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- Newsgroups: comp.unix.sysv386
- Path: sparky!uunet!gator!dlpinc00!dlparker
- From: dlparker@dlpinc00.rn.com (David L. Parker)
- Subject: Re: Tape drive streaming magic for ISC
- Message-ID: <1992Dec17.011258.1228@dlpinc00.rn.com>
- Organization: Automated Data Management Services
- References: <1992Dec14.153909.9982@rocker.uucp>
- Date: Thu, 17 Dec 1992 01:12:58 GMT
- Lines: 35
-
- In article <1992Dec14.153909.9982@rocker.uucp> doug@rocker.uucp (Doug Luecke) writes:
- >I have recently added a Jumbo 250 tape drive to my 386/40 running ISC 2.0
- >Unix (SVR3), using the Colorado Unix/Xenix tape driver and jtape software.
- >The Jumbo 250 is a QIC-80 tape drive that uses 2120 tapes.
- >
- >Everything works fine except the tape drive doesn't seem to be streaming,
- >causing the backups and restores take from five to ten times as long as the
- >time estimate indicates they should. (This is also about five to ten times
- >as long as the equivalent backup takes on my DOS machine with the same
- >drive.) The darn thing spends more time repositioning than reading or
- >writing data.
- >
- >The manual says nothing about tuning the software to get the drive to stream.
- >I've tried nice'ing the jtape program with -20, but it made no difference.
- >There's basically nothing else going on when I'm doing the backup.
- >
- >Is there some way to tweak the driver or something magic to do to get the
- >drive to stream? I'd really appreciate any help on this.
- >
- >doug
- >--
- >Doug Luecke UUCP: uunet!iex!rocker!doug
- >Terzon Systems, Inc. INTERNET: iex!rocker!doug@uunet.uu.net
- >Richardson, Texas MABELL: 214/234-8222
-
- I'm not familiar of any method of improving the performance of these drives
- other than using the TC-15 h'ware compression controller. If you're running
- off the floppy controller, you'll notice a dramatic improvement. Wish I had
- figures to give you, but I no longer run my DJ-20/TC-15 under UNIX, and didn't
- save any comparative data. The FC-10 controller is quite an improvement over
- the floppy interface, too, but again, no hard data.
- --
- Dave Parker
- Automated Data Management Services, Pleasant Hill, MO 64080-1331
- (816) 987-5167/5218 voice/fax - dlparker@dlpinc00.rn.com
-