On Mon, 31 May 2010, Sandon Van Ness wrote:
With sequential writes I don't see how parity writing would be any
different from when I just created a 20 disk zpool which is doing the
same writes every 5 seconds but the only difference is it isn't maxing
out CPU usage when doing the writes and and I don't see the transfer
stall during the writes like I did on raidz2.
I am not understanding the above paragraph, but hopefully you agree
that raidz2 issues many more writes (based on vdev stripe width) to
the underlying disks than a simple non-redundant load-shared pool
does. Depending on your system, this might not be an issue, but it is
possible that there is an I/O threshold beyond which something
(probably hardware) causes a performance issue.
GraphicsMagick Maintainer, http://www.GraphicsMagick.org/
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