From: Goswin von Brederlow <goswin-v-b@web.de>
To: linux-raid <linux-raid@vger.kernel.org>
Subject: Odd raid5 reshape behaviour
Date: Wed, 25 Nov 2009 11:09:23 +0100 [thread overview]
Message-ID: <874ooiq5kc.fsf@frosties.localdomain> (raw)
Hi,
I'm reshaping a raid5 from 3 to 4 disks and I'm seeing something odd.
md2 : active raid5 sda3[3] sdd3[2] sdc3[1] sdb3[0]
2832114688 blocks super 0.91 level 5, 64k chunk, algorithm 2 [4/4] [UUUU]
[==============>......] reshape = 73.2% (1037811200/1416057344) finish=276.4min speed=22802K/sec
Device: tps kB_read/s kB_wrtn/s kB_read kB_wrtn
sda3 792.90 0.00 27459.20 0 274592
sdb3 433.70 0.00 27459.20 0 274592
sdc3 393.20 0.00 27459.20 0 274592
sdd3 399.10 0.00 27458.80 0 274588
The reshape has copied all the old stripes to new positions and now I
guess it fills the drives with zeroes for the remainder.
But why are they roughly twice as many tps on sda, which is the new
disk? All drives write the same amount of data but sda seems to write
it in twice as many chunks.
MfG
Goswin
reply other threads:[~2009-11-25 10:09 UTC|newest]
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