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From: k2@charly.bl.physik.tu-muenchen.de (Klaus Steinberger)
Newsgroups: comp.sys.mips
Subject: Re: Experience with DAT drives?
Message-ID: <1550@tuminfo1.lan.informatik.tu-muenchen.dbp.de>
Date: 28 Mar 90 12:11:57 GMT
References: <766@cluster.cs.su.oz> <1990Mar28.053504.14178@sobeco.com>
Sender: news@lan.informatik.tu-muenchen.dbp.de
Distribution: comp
Lines: 35

roe@sobeco.com (r.peterson) writes:

>From article <766@cluster.cs.su.oz>, by yar@cs.su.oz (Ray Loyzaga):
>> In article <1990Mar11.160020.27837@sobeco.com> roe@sobeco.com (r.peterson) writes:
>> the real win is that the tape can do end to end
>> seeks in 10-20 seconds, whereas the Exabyte is absolutely painful
>> with each command.

>Why is this a real win?  How many backup/restore utilities take
>advantage of seek time?  Who cares how fast a drive rewinds?
>Also, I should point out that the DAT drives can *not* perform
>block seeks from end to end in 20 seconds - they can search
>file marks this fast.

>We've set up our system to use exabytes in 100MB savesets;  worst-
>case restore time (the last file on the last saveset) is about
>18 minutes (forward space 19 files, read the balance, and grab the
>last file).

You are thinking that there is nothing that can be done with a
DAT or Exabyte besides the standard backup/restore tasks!

We want to use DAT's for Data-acquistion, and there is very much
pain if you need a long time for seeking your files. Also there
is very much pain if you need 15 Minutes to rewind your tape!

Also there is only one manufacturer for EXABYTE, namely EXABYTE.
The DAT's you can get from many suppliers. This is very important,
if you depend on the availability, say in 5 or 10 years!

Sincerely,
Klaus Steinberger
Klaus Steinberger               Beschleunigerlabor der TU und LMU Muenchen
Phone: (+49 89)3209 4287        Hochschulgelaende, D-8046 Garching, West Germany
BITNET:  K2@DGABLG5P            Internet: k2@charly.bl.physik.tu-muenchen.de