Poor Performance on Solaris 11.1 to 11.3 using Emulex 8Gbps FC
Problem
The performance of ZFS I/O requests is poor when using Emulex 8Gbps FC.
Solution
This is a known issue on Oracle Solaris that has been permanently fixed in Oracle Solaris 11.3.4.5.0 (or greater). Oracle has documented a workaround which you can find in Doc ID 2100829.1 on the Oracle support site.