If you use MPXIO on your Solaris servers to multiplex I/Os over one or more HBAs, it is often valuable to view the I/O distribution on a per HBA basis. This is easily accomplished with the iostat “-X” option:
$ iostat -zxnXM 5
extended device statistics
r/s w/s Mr/s Mw/s wait actv wsvc_t asvc_t %w %b device
1170.6 0.0 146.3 0.0 0.0 1.4 0.0 1.2 1 98 c4t6006016061B71000AD0810C9979CD911d0
585.4 0.0 73.2 0.0 0.0 0.0 0.0 0.0 0 0 c4t6006016061B71000AD0810C9979CD911d0.fp0
585.2 0.0 73.2 0.0 0.0 0.0 0.0 0.0 0 0 c4t6006016061B71000AD0810C9979CD911d0.fp1
extended device statistics
r/s w/s Mr/s Mw/s wait actv wsvc_t asvc_t %w %b device
1175.2 0.0 146.9 0.0 0.0 1.3 0.0 1.1 1 98 c4t6006016061B71000AD0810C9979CD911d0
587.6 0.0 73.4 0.0 0.0 0.0 0.0 0.0 0 0 c4t6006016061B71000AD0810C9979CD911d0.fp0
587.6 0.0 73.4 0.0 0.0 0.0 0.0 0.0 0 0 c4t6006016061B71000AD0810C9979CD911d0.fp1
In this example we can see that the Solaris host (a Fujitsu 250 w/ two Emulex 9802s) was able to push almost 150 MB/s to our storage array (a Clariion CX500), and was balancing I/O evenly across both adaptors. Nice!