Tips on tuning VMware ESXi for EqualLogic SANs.

  1. Install Dell MEM
    1. Download from here:
    2. Important: Unzip the package and inside the package is another zip file.  That’s the file that should be uploaded to a datastore so that it’s accessible from the host.
    3. SSH into the host and run the following (substituting your version of MEM).  I found that sometimes I needed to use the actual path name instead of the datastore friendly name in order to work:
      esxcli software vib install –depot /vmfs/volumes/vmfsvol/dell/
      (There are two dashes in front of “depot”, WordPress may format it differently.)
    4. Before rebooting complete next section.
  2. Disable large receive offload (LRO)
    1. Fist check to see if it’s enabled: esxcfg-advcfg -g /Net/TcpipDefLROEnabled
    2. If enabled disable it: esxcfg-advcfg -s 0 /Net/TcpipDefLROEnabled
    3. Reboot
  3. Tune the virtual and physical networks
    1. Change the MTU to 9000 on the virtual iSCSI switch and virtual iSCSI NICs
    2. Change the MTU on the physical iSCSI switches.  On some Cisco switches this is a global config and others this is an interface config (and possibly both)
  4. Tune the iSCSI Initiator
    1. Go to the host -> Configuration tab -> Storage Adapters -> iSCSI Initiator -> Properties -> Advanced
      1. Change LoginTimeout from 5 to 60
      2. DelayedAck should be unchecked  (Update: for the delayed ACK setting to take effect, the static and dynamic iSCSI discoveries need to be deleted and the server needs to be rebooted.)
  5. Tune the VM
    1. Put all VMDKs on a separate virtual SCSI/SAS controller (i.e. node 1:0, 2:0, 3:0, NOT 1:0, 1:1, 1:2)
    2. Format the partitions with 64K cluster (allocation unit) size
    3. For VMs that need high IOPs, convert your virtual storage controller from LSI to Paravirtual.  This is easiest by first changing the controller for the data drive and rebooting (so that drivers can be installed), then convert the boot drive.
  6. Test your VM speed with ATTO Disk Benchmark