From: Al Boldi <a1426z@gawab.com>
To: Marr <marr@flex.com>
Subject: Re: Readahead value 128K? (was Re: Drastic Slowdown of 'fseek()'
Date: Mon, 13 Mar 2006 14:37:50 +0300
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Marr wrote:
> The 2.6.13 kernel on ReiserFS (without using 
> 'nolargeio=1' as a mount option) still takes about 4m35s to fseek 200,000 
> times on that 4MB file, even with 'hdparm -a0 /dev/hda' in effect.

try this magic number:

        echo 192 > /sys/block/hda/queue/max_sectors_kb
        echo 192 > /sys/block/hda/queue/read_ahead_kb

Anything outside 132-255 affects throughput negatively.

Also, can you dump hdparm -I /dev/hda?

Thanks!

--
Al

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