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From: wescott@Columbia.NCR.COM (Mike Wescott)
Newsgroups: ncr.sys.unix,comp.sys.ncr
Subject: Re: Copying from one tape to another tape
Keywords: cpio, tar, dd
Message-ID: <1891@sauron.Columbia.NCR.COM>
Date: 14 Jan 90 03:47:24 GMT
References: <812@pmday_2.Dayton.NCR.COM>
Sender: news@sauron.Columbia.NCR.COM
Reply-To: wescott@micky.Columbia.NCR.COM (Mike Wescott)
Distribution: usa
Organization: E&M-Columbia, NCR Corp, W Columbia, SC
Lines: 23

In article <812@pmday_2.Dayton.NCR.COM> steve@pmday_2.Dayton.NCR.COM (Steve Bridges) writes:
> cpio -idmuvcB < /dev/rtp | cpio -ocvB > /dev/rtp1

What this command line says is "read /dev/rtp and let cpio dearchive (put on
disk) all the files it finds there spitting out the file names as it goes.
The second cpio reads those file names and recreates the archive on /dev/rtp1.

> Would  cpio -idmuvcB < /dev/rtp > cpio -ocvB > /dev/rtp1
> do what I want without putting a copy on disk?

Nope. Not even valid syntax.  You can't redirect stdout twice on the same
command.  The command that the shell parses out looks just the same as:

	cpio -idmuvcB -ocvB < /dev/rtp > cpio > /dev/rtp1

Your best bet is plain old dd(1):

	dd if=/dev/rtp of=/dev/rtp1 bs=100k

should do the trick with reasonable efficiency.
--
	-Mike Wescott
	 mike.wescott@ncrcae.Columbia.NCR.COM