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From: ral@cathedral.cerc.wvu.wvnet.edu (Rebecca A. Littleton)
Newsgroups: comp.sys.sgi
Subject: Slooow backups with BRU
Message-ID: <1022@babcock.cerc.wvu.wvnet.edu>
Date: 26 Nov 90 14:19:35 GMT
Sender: news@cerc.wvu.wvnet.edu
Lines: 28


	We are using the BRU command for backups on our SGI file
server onto a Kennedy Model 9610/9660 tape drive (1/2" magnetic 
reel-to-reel drive).  Backups are taking 1 hour to fill each tape
(150 M tape).  This is too slooow and not practical.
	If you are using BRU for backups onto reel-to-reel tapes,
does it take you this long?  If it doesn't, do you know what I
might change or what I might be doing wrong?  I have thought of:
(1) bad /etc/brutab entry.  I use the default supplied by SGI.
	/dev/rmt/xmt0d0.6250 | /dev/mt/xmt0d0.6250 \
		size=0K seek=0 \
		prerr=0 pwerr=0 zrerr=0 zwerr=0 frerr=0 fwerr=0 wperr=0 \
		reopen rawtape tape advance
	/dev/rmt/xmt0d0nr.6250 | /dev/mt/xmt0d0nr.6250 \
		size=0K seek=0 \
		prerr=0 pwerr=0 zrerr=0 zwerr=0 frerr=0 fwerr=0 wperr=0 \
		norewind reopen rawtape tape advance
(2) bad tape drive.  It checked OK on setup by SGI.
(3) BRU is inherently slow.
(4) porting the dump command (a la SunOS dump) to the SGI.

If you have increased the speed of BRU, how did you do it?  I would 
really appreciate knowing how I can speed up backups.  We have 5G of 
disk space on our SGI server and are currently using 14 tapes for a 
monthly backup.  HELP!!!