In this step-by-step instructional guide, I will show you how to configure an Azure StorSimple 1200 virtual appliance as an MPIO-capable iSCSI storage system.
Please read Deploying a StorSimple Virtual Appliance before proceeding with this article.
Why Use iSCSI?
StorSimple will often be used when demands on an existing storage system have exceeded its capabilities. For example, an application server uses an E: drive to store terabytes of data. Demand continues to grow. The business has decided that instead of continuing to invest in fast and expensive local storage for the virtual hard disks of the virtual machine, they are going to switch to using cloud storage. They need to do so without too much configuration change.
By using the iSCSI capabilities of StorSimple, the customer can:
- Configure a volume (iSCSI LUN) on-premises of the StorSimple virtual appliance.
- Connect the application server to the StorSystem volume using the guest OS’s built-in iSCSI initiator and bring the volume online as F:.
- Shut down the application in the virtual machine.
- Copy the data from E: to F:.
- Disconnect E: from the virtual machine and change the StorSimple volume from F: to E: on the application server.
- Start the application in the virtual machine. The data is in the same volume letter but it is kept in StorSimple. This is storage that is local and tiered to Azure.
Deploying the StorSimple Virtual Appliance
When you are designing the virtual machine, you probably should keep normal iSCSI concepts in mind:
- Use 2 virtual NICs just for iSCSI, as well as the default management virtual NIC. This will allow you to have 2 iSCSI connections from each application server that is using MPIO.
- Assign these iSCSI NICs to a dedicated storage network. This is either a virtual network or VLAN.
- Do this or similar for each machine that will connect to the StorSimple virtual appliance.
- Each machine that will connect to StorSimple should have MPIO enabled. This is a feature in Server Manager on Windows Server.
When you are configuring Network Settings in the local StorSimple browser interface, you will have 3 interfaces to assign IP addresses to:
- Ethernet: The management interface and the only interface capable of talking to Azure
- Ethernet 2: The first iSCSI NIC
- Ethernet 3: The second iSCSI NIC
When you are setting up the StorSimple virtual appliance in the local browser interface, do not forget to choose iSCSI as the appliance option. You do not want the default File Server in Device Settings.
Create an iSCSI Volume
Log into your application server and retrieve the IQN for iSCSI communications. In the case of Windows Server:
- Open iSCSI Initiator. Permit the service to run after every reboot.
- Open the Configuration tab.
- Copy the IQN and keep it safe.
You can create a new iSCSI Volume in two places in the StorSimple Device Manager in the Azure Portal:
- Centrally in the StorSimple Device Manager: Treating your collection of appliances as a logical unit
- In the properties of an individual virtual appliance
Go to Volumes and click +Add Volume. In my example, I have to select a virtual appliance. Then, the reset of the Add Volume blade will populate with options. Enter the following details:
- Volume name: The name of the LUN that you want to create and share via iSCSI
- The default tiered volume: Mix of local and cloud storage
- Locally pinned: Entirely local storage
- Capacity: Between 500GB and 5TB
- Connected hosts: Permit a server to connect to the volume via iSCSI
Navigate into Connected Hosts. You can select an existing server or click Add New. I will do the latter. Enter the name of the server to describe the access control record (ACR) and paste in the IQN of the application server. Click Add.
Wait for the ACR creation task to complete. Select the ACR and click Select. The Add Volume blade is now complete and you can click Create. A new iSCSI volume is brought online after a few moments.
Adding More Servers to a Volume
You can allow more servers to connect to an iSCSI volume. Make note, this should only be done when the servers are in the same cluster and are accessing the volume in a coordinated manner.
To add more ACRs, browse to the volume in StorSimple Device Manager, open the volume, and click Connected Hosts. You can add an ACR for each server. Enter the name to describe the connection and the IQN of the server in question.