Joe, thanks for the link thought, i don't think the problem is only oracle related. I used oracle as a bench tool (and also because it will be the main part of the application these machines have to serve). Also, I (have to) use oracle 8.1.7 remember : the 2 machines have exactly the same oracle configuration, so the difference is quite for sure os-related (filesystems, memory config). I would hardly believe that a 2 way xeon with fwd scsi disks has lower performance than a pIV with a single ide disk my questions are for example : why is buffer storage so low ? what about special tuning options for xfs filesystems ? which tools could I use to compare latencies between the 2 machines and hopefully get some clues to where the problem lies ? or which tests should i do (how to bench an IO subsystem...) TIA A 11:11 02/12/2004 -0500, vous avez écrit : >Have you seen this: >http://www.puschitz.com/InstallingOracle9i.shtml > >There are links to tuning the kernel for faster Oracle. > > >On Thu, 02 Dec 2004 17:01:41, Thierry ITTY <thierry.itty@xxxxxxxxxxxx> wrote: >> I have 2 machines : >> - a mono-PIV with 512 MB, one 40 GB ide disk, RH9 2.4.20-8 and ext3 >> filesystems >> - a bi-Xeon with 2.5 GB, two 14 GB fwd scsi disks, RH9 >> 2.4.20-9SGI_XFS_1.2.0smp and xfs filesystems >> >> both have oracle 8.1.7.3 installed, with exactly the same database >> (export/import) >> >> we wrote a test script (timing a sql query executed 20 times) to compare >> performance on the 2 machines >> >> on the PIV machine the test runs in 0.8 seconds, and on the Xeon machine it >> takes 1.1 seconds (many many tests, these are really definitive values) >> >> I need some advice to investigate. >> >> I read about "bounce buffering", "asynchronous io", shmmax values, and so on, >> One clue is that on the Xeon machine, cat /proc/meminfo always show very >> little buffer usage (steady 60k) whereas on the other I've more than 100m. >> >> I can't find anything helpful to solve this performance issue >> >> any help greatly appreciated >> >> TIA -- redhat-list mailing list unsubscribe mailto:redhat-list-request@xxxxxxxxxx?subject=unsubscribe https://www.redhat.com/mailman/listinfo/redhat-list
