HP has changed there best practice for using there 3PAR StoreServ Storage systems when using Round Robin multi-pathing policy.
The old recommandation was to use IOPS=100, and this has changed to IOPS=1. so for setting this you should use the following.
3PAR runninng Persona 6:
esxcli storage nmp satp rule add -s "VMW_SATP_DEFAULT_AA" -P "VMW_PSP_RR" -O iops=1 –c "tpgs_off" -V "3PARdata" -M "VV" -e "HP 3PAR Custom iSCSI/FC/FCoE Rule"
3PAR running Persona 11:
esxcli storage nmp satp rule add -s "VMW_SATP_ALUA" -P "VMW_PSP_RR" -O iops=1 -c "tpgs_on" -V "3PARdata" -M "VV" -e "HP3PAR Custom iSCSI/FC/FCoE ALUA Rule"
See also dokuments from HP: White Pape: HP 3PAR StoreServ Storage and VMware vSphere 5 Best Practices
For HP EVA you should use:
esxcli storage nmp satp rule add –s VMW_SATP_DEFAULT_AA –P VMW_PSP_RR –o iops –O iops=1 –c tpgs on –V HP –M HSV300 –e “Custom rule name”