Path: utzoo!utgpu!watserv1!watmath!att!dptg!lzsc!hcj
From: hcj@lzsc.ATT.COM (HC Johnson)
Newsgroups: comp.unix.i386
Subject: Re: Compressing to a tape drive
Summary: try obs=512b
Message-ID: <1383@lzsc.ATT.COM>
Date: 9 Mar 90 19:46:28 GMT
References: <14496@s.ms.uky.edu>
Distribution: na
Organization: AT&T BL Middletown/Lincroft NJ USA
Lines: 19

In article <14496@s.ms.uky.edu>, acp@ms.uky.edu (ACPNET consultant) writes:
> This is on an AT&T 6386 WGS running Sysv/386 3.2.1.
> 
> find . -print | cpio -oc | compress | dd [blocking options] > /dev/rmt/c0s0
> 
> Now, including dd in the pipe is *loads* faster than not including
> it, but I haven't been able to find any dd options which let the 
> tape stream.  It keeps stopping and backing up.  When using something

If you want your tape to screem ( in bursts) try:
dd of=/dev/rmt/c0s0 of=512b
this will output 512 BLOCKS of 512 at a time.  The tape will run continuously
for the big write, then rest while the buffer is refilled by the input to dd.


Howard C. Johnson
ATT Bell Labs
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hcj@lzsc.att.com