Path: utzoo!attcan!uunet!lll-winken!lll-tis!ames!amdahl!pacbell!varian!david
From: david@varian.UUCP (David Brown)
Newsgroups: comp.unix.microport
Subject: Re: Efficient tape I/O with 386/ix; How??
Summary: use -B
Keywords: streaming tape interactive slow
Message-ID: <701@varian.UUCP>
Date: 13 Dec 88 08:01:26 GMT
References: <317@focsys.UUCP>
Organization: Varian, Walnut Creek CA
Lines: 21

In article <317@focsys.UUCP>, larry@focsys.UUCP (Larry Williamson) writes:
> Streaming tape I/O with 386/ix seems to be rather slow.  The drive
> is not streaming very well.  It spends most of it's time stopping
> and starting.  I'm using an Everex Excel 60 with a long controller
> card. 
> 
> The command I've used is
> 	find . -print | cpio -ovc >/dev/rmt0
> 
I use an AT&T 6386, but I've heard that the UNIX sold by AT&T for the
6386 passed through Interactive.  I've gotten much enhanced performance
by using the -B flag to cpio:
 	find . -print | cpio -ovcB >/dev/rmt/c0s0

The difference (on an external Mountain 60mb (DC600A) drive) was something
like 45min vs. 4 hours for a full tape.  It still sounds like it's
stopping and starting a lot, though.

-- 
David Brown	 415-649-4000
Orion Network Systems 1995 University Ave. Suite 350 Berkeley CA 94704
{pacbell,lll-crg,zehntel,ista,rtech,csi,kinetics}!varian!david