Create LUN's where it defaults to most recently used is an extra workload that is not needed.

Create LUN's where it defaults to most recently used is an extra workload that is not needed.

System administrators can create a pathing policy for iSCSI SAN's regardless of vendor. First, add the iSCSI target into ESXI connecting to the target and SSH to your host. In the SSH console run "esxcli storage nmp device list" which will provide an output like:

naa.6000d3100d216a000000000000000005
   Display Name: COMPELNT iSCSI Disk (naa.6000d3100d216a000000000000000005)
   Has Settable Display Name: true
   Size: 102400
   Device Type: Direct-Access
   Multipath Plugin: NMP
   Devfs Path: /vmfs/devices/disks/naa.6000d3100d216a000000000000000005
   Vendor: COMPELNT
   Model: Compellent Vol

   Revision: 0704
   SCSI Level: 5
   Is Pseudo: false
   Status: on
   Is RDM Capable: true
   Is Local: false
   Is Removable: false
   Is SSD: false
   Is VVOL PE: false
   Is Offline: false
   Is Perennially Reserved: false
   Queue Full Sample Size: 0
   Queue Full Threshold: 0
   Thin Provisioning Status: yes
   Attached Filters:
   VAAI Status: supported
   Other UIDs: vml.02000300006000d3100d216a000000000000000005436f6d70656c
   Is Shared Clusterwide: true
   Is SAS: false
   Is USB: false
   Is Boot Device: false
   Device Max Queue Depth: 128
   No of outstanding IOs with competing worlds: 32
   Drive Type: unknown
   RAID Level: unknown
   Number of Physical Drives: unknown
   Protection Enabled: false
   PI Activated: false
   PI Type: 0
   PI Protection Mask: NO PROTECTION
   Supported Guard Types: NO GUARD SUPPORT
   DIX Enabled: false
   DIX Guard Type: NO GUARD SUPPORT
   Emulated DIX/DIF Enabled: false

From this you want the Vendor and Model to create your rule:

esxcli storage nmp satp rule add -s "VMW_SATP_ALUA" -V "Vendor" -M "Model" -P "VMW_PSP_RR" -O "iops=1"

For all new LUNS created they will now have round-robin iSCSI with 1 IO per path before moving to the next. We have tested multiple deployments and this provides great load balancing along with performance.

If you have many hosts and would like to powercli the change:

Connect-VIServer -Server <vCenter>
Get-VMhost | Get-EsxCli –V2 | % {$_.storage.nmp.satp.rule.add.Invoke(@{description='SAN SATP';model='Model';vendor='Vendor';satp='VMW_SATP_ALUA';psp='VMW_PSP_RR'; pspoption='iops=1'})}
-Credential (Get-Credential)