Step-by-Step to Configure iSCSI Datastore on ESXi

Products

• VMware vSphere ESXi

Issue/Introduction

The article provides the steps to configure and mount an iSCSI datastore on an ESXi host. This is required when connecting ESXi to external storage arrays via iSCSI, so that the presented LUNs can be discovered and used as datastores.

Environment

VMware ESXi 7.x
VMware ESXi 8.x

Resolution

To confgure the iSCSI Datastore to ESXi:

1. Create network for iSCSI connectivity

In vSphere Client → select host → Configure → Networking.
Create a new vSwitch (or use a Distributed vSwitch if you manage multiple hosts) dedicated to iSCSI.

2. Create VMkernel adapter(s) for iSCSI

Host → Configure → Networking → VMkernel adapters → Add VMkernel adapter.
Select the vSwitch/portgroup for iSCSI, assign a static IP from the iSCSI subnet, set the MTU.
If planning for multipathing, create one VMkernel per physical NIC (one per uplink) or multiple VMkernels on the same subnet for port binding.
To configure iSCSI port binding with multiple NICS - Configuring iSCSI port binding with multiple NICs in one vSwitch for VMware ESXi

3. Add the iSCSI software adapter (if using software iSCSI)

Host → Configure → Storage → Storage Adapters → Click Add Software Adapter → choose Add iSCSI Adapter.
Select the newly added iSCSI adapter → Network Port Binding → Add → select the iSCSI vmk interfaces (vmk1, vmk2, etc).
For more refer to - Configure the Software iSCSI Adapter with ESXi

4. Add iSCSI target portals (Discovery)

With the iSCSI adapter selected → Targets or Dynamic Discovery → Add → enter the storage target IP (portal).
Click Rescan for the adapter. The host will query the target and list available targets/LUNs.

5. Make sure storage array is configured with all credentials.

Rescan storage adapters
Storage Adapters → select the iSCSI adapter → Rescan (or Actions → Rescan All). LUNs should appear under Devices.
Create the datastore on the discovered LUN.

Note: For each ESXi host ensure to have iSCSI vmk interfaces configured, iSCSI adapter has the same discovery portals, then rescan adapters so the new datastore appears.