Configuring our ESXi host to accept iSCSI sessions and present volumes is part of some of our daily duties, for this guide I will show you how to configure an ISCSI LUN on your VMware vSphere ESXi environment,

It is important that your iSCSI traffic is isolated from other type of traffic, for example mgmt,

Select the ESXi host you wish to configure the iSCSI LUN and go to Manage -> Networking -> Physical adapters. Make sure you have physical adapters available that will be dedicated for your iSCSI traffic, for this example, we have vmnic2 and vmnic3.

Select Virtual switches and click on the add host networking icon.

The Add Networking window will pop up, leave the option VMkernel Network Adapter selected and click Next. Will be configuring two iSCSI VMkernels one for each vmnic.

We are going to create a new standard switch for our iSCSI traffic.

Click on the Add adapters icon and add the adapters that will be used (vmnic2 & vmni3).

Change the Network label of the first VMkernel that will be configured, example: iSCSI-01. Click next to continue.

Set an IP for this newly created VMkernel.

Here is the summary of what is going to happen. click on Finish.

Our vSwitch has been successfully created, let’s the second VMkernel and configure our vSwitch and VMkernel with the best practices, MTU, failover order and stuff, click on Add host networking once again.

Leave VMkernel Network Adapter option selected and click on next,

Select your iSCSI vSwitch in our case: vSwitch1,

Assign your VMkernel name: iSCSI-02,

Give it an IP Address of the same subnet of your iSCSI storage.

Now we have our both iSCSI Kernel and vSwitch almost configured

Select your iSCSI switch and click on Edit Settings. A new window will pop up, change the MTU (Bytes): from 1500 to 9000.

Now we are going to repeat this procedure per VMkernel, Edit Settings -> NIC Settings, change the MTU (Bytes): from 1500 to 9000.

Lastly, we are going to assign one vmnic to each vmkernel, there are currently working each vmkernel with both vmnic, select each Network label and click on edit settings, override the failover order, for iSCSI-01 vmnic2 will be active and vmnic3 will set as unused, as for iSCSI-02 vmnic2 will be set as unused and vmnic3 as active.

Time to move to the storage adapter configuration, uff sounds like We have done a lot of work at this point but trust me you’ll end up by doing this in minutes with some practice.

Move from Networking to Storage Tab, click on the Add new storage adapter icon in order to add a new iSCSI storage adapter, there are some card that you can use as iSCSI adapters but for this tutorial will be using the iSCSI software solution.

Here it is, Wohooh:

We are almost finished, let’s add the VMkernels to the Network Port Binding, select the iSCSI VMkernel you want to use for the iSCSI software adapter sessions.

Add your storage target’s IP, dynamic if your storage uses a virtual IP and it will then reassign the session to its correspondent interfaces or static if you want them to access to the LUNs by a specific route.

At this point, you must have already allowed LUN access to your iSCSI software adapter name from your storage solution, if so go ahead and perform a rescan, you will be able to see the LUNs under the devices tab.

iSCSI Name: iqn.1998-01.com.vmware:<iSCSI-Name>

And they there are, it can be now used as DataStores or be mapped as Raw Device Mapping, you will make the decision.

If you want to learn more about iSCSI Best practice you can visit Edier’s post where you will find more information about it,

Hope you enjoyed this guide,