Messages in this thread | | | Date | Tue, 17 Oct 2000 09:21:00 -0700 (PDT) | From | Andre Hedrick <> | Subject | Re: New Benchmark tools, lookie looky........ |
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On Tue, 17 Oct 2000, Larry McVoy wrote:
> On Tue, Oct 17, 2000 at 11:23:30AM +0200, Vojtech Pavlik wrote: > > Well, I know quite well what this can bring us - with precise profiling > > we could see the exact geometry of the drive > > LMbench has had something which does this for years. Look at > > http://www.bitmover.com/bw.gif > http://www.bitmover.com/seek.gif
Great, but that was via a file system.
> The first shows you zone bandwidths, the second shows you a precise profile > of the access times; you can get everything you might want from that. > For example, the time quoted by all the drive people is 1/3 in from the > left, at the bottom of the curve - a fairly misleading number if you ask > me.
> Bingo. Screwing around with the elevator is in general a waste of time, > but it is a rite of passage for all I/O people. I did it a long time
Well let me drown!
> ago and learned an important lesson: if your file system is good enough > (and most are) there is almost nothing that can be done to improve > performance - the file system has done all the work already. You're > welcome to argue that point, but please do so with traces of a real > system - not with your opinion. My opinion used to be the opposite > and the traces moved me to this opinion.
Expand 'traces' ... O-SCOPE analyizer?
How can LMbench access things that I can but a FS can not?
Andre Hedrick The Linux ATA/IDE guy
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