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From Peter Schuller <>
Subject Re: Does "concurrent_reads" relate to number of drives in RAID0?
Date Fri, 18 Mar 2011 00:29:20 GMT
> The comment in the example config file next to that setting explains it more
> fully, but something like 16 * number of drives is a reasonable setting for
> readers. Writers should be a multiple of the number of cores.

In addition, if you're running on Linux in a situation where you're
trying to saturate I/O capacity of an underlying device that is an SSD
or a multi-device RAID, I *strongly* suggest switching Linux to the
deadline or noop scheduler. The CFQ scheduler is very poor
out-of-the-box for saturating your I/O subsystem with random reads,
when using SSD:s or RAID controllers with multiple disks.

/ Peter Schuller

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