memory
system (i.e. 1 meg), you might not be able to do backups in multi-user
mode. There's a good reason for this (see below).
PLUSES:
o It's the cheapest 40Mb tape drive I've seen (of the ones that can be
used with SCO, that is).
o It is FAST. Again, I'll post timings if I get enough mail, but believe
me: it's more than adequate backup for my system which has 90MB of hard
disk.
o The small (DC2000) tapes are nice. Easy to carry, mail, store, etc.
o The driver will allocate a huge buffer for the device so that data is
shipped to the drive "nearly streamed," that is, much fewer
write-stop-reverse-stop-read-stop-etc...
o A separate device special file, "/dev/rctminiv" (as opposed to just
"rctmini") verifies the tape write with a readback. It seems to be
just a readability check and not a verify against the original data,
but it's enough. The ECC takes care of the rest.
o I think it's the easiest to install: plug it in as floppy drive B and
slide it in! I was able to install mine without messing with a single
jumper or DIP switch or even CMOS setup.
o The pre-format and verify, pain though it is, seems to work. I have
done dozens of backups since I originally installed the drive and
have not had a single read/write failure.
o The DOS software Irwin provides is quite good and allows for multiple
archives on a single tape. It has both menu-driven and command line
interfaces. It's interactive mode is nice and fashioned similar to
"Xtree".
o I've used tar, dump, restore, and cpio with no problems, and used them
all while in multi-user mode.
I'm anticipating that there will be those who feel moved to respond
to this by defending whatever drive they chose. I'm not beating down any
other product, and I haven't personally tried any other drive. I just
know that the Irwin works reliably, is supported well under SCO, and
can be afforded by people who still insist on daily feedings.
--
Tom Yager, Digital Ultrix Support ("It MUST be the hardware!")
U.S. Mail: DEC, 14 Walkup Drive YWO/C9, Westborough, MA 01581
uucp: ...decvax!mkunix!tyager
"Eat a live toad in the morning; nothing worse will happen all day."wrp@biochsn.acc.virginia.edu (William R. Pearson) (02/03/88)
I would appreciate a quick summary of tape backup solutions that work with Xenix (286 or 386). Although I see discount 60 Mbyte tape drives for sale for around $750, it is not clear that they will work with Xenix tape drivers. And if they do, will they also interchange with a Sun3/50 tape drive? The only tape drive that is guaranteed to do this that I know of comes from Bell Technologies for around $1500. Bill Pearson wrp@virginia
wrm@pnet02.cts.com (William Mattil) (02/06/88)
wrp@biochsn.acc.virginia.edu (William R. Pearson) writes: >I would appreciate a quick summary of tape backup solutions that >work with Xenix (286 or 386). Although I see discount 60 Mbyte >tape drives for sale for around $750, it is not clear that they >will work with Xenix tape drivers. And if they do, will they >also interchange with a Sun3/50 tape drive? The only tape drive >that is guaranteed to do this that I know of comes from Bell >Technologies for around $1500. > >Bill Pearson >wrp@virginia While it is unclear what type of hardware you want to use the tape drive with, I'll assume its Intel based, '286 | '386. I use an Archive FT-60 external tape drive under Xenix '286 release 2.2 and it functions very well with the supplied driver from SCO. In the past 2 years, I have had no trouble with this drive ( or drivers ) except for cleaning the mechanism perodically. The mail order prices on this system are reasonable as well. I hope this helps. disclaimer: I am not associated with Archive in any capacity, just a satisfied customer. Regards Bill UUCP: {ihnp4!scgvaxd!cadovax rutgers!marque}!gryphon!pnet02!wrm UUCP: {hplabs!felix, crash}!telcomm!wrm INET: wrm@pnet02.cts.com
romwa@gpu.utcs.toronto.edu (Mark Dornfeld) (02/16/88)
I have a couple Archive 60Mb drives running and have had few problems, but we do not back up daily. Our drivers are from Consensys and allow allocation of really large buffers. On one 386 I use 4000 blocks of memory to buffer the process. This speeds things up incredibly. I saw a tape drive from Tandberg Siemans at Consensys booth at Uniforum. Both Consensys and Jasmine (with peripherals for the Mac II under UNIX) like the T-S drive (125 Mb). Mark T. Dornfeld Royal Ontario Museum utgpu!rom!mark - or - utgpu!romwa