Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!think.com!spool.mu.edu!uunet!decwrl!world!lmh
From: lmh@world.std.com (Larry M Headlund)
Newsgroups: comp.sys.hp
Subject: Slow 9144 tape
Summary: Suggestions to speed 9144 access
Keywords: hp-ib 9144
Message-ID: <1991May24.162949.22189@world.std.com>
Date: 24 May 91 16:29:49 GMT
Article-I.D.: world.1991May24.162949.22189
Followup-To: request from jkrause@coral.whoi.edu
Distribution: ne
Organization: The World
Lines: 35


I tried to mail this to jkrause@coral.whol.edu but got a bounce.

Assuming your /dev/rct looks something like 

crw-rw-rw-   2 root     root       4 0x070300 May 22 10:21 /dev/rct

you are using the slow hp-ib commection.  This has two effects:

	1.	Tape operations do not interfere with disc i/o on the 
		"fast" hp-ib (0x0ennnn)

	2. 	Tape operations are very slow.

	If you have a fast hp-ib (if your disks are hp-ib you probably do)
then daisy chain your tape of of the fast hp-ib,  setting select codes 
appropriately.  Then two things will happen:

	1.	Tape speed will greatly improve

	2.	Tape access will degrade disc performance (TANSTAFL)

	For back up commands I have always had success with 

	find <dir list> -depth -print | cpio -oxv |tcio -o /dev/rct


	and recover with 

	tcio -i /dev/rct |cpio -ixvd