From: Sebastian Kuzminsky <seb@highlab.com>
To: linux-raid@vger.kernel.org
Subject: Raid sync observations
Date: Tue, 20 Dec 2005 10:18:26 -0700 [thread overview]
Message-ID: <E1Eol86-0008Ju-3J@highlab.com> (raw)
I just created a RAID array (4-disk RAID-6). When "mdadm -C" returned,
/proc/mdstat showed it syncing the new array at about 17 MB/s. "vmstat 1"
showed hardly any blocks in or out, and an almost completely idle cpu.
Question 1: Why didnt the raid sync I/O show up with vmstat?
Question 2: Why was it limited to 17 MB per second? The maximum was
left at the default, 200 MB/s. The min was also at the default, 1 MB/s.
I get 60 MB/s per disk with "hdparm -tT" (that's using one disk at a time,
but still). The checksumming code does > 3 GB/s.
Just curious really. This is with 2.6.15-rc5 and SATA disks via libata.
--
Sebastian Kuzminsky
next reply other threads:[~2005-12-20 17:18 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-12-20 17:18 Sebastian Kuzminsky [this message]
2005-12-20 18:14 ` Raid sync observations Sebastian Kuzminsky
2005-12-20 21:27 ` Neil Brown
2005-12-20 21:33 ` Sebastian Kuzminsky
2005-12-21 1:55 ` Christopher Smith
2005-12-21 11:49 ` Andy Smith
2005-12-21 17:02 ` Sebastian Kuzminsky
2005-12-21 17:13 ` Gordon Henderson
2006-01-08 18:18 ` Bill Davidsen
-- strict thread matches above, loose matches on Subject: below --
2005-12-20 18:27 Andrew Burgess
2005-12-20 19:13 ` Sebastian Kuzminsky
2005-12-20 22:09 Jeff Breidenbach
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