*BSD News Article 2871


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Path: sserve!manuel!munnari.oz.au!hp9000.csc.cuhk.hk!uakari.primate.wisc.edu!sdd.hp.com!usc!rpi!utcsri!torn!watserv2.uwaterloo.ca!watserv1!mks.com!fredw
From: fredw@mks.com (Fred Walter)
Newsgroups: comp.unix.bsd
Subject: Getting tapes to stream (was Re: What kind of tape is OK w/ 386BSD?
Message-ID: <1992Jul31.161715.12462@mks.com>
Date: 31 Jul 92 16:17:15 GMT
References: <28JUL199218203085@stars.gsfc.nasa.gov> <1992Jul29.161438.6372@mks.com> <55595@mentor.cc.purdue.edu>
Organization: Mortice Kern Systems Inc., Waterloo, Ontario, CANADA
Lines: 18

mm@mentor.cc.purdue.edu (Mike MacKenzie) writes:
>I have a Wangtek 5150ES SCSI-36 tape drive and it works, but slowly.
>It took over 12 hours to back up ~80 meg.  I've tried various buffer
>sizes with dd with no improvment.

Wow, 12 hours ? What sort of hardware (386 ?) and how fast is it ?
My Wangtek 5150EQ wasn't able to stream, but it didn't take that long...

You could try 'ddd'. I don't recall where it can be found; probably on
ftp.uu.net somewhere. It works by having two processes, one filling up a
buffer whilst the other writes a buffer out; that way the tape drive always
is being fed a buffer (no pauses while the buffer dd uses is refilled).
Or some such thing.

	fred
-- 
Disclaimer: everything I write is my *personal* opinion and does not represent
or reflect the opinion of the company which employs me.