Poor SCSI drive performance on SMP machine, 2.2.16
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It sounds to me like you have a SCSI bus problem. Have you checked termination? Cable quality? Cable lengths?
Forgive me, I'm rather ignorant of SCSI hardware.....All that I have is a cable (appears
to be good quality, came with motherboard) about 60 centimeters long going from the
motherboard to my hard drive. There is an unused/empty port in between.
Quoted 5 lines
Do you have tagged queuing enabled for aic7xxx? It's a config option and you can adjust the maximum queue depth. You can see the current settings by cat
/proc/scsi/aic7xxx/0
/proc/scsi only contains a single file named "scsi" with brief info about the drive
According to my last save kernel config, tagged command queueing is not enabled by default.
Could this be the problem?
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Do you have write caching enabled on the drive? scsiinfo -c
/dev/sdxwill tell you if you do.
I don't seem to have scsiinfo.
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As a data point, I copied a 650MB file to another file on the same 10krpm disk and sync'ed in about the same time it takes you to write 100MB. I've also copied it from a slower 7200rpm disk to my 10krpm IBM drive and sync'ed in 1 min 19 secs which is about the read speed of the slower disk.
--
Trevor Hemsley, Brighton, UK.
[email protected]
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