[Bioclusters] Tool to benchmark disk IO?

Dan Bolser bioclusters@bioinformatics.org
Fri, 24 Sep 2004 19:21:35 +0100 (BST)

On Fri, 24 Sep 2004, elijah wright wrote:

>not sure that it will work over nfs.  probably not.  but you probably need 
>to tweak local disk performance before you worry about NFS anyway.

Thanks for this, a preliminary test in an NFS directory gave me

Seeker 1...Seeker 3...Seeker 2...start 'em...done...done...done...
              -------Sequential Output-------- ---Sequential Input--
              -Per Char- --Block--- -Rewrite-- -Per Char- --Block---
Machine    MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU  /sec %CPU
          100  4240 25.9  5437  2.1  4780  2.4 19595 100.1 566942 99.7 2023.0 10.1

With default file size (104857600). The CPU is 'amazingly high' during

Not sure what you mean about tweeking local disk performance. Can you
explain why this is a factor when I work mostly on NFS directories?

Thanks again,

>> Hi, I have checked the archive, but I can't find any reference to a simple
>> IO 'tester' app to benchmark disk IO.
>> I am fairly sure it would be easy to write a little tool to do this. Has
>> anyone done that?
>> I would like to be able to say things like
>> ioRateTool --test-file /IDEDiskMount/testFile.scratch
>> ioRateTool --test-file /SCSIDiskMount/testFile.scratch
>> ioRateTool --test-file /NFSDiskMount/testFile.scratch
>> ioRateTool --test-file /ramfsDiskMount/testFile.scratch
>> ioRateTool --test-file /dev/null/testFile.scratch
>> Although I guess that last one could only measure 'disk' write speed and
>> not read speed.
>> I want to see if my current NFS settings can be optimized, and I would
>> like a clean (and hopefully robust) way to check what effect changing the
>> options have.
>> Thanks for any pointers,
>> Dan.
>> Ahhh... I just found the collective NFS rant...
>> We use NFS as our principal 'communication' channel, that is to say it is
>> our group sand box. We put all our downloaded databases / scripts / data /
>> homes on one big nfs server. This allows us to work on the same data
>> easily, share files / results etc.
>> Most of our 'day to day' computing is over this data.
>> How many Hail Mary's should I say?
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