From mboxrd@z Thu Jan  1 00:00:00 1970
From: linux@horizon.com
Subject: Re: Interesting RAID checking observations
Date: 21 Sep 2006 02:58:08 -0400
Message-ID: <20060921065808.19682.qmail@science.horizon.com>
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Just to follow up my speed observations last month on a 6x SATA <-> 3x
PCIe <-> AMD64 system, as of 2.6.18 final, RAID-10 checking is running
at a reasonable ~156 MB/s (which I presume means 312 MB/s of reads),
and raid5 is better than the 23 MB/s I complained about earlier, but
still a bit sluggish...

md5 : active raid5 sdf4[5] sde4[4] sdd4[3] sdc4[2] sdb4[1] sda4[0]
      1719155200 blocks level 5, 64k chunk, algorithm 2 [6/6] [UUUUUU]
      [=>...................]  resync =  6.2% (21564928/343831040) finish=86.0min speed=62429K/sec

I'm not sure why the raid5 check can't run at 250 MB/s (300 MB/s disk
speed).  The processor is idle and can do a lot more than that:

raid5: automatically using best checksumming function: generic_sse
   generic_sse:  6769.000 MB/sec
raid5: using function: generic_sse (6769.000 MB/sec)


But anyway, it's better, so thank you!  I haven't rebooted the celeron
I hung for the duration of a RAID-1 check, so I haven't checked that with
2.6.18 yet.