The Emulex fiber channel device driver supports a max-xfer-size
tunable (via /kernel/drv/emlxs.conf) which only applies to i386.
This tunable specifies the scatter gather list buffer size. By
default, this value is set to 339968 for Solaris 10.
Today I experimented with doubling this value to 688128 and was happy
to see a large increase in sequential read performance from my ZFS
pool which is based on six mirrors vdevs. Sequential read performance
jumped from 552787 MB/s to 799626 MB/s. It seems that the default
driver buffer size interfers with zfs's ability to double the read
performance by balancing the reads from the mirror devices. Now the
read performance is almost 2X the write performance.
Bob
--
Bob Friesenhahn
bfrie...@simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer, http://www.GraphicsMagick.org/
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