On Fri, 7 May 2010, Michael Sullivan wrote:
Well, if you are striping over multiple devices the you I/O should be spread
over the devices and you
should be reading them all simultaneously rather than just accessing a single
device. Traditional
striping would give 1/n performance improvement rather than 1/1 where n is the
number of disks the
stripe is spread across.
This is true. Use of mirroring also improves performance since a
mirror multiplies the read performance for the same data. The value
of the various approaches likely depends on the total size of the
working set and the number of simultaneous requests.
Currently available L2ARC SSD devices are very good with a high number
of I/Os, but they are quite a bottleneck for bulk reads as compared
to L1ARC in RAM .
Bob
--
Bob Friesenhahn
bfrie...@simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer, http://www.GraphicsMagick.org/
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