If you are using Raw Device Mapped (RDM) disks in your VM's, make sure the pathing for that is changed to RR and IOPs 3 as well. (MEM would also set this connections up properly as well)
Other common tweaks are disable DelayedACK (its in the iSCSI initiator properties) and disable Large Receive Offload (LRO)
Within VMware, the following command will query the current LRO value.
# esxcfg-advcfg -g /Net/TcpipDefLROEnabled
To set the LRO value to zero (disabled):
# esxcfg-advcfg -s 0 /Net/TcpipDefLROEnabled
NOTE: a server reboot is required.
Info on changing LRO in the Guest network.
ESXI v5.0 should also have the Login Timeout changed to 60 seconds. (default is 5). However, you have to be at build 514841 or better.
See VMware KB 2007680 kb.vmware.com/.../2007680
One more common enhancement that gets missed often is creating a virtualized SCSI adapter for each VMDK (or RDM) in each VM. (Up to 4x controllers) If you look in the VM settings, each VMDK/RDM shows a "Virtual node"
It will say 0:0, for first drive, then 0:1, 0:2, etc... Shutdown the VM, change the other VMDK/RDMs from 0:1 to 1:0, then 0:2 to 2:0 and so on. This will tell ESX to create new SCSI controllers for each disk. Really helps with Exchange/SQL/Sharepoint. Things that have databases and logs or fileservers that have multiple VMDKs/RDMs
*************************************************************************************
*** Script to change EQL volumes to RR and set the IOPs to 3 in ESXi v5.0. ****
*************************************************************************************
This is a script you can run to set all EQL volumes to Round Robin and set the IOPs value to 3. (Datastores and RDMs)
#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
