Here is a quick walkthrough on connecting your ESXi host to an iSCSI target.
Connecting to our ESXi server with the vSphere client is go into the configuration tab then storage adapters. Now we need to enable the iSCSI software adapter and click configure.
After enabling the software adapter we need to point it at our iSCSI target. Go to the dynamic discovery tab and “click add”.
Enter the IP address of the SAN and use port 3260
Click close and you will be prompted to rescan for storage, click yes
Our iSCSI disk will now show up under the software adapter
Go to the storage section of the configuration and click “Add Storage”
Select Disk/LUN and click “Next” then select the new iSCSI target and click “Next” and Click “Next” again
Enter a datastore name and click “Next”
Click “Next” unless you want to adjust the block size
Now your new iSCSI datastore is ready to use