On Tue, 26 Jun 2007, Justin Piszcz wrote:

On Tue, 26 Jun 2007, Jon Nelson wrote:

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On Tue, 26 Jun 2007, Justin Piszcz wrote:

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On Tue, 26 Jun 2007, Jon Nelson wrote:

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On Mon, 25 Jun 2007, Justin Piszcz wrote:

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Neil has a patch for the bad speed.

What does the patch do?

I repeat: what does the patch do (or is this no longer applicable)?

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sync_speed_max defaults to 200000 on this box already.

Altering sync_speed_min...

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I tried a binary search of values between the default (1000)
and 60000 which resulted in some pretty weird behavior:

at values below 26000 the rate (also confirmed via dstat output) stayed
low.  2-3MB/s.  At 26000 and up, the value jumped more or less instantly
to 70-74MB/s. What makes 26000 special? If I set the value to 20000 why
do I still get 2-3MB/s actual?

Sounds quite strange, what chunk size are you using for your RAID?

The default: 64

md0 : active raid5 sdc4[2] sda4[0] sdb4[1]
      613409664 blocks level 5, 64k chunk, algorithm 2 [3/3] [UUU]


--
Jon Nelson [off-list ref]