VMware storage entails more than simply mapping a logical unit number (LUN) to a physical server. SAN (Storage Area Network) storage, however, provides a shared, highly available and resilient storage platform that can scale to a multi-server deployment. In mostly use cases VMware vSphere use SAN, or block-based devices, which includes the iSCSI, Fibre Channel and Fibre Channel over Ethernet (FCoE) protocols.
An important architectural feature of vSphere block storage is the use of the VMware File System (VMFS). In the same way a traditional server formats block devices with a file system, so vSphere uses VMFS on block LUNs to store virtual machines. The vSphere unit of storage is known as a datastore and can comprise one or more LUNs concatenated together. In many instances, vSphere deployments have a 1:1 relationship between the LUN and the datastore.
vSphere supports Fibre Channel, FCoE and iSCSI block storage protocols. Fibre Channel protocols provide a multi-path, highly resilient infrastructure, but require additional expense for dedicated storage networking equipment, such as Fibre Channel switches and host bus adapters (HBAs). By contrast, iSCSI provides a cheaper option for shared storage, as network cards are typically much cheaper than Fibre Channel HBAs and converged network adapters (CNAs).
Today we will configure iSCSI adapters in vSphere 6.5, discover LUNs and then create VMFS datastore based on those luns.
To access iSCSI targets, your host uses iSCSI initiators. The initiators transport SCSI requests and responses, encapsulated into the iSCSI protocol, between the host and the iSCSI target. ESXi hosts supports different types of initiators:
– A software iSCSI adapter is a VMware code built into the VMkernel. Using the software iSCSI adapter, your host can connect to the iSCSI storage device through standard network adapters.
– A hardware iSCSI adapter is a third-party adapter that offloads iSCSI and network processing from your host. Hardware iSCSI adapters are divided into categories:
- Dependent Hardware iSCSI Adapter
- Independent Hardware iSCSI Adapter
First if we want to use the software or dependent hardware iSCSI adapters, we have to configure the network connection, which involves creating a virtual VMkernel adapter for each physical network adapter. You then associate the VMkernel adapter with an appropriate iSCSI adapter. This process is called port binding.
Login to your vsphere web client with your credentials and go to Host & Clusters, choose a host you will configure -> Configure -> VMkernel adapters and click icon for new adding.
Choose a VMkernel Network Adapter to create and click Next.
Here you can select to create a new standard switch with vmkernel adapter or to add to an existing standard switch. I choose an existing vSwitch0 to add this new vmkernel adapter. For production environment, best practice is to create new vSwitch. Click Next to continue.
Here specify the IP for iSCSI target you will access and subnet mask. Click Next.
Note: iSCSI ports of the array target must reside in the same broadcast domain and IP subnet as the VMkernel adapters.
On Ready to complete screen, review the configurations you made and click Finish to create new VMkernel adapter. After task is complete, you can see the new vmkernel port created on vSwitch0.
Next step is to configure port binding for iSCSI. iSCSI port binding creates connections for the traffic between the software or dependent hardware iSCSI adapters and the physical network adapters.
First add new software iSCSI adapter. Go to the host -> Configure -> Storage Adapters -> click () icon to add new Software iSCSI adapter.
Click OK on the warning screen for adding new Software iSCSI adapter to the host.
After task is complete, you will see the new iSCSI adapter created. Next step is to Bind an iSCSI adapter with a VMkernel adapter. Click on new iSCSI adapter created and under Adapter Details, click the Network Port Binding tab and click the Add icon ().
Select a VMkernel adapter to bind with the iSCSI adapter, one which we created in above steps. Click OK.
Then under Adapter details of the iSCSI adapter, you configure also iSCSI Target. Click Add.
Enter the IP of the iSCSI target server and click OK.
For all changes to take effects, you must do a rescan of all adapters. Click on icon highlighted on Storage Adapters page. Click OK on Rescan Storage screen below.
After rescan is completed, under Adapters details click on Devices and Paths tab to see listed the new LUNs discovered by iSCSI target.
You have successfully add iSCSI devices to an ESXi hosts.
Next we will Create VMFS6 datastore in vSphere 6.5 from this iSCSI adapters.