Introduction to iSCSI SAN in Windows Server 2012 R2

A) Introduce

iSCSI (Internet Small Computer System Interface) is a protocol running on TCP/IP platform, allowing to connect to Storage by Network (LAN/WAN). Defined by IETF, the protocol allows SCSI commands to be transmitted over the network, making it possible to access and transmit data over long distances.

When a user or an application sends a request to access data in Storage, the system generates a number of SCSI commands corresponding to the request, then encapsulates (Encapsulate) and encrypts (Encrypt) and sends go on the network road. When the Server receives it, it will De-Encapsulate and decrypt (Decrypt) to finally receive the SCSI commands. SCSI commands will be entered into the SCSI Controller for execution and processing as required.

In the Storage system, LUN (Logical Unit Number), is a logical number used to collect drives running using SCSI, iSCSI and Fiber Channel protocols. In other words, the LUN is a place to centrally manage the drives in the Network storage system (Storage Area Network – SAN).

iSCSI drives are created from servers running operating systems such as Windows/Linux. And LUNS will assign iSCSI a logical number and call it “Target”. When a server or a device wants to connect to the iSCSI SAN system, they will use a software called iSCSI Initiator to connect to this “Target” number. And this number will manage the connection between iSCSI Target and iSCSI Initiator

From Windows Server 2008 and later, Microsoft supports the creation of iSCSI SAN storage systems and they are called “iSCSI Targets Server”. It allows the deployment of SAN storage systems based on the iSCSI protocol without investing in expensive and high-cost SAN systems like Fiber Channel. Support for small and medium businesses.

B) Benefits of ISCSI Target Server (Benefits)

• iSCSI Target Server allows connection to iSCSI SAN without using Microsoft’s iSCSI Initiator software (For example Linux platform)
• Considered as Block Storage platform, it supports applications that require running on Block Storage platform, compatible and integrated with Failover Clustering feature to increase availability for applications.
• For using Hyper-V feature, iSCSI SAN allows storage of virtual machines (Virtual Machine), and supports some High Availability features such as (Live Migration, Storage Migration, Failover Clustering).

C) ISCSI Target Server in Windows Server 2012 R2

• Virtual Disk Enhancement : VHDX is a new storage standard that allows for more storage, increases fault tolerance when something goes wrong, optimizes the stacking and storage structure, allowing for significant performance gains.
• Scalability : allows 544 connections from Initiators to Target Server, and supports up to 256 iSCSI Disks in that Target Server.

D) Instructions for configuring and creating an iSCSI SAN on Windows Server 2012 R2

Model :

• Domain Controller (172.1.1.1/24) : install iSCSI Target Server feature
• Hyper-V1 machine (172.1.1.2/24) : use iSCSI Initiator feature to connect to iSCSI Target Server
• Hyper-V2 machine (172.1.1.3/24) : use iSCSI Initiator feature to connect to iSCSI Target Server

Perform :

• On the Domain Controller machine: go to Server Manager and click “Add Roles and Features”

1. Go to File and Storage Services -> File and iSCSI Services -> iSCSI Target Server

• After the installation is complete, go to: Server Manager -> File and Storage Services -> Volume -> Click on Task -> “New iSCSI Virtual Disk”.

• Select drive F to create (because drive F in Lab has 31.2GB free)

• Name iSCSI Virtual Disk

• Here I create an iSCSI Virtual Disk with 20GB capacity and Fixed Size mechanism

• The above steps just created an iSCSI Virtual Disk, the next thing is to create an iSCSI Target (LUNs) and mount the newly created iSCSI Virtual Disk to the Target.

• Name the iSCSI Target

• This step allows to declare which servers are connected to the iSCSI Target. Click Add and add 2 addresses of 2 Hyper-V Servers.

• Confirm and create to proceed with the creation.

• At this point, it has been successfully created and an iSCSI SAN . appears

• Go to drive F and see that the system creates a VHDX file to contain iSCSI SAN

This step is the step to declare iSCSI Target for 2 Hyper-V Servers. Done on both machines

• Go to Server Manager -> Tools -> iSCSI Initiator

• The system will tell you that you have not started the “Microsoft iSCSI” service. Select Yes to start this service up.

• Declare the IP of iSCSI Target Server -> Then select “Quick Connect” to proceed with the connection.

• The next step you need to do is to boot this iSCSI SAN drive. Go to Start -> Run -> type “Diskmgmt.msc” (Performed on both Hyper-V Servers)

• Right-click and select “Online”

• Next right-click and select “Initilize Disk”

• New Volume for Virtual Disk

• Choose GPT (GUID Partition Table): is an upgraded version from MBR, allowing to support more capacity than MBR mechanism

• Then format (note: you can uncheck “Quick Format” to proceed with a more detailed Format)

• Now we have a shared iSCSI SAN.