poor performance on big machine

Matthew Dillon dillon at apollo.backplane.com
Mon Jul 30 10:04:06 PDT 2007


:more data:
:
:- irq21 seems to always carry about half of the number of interrupts atapci1 is carrying.
:
:- over large periods, the % busy of ad6 is at 100%, servicing maybe 350 or even 800 requests/sec.  I/O speed then is around 3-10 MB/sec.  this is with 1.10 and SMP.  I'll try compiling a old-ata kernel now.
:
:cheers
:  simon

    I don't think an I/O scheduler will help.  You are maxing out the hard
    drive with your workload.  MB/sec is irrelevant... the workload is 
    causing the disk to seek a lot.

					-Matt
					Matthew Dillon 
					<dillon at backplane.com>





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