Hi, All, i have performance difficulties with a dual-opteron system : there is a scsi - megaraid controller with 4 harddrives configured as a raid 10. our database writes huge temp-files (up to 4GB). the feeling was - it`s slow. So i compared it with a similar 32-bit system: the 64-bit needed twice (!) the time to copy a 4GB -asciifile than the 32-bit system. i changed the raid-parameters (writeback to write through and some more) - no effect i changed the modules megaraid to megaraid2 - no effect what can i do to get it faster?? Mit freundlichen Grüßen Frank Schmitz config: 64-bit: tyan k8s with 2 amd opteron (246) 2 GHz 2GB RAM lsi megaraid u320 (64 MB) 4 drives 35 GB 10000rpm raid 10 ( means 2 x 2 drives raid 0, then raid 1) SuSE 9.0 x86_64; ext3, 32-bit: dual xeon 2 GHz lsi megaraid u320 (64 MB) 4 drives 35 GB 7200rpm raid 10 SuSE 8.2, ext3
On Fri, Jul 16, 2004 at 12:24:02PM +0200, Frank Schmitz wrote:
i have performance difficulties with a dual-opteron system : there is a scsi - megaraid controller with 4 harddrives configured as a raid 10. our database writes huge temp-files (up to 4GB). the feeling was - it`s slow. So i compared it with a similar 32-bit system: the 64-bit needed twice (!) the time to copy a 4GB -asciifile than the 32-bit system. i changed the raid-parameters (writeback to write through and some more) - no effect i changed the modules megaraid to megaraid2 - no effect
what can i do to get it faster??
Does the 32bit system use an megaraid too? megaraids are always quite slow compared to other RAID controllers. I also don't know of a way to make them faster. Software RAID with a simple SCSI controller is usually much faster. -Andi
Yes it's megaraid too. we have some gdt-systems (32-bit) too. they are faster, but not so significant ... I use one system with software-raid and normal scsi. when i write such a large file, the disc-system is blocked until the file is written. thats the reason for the dedicated raidcontroller. Mit freundlichen Gru?en Frank Schmitz Mit freundlichen Gru?en Frank Schmitz
-----Ursprungliche Nachricht----- Von: Andi Kleen [mailto:ak@suse.de] Gesendet: Freitag, 16. Juli 2004 13:55 An: Frank Schmitz Cc: suse-amd64@suse.com Betreff: Re: [suse-amd64] megaraid and write-performance
On Fri, Jul 16, 2004 at 12:24:02PM +0200, Frank Schmitz wrote:
i have performance difficulties with a dual-opteron system : there is a scsi - megaraid controller with 4 harddrives configured as a raid 10. our database writes huge temp-files (up to 4GB). the feeling was - it`s slow. So i compared it with a similar 32-bit system: the 64-bit needed twice (!) the time to copy a 4GB -asciifile than the 32-bit system. i changed the raid-parameters (writeback to write through and some more) - no effect i changed the modules megaraid to megaraid2 - no effect
what can i do to get it faster??
Does the 32bit system use an megaraid too?
megaraids are always quite slow compared to other RAID controllers. I also don't know of a way to make them faster. Software RAID with a simple SCSI controller is usually much faster.
-Andi
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participants (2)
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Andi Kleen -
Frank Schmitz