To create a datastore on iSCSI SAN, you can use hardware iSCSI initiators or software iSCSI initiators. Hardware iSCSI initiators are similar to Fibre Channel HBAs. In this section, we will discuss how to create VMFS datastores using software iSCSI initiators. Before you can connect your ESXi hosts to an iSCSI LUN, your storage administrators will have to create such LUN and expose it to your ESXi servers. To set up software iSCSI initiators, you have to enable software iSCSI on your hosts using the Set-VMHostStorage cmdlet. The syntax of this cmdlet is as follows:

Set-VMHostStorage -VMHostStorage <VMHostStorageInfo[]>
    -SoftwareIScsiEnabled [<Boolean>] [-WhatIf] [-Confirm]
    [<CommonParameters>]

The -VMHostStorage and -SoftwareIScsiEnable parameters are required.

Then, you can create an iSCSI HBA target. First, you have to find iSCSI HBA using the Get-VMHostHba cmdlet. This cmdlet has the following syntax:

Get-VMHostHba [[-VMHost] <VMHost[]>] [[-Device] <String[]>]
    [-Type <HbaType[]>] [-Server <VIServer[]>] [<CommonParameters>]

This cmdlet has no required parameters.

To create the iSCSI HBA target, you can use the New-IScsiHbaTarget cmdlet. The syntax for the New-IScsiHbaTarget cmdlet is as follows:

New-IScsiHbaTarget -IScsiHba <IScsiHba[]> [-Address] <String[]>
    [[-Port] <Int32>] [-Type <IScsiHbaTargetType>] [[-IScsiName]
    <String>] [-ChapType <ChapType>] [-ChapName <String>] [-ChapPassword
    <String>] [-MutualChapEnabled [<Boolean>]] [-MutualChapName
    <String>] [-MutualChapPassword <String>] [-InheritChap
    [<Boolean>]] [-InheritMutualChap [<Boolean>]] [-Server <VIServer[]>]
    [-WhatIf] [-Confirm] [<CommonParameters>]

The -IScsiHba and -Address parameters are required.

After creating the iSCSI HBA target, we have to rescan HBAs.

iSCSI HBA has to be bound to a VMkernel port group. In the script given later, we will create a dedicated switch and VMkernel port group for iSCSI. There are no cmdlets to bind an iSCSI HBA to a VMkernel port group, so we have to fallback to the vSphere API IscsiManager BindVnic() method.

After the binding, we have iSCSI LUN that we can use to create a datastore.

The following script performs all of the necessary steps. The script first defines the variables we use and then it retrieves the VMHost object of the host on which the iSCSI datastore will be created. Software iSCSI will be enabled on this host. Then, an iSCSI target will be created, and a rescan of the HBAs will be performed on the host. A new virtual switch and a VMkernel port group will be created. The VMkernel port group will be bound to the iSCSI HBA. Finally, the new iSCSI datastore will be created.

First, we will define the variables we need for later use:

$HostName = '192.168.0.133' 
$iSCSITarget = '192.168.0.157' 
$VirtualSwitchName = 'vSwitch2' 
$NicName = 'vmnic3' 
$PortGroupName = 'iSCSI Port group 1' 
$ChapType = 'Preferred' 
$ChapUser = 'Cluster01User' 
$ChapPassword = ' Cluster01Pwd' 
$DatastoreName = 'Cluster01_iSCSI01' 

Then, we will retrieve the host to add the iSCSI datastore to and store it in the variable $VMHost:

$VMHost = Get-VMHost -Name $HostName 

We need to enable software iSCSI support on the host:

$VMHost | Get-VMHostStorage | Set-VMHostStorage -SoftwareIScsiEnabled:$true 

And we have to create an iSCSI target:

$VMHostHba = $VMHost | Get-VMHostHba -Type iSCSI 
$VMHostHba | 
New-IScsiHbaTarget -Address $iSCSITarget -ChapType $ChapType -ChapName $ChapUser -ChapPassword $ChapPassword 

Next, we have to rescan all HBAs:

$VMHost | Get-VMHostStorage -RescanAllHba 

We have to create a new virtual switch and a VMkernel port group on the host:

$vSwitch = New-VirtualSwitch -VMHost $VMHost -Name $VirtualSwitchName -Nic $NicName 
$NetworkAdapter = New-VMHostNetworkAdapter -VirtualSwitch $vSwitch -PortGroup $PortGroupName 

Now we bind the VMkernel port group to the iSCSI HBA:

$IscsiManager = Get-View -Id $vmhost.ExtensionData.Configmanager.IscsiManager 
$IscsiManager.BindVnic($VMHostHba.Device, $NetworkAdapter.Name) 

Finally, we can create the iSCSI datastore:

$ScsiLun = $VMHost | 
Get-ScsiLun | 
Where-Object {$_.Model -eq 'iSCSI Disk'} 
New-Datastore -Vmfs -VMHost $VMHost -Name $DatastoreName -Path $ScsiLun.CanonicalName