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From: silver@s.cs.uiuc.edu
Newsgroups: comp.sys.ibm.pc.rt
Subject: Re: Can 6157-002 tape drive be forced t
Message-ID: <213600004@s.cs.uiuc.edu>
Date: 2 Nov 89 23:32:00 GMT
References: <3425@nmtsun.nmt.edu>
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Nf-ID: #R:nmtsun.nmt.edu:3425:s.cs.uiuc.edu:213600004:000:731
Nf-From: s.cs.uiuc.edu!silver    Nov  2 17:32:00 1989


Re: 6157-002 tape drives being slow

Yes, I agree they aren't speed-demons, but I have obtained a tremendous
speedup with buffering.  The daily backups we make (5-8Meg) take
only 4-5 minutes.  The fulldumps (200+Meg) take only 75-80 minutes.
That's not including the time to switch between the 4 tapes it requires.

All we changed in the cpio (daily) or backup (fulldump) calls was to
include -C2000 for a block/buffer size of 1 Meg.  We have 12 Meg. of
real memory, so page-faulting is not much of a problem.

As far as reading -001 tapes on a -002, I'd like to answer to that
if anyone ever discovers one.

All of this is from a RT/125 with 3x310 Meg disks (mostly empty).

Edward A. Silverstein
silver@director.beckman.uiuc.edu