flur@eecom.gatech.edu (Peter W. Flur) (04/11/91)
I am using an exabyte attached to a Sun for dumps of several different types of machines
on our network including Suns, NeXT's, Dec's, and HP workstations. When I dump from a
Sun to the dump host (a Sun), every thing works great and the transfer is blazingly
quick. However, when I do a dump from a NeXT (running 1.0a) or one of the HP workstations
(running HP/UX), the dump works, but it is noticeably slower than dumping another Sun
with larger disks. For example, a full dump of a NeXT with a 330MB (280MB used) drive
takes roughly (these are estimates but close in magnitude) 45-60 minutes. A Sun with a
660MB drive (270MB used) takes less than 15 minutes. Both machines are dumped from the
tape host through a shell script as follows:
rsh workstation rdump 0nubsdf 1024 6000 54000 tapehost:/dev/exabyte /partition
where the obvious substitutions are made with the appropriate names.
Can anyone offer a reason why these other machines are significantly slower than the
suns, and more importantly, can someone offer a solution to speed them up?
Thanks,
Peter
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Peter Flur, Research Engineer
Georgia Institute of Technology
School of Electrical Engineering, Atlanta, GA 30332-0250
E-MAIL: flur@ee.gatech.edu
PHONE: (404) 853-9355
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DUKE UNIVERSITY
1991 NCAA BASKETBALL CHAMPIONS!!!scs@iti.org (Steve Simmons) (04/11/91)
flur@eecom.gatech.edu (Peter W. Flur) writes: >I am using an exabyte attached to a Sun for dumps of several different >types of machines on our network including Suns, NeXT's, Dec's, and HP >workstations. >Can anyone offer a reason why these other machines are significantly slower >than the suns, and more importantly, can someone offer a solution to speed >them up? Several reasons. First, dumps across a network are going to have more overhead than direct attach. So the odds are real good that any bottleneck anywhere will hurt you big time. Second, the quality of implementation of dump varies wildly from system to system. At one time there was a quite quick one available for anon ftp, but I've not been able to find it recently. -- "Our informal mission is to improve the love life of operators worldwide." Peter Behrendt, president of Exabyte. Quoted in Digital Review, Feb 4, 1991.