Setting up proper multiple active I/O Paths between ESX and Equalogic

There are two options:

1. If ESX Enterprise license is available, download Dell MEM 1.1.2 package from the Equallogic support website

2. If ESX Enterprise license is not available, run this script to set all EQL volumes to Round Robin and set the IOPs value to 3 (from the default of 1000):

esxcli storage nmp satp set --default-psp=VMW_PSP_RR --satp=VMW_SATP_EQL ; for i in `esxcli storage nmp device list | grep EQLOGIC|awk '{print $7}'|sed 's/(//g'|sed 's/)//g'` ; do esxcli storage nmp device set -d $i --psp=VMW_PSP_RR ; esxcli storage nmp psp roundrobin deviceconfig set -d $i -I 3 -t iops ; done

After you run the script you should verify that the changes took effect.
#esxcli storage nmp device list

For best performance you should also DISABLE delayed ack and Large Receive offload (LRO) on the ESX nodes:
# esxcfg-advcfg -s 0 /Net/TcpipDefLROEnabled
NOTE: a server reboot is required.
Check the current LRO value.
# esxcfg-advcfg -g /Net/TcpipDefLROEnabled