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- Path: sparky!uunet!wupost!zaphod.mps.ohio-state.edu!moe.ksu.ksu.edu!news!brtmac
- From: brtmac@maverick.ksu.ksu.edu (Brett McCoy)
- Newsgroups: comp.sys.sun.admin
- Subject: Re: Exabyte 8500 Tapes
- Date: 7 Sep 92 22:51:37
- Organization: Kansas State University
- Lines: 30
- Message-ID: <BRTMAC.92Sep7225137@maverick.ksu.ksu.edu>
- References: <3217@peking.gdwb.oz.au> <pge9pm4@zuni.esd.sgi.com>
- <1992Sep7.092208.24633@comp.lancs.ac.uk>
- <6606@lhdsy1.lahabra.chevron.com>
- NNTP-Posting-Host: maverick.ksu.ksu.edu
- In-reply-to: shc@lhdsy1.lahabra.chevron.com's message of 8 Sep 92 02:45:31 GMT
-
- In article <6606@lhdsy1.lahabra.chevron.com> shc@lhdsy1.lahabra.chevron.com (S.H. Couturie) writes:
-
- >My experience, with hundreds of tapes on multiple 8500 drives on an Epoch,
- >is that the video grade tapes cause many write errors; some of the errors
- >are "soft", and have no apparent effect (and may not even be logged,
- >depending on your driver), but *do* drastically reduce both throughput
- >and tape capacity; other errors, the minority, are hard and will abort the
- >writes. We have switched to exclusive use of Sony "QG" data grade tapes,
- >with *no* errors recorded in months now. We have never had any trouble
- >*reading* either quality tape.
-
- I don't have quite that amount of experience, but I've been using an EXB8500
- for about a year now doing nightly backups of ~6G of total disk space (this
- typically amounts to about 1.5G of data dumped each night). I use Sony
- video grade cassettes and routinely get 480k/sec or better transfer rates.
- The max sustained rate that the drive is supposed to be able to manage is
- 500k/sec so I don't think there is a drastic reduction in throughput. Now,
- capacity is a different story. With the video grade cassettes I usually can
- only get a maximum of 4.3G - 4.5G on a tape, but since I very rarely dump
- that much at once it's no big deal. Maybe in the future when we get more
- disk space and dump more each night it might make a difference.
-
- >As for cost, our price for the Sony data grades, quantity 50, is now
- >less than $12/tape. I don't consider that excessive for the
- >reliability, consistent throughput and capacity.
-
- We haven't bought any new tapes for quite a while. I expect the next
- bunch of tapes we buy will probably be data grade.
-
- ++Brett;
-