The Microsoft iSCSI Solution
An iSCSI storage array consists of two components: the target and the initiator. The server that holds the storage is called the iSCSI target. Servers such as Hyper-V connect to the iSCSI target server by using an iSCSI initiator.
What you have to keep in mind is that using a so-called software iSCSI initiator leverages only a standard network adapter, the caveat being that all the processing for the iSCSI communication is performed by the server itself—your Hyper-V host, which affects processor resources, and to a lesser extent, memory resources.If this causes a serious performance problem, a hardwareiSCSI initiator, a so-called host bus adapter (HBA), should be considered. Such an HBA would then take all the overhead associated with the iSCSI connection and minimize the resource use on the Hyper-V host.
For the remote computers the iSCSI LUN is still recognized as a standard 512-byte-sector emulation drive (512e). It’s only a 4K sector drive under the hood, but it emulates a 512-byte sector drive by presenting two sector sizes to the OS.
Components used in a Microsoft iSCSI solution
The iSCSI target server in Windows Server 2012 R2
- Stand-alone with local storage and no high availability
- Clustered with shared storage that is either SAS, iSCSI, or has Fibre Channel attached
I will cover in this section Installation and configuration of a stand-alone iSCSI target on a fresh windows 2012 r2 server, and configure iSCSI initiators to connection to iSCSI target.
Installing the iSCSI Target
1- Server Manager, choose Manage –> Add Roles And Features.
2- Select“iSCSI Target Server” And “ISCSI Target Storage Provider (VDS And VSS Hardware Providers)” from the Server Roles and click Next.
3- File Server role is automatically selected, Continue installation process.
Configuring the iSCSI Target
Let’s configure iSCSI target after roles added successfully
1- Server Manager — >File And Storage Services, click iSCSI
2- CreateiSCSIVirtualDisk, define the name and specify size
3- Select new iSCSI Target and Define the Name — >Next
4- Add — > specify the iSCSI initiators (the server which can access the virtual disk)
5- Select a method to identify the initiator (IQN, DNS, IP or MAC address); I use IPaddress to identify the initiator
6- Optionally you can enable CHAP or reverse CHAP for authentication.
7- Confirm and then click Create.
8-iSCSI Target configuration is completed after the job(s) has been completed,
Configuring the Initiator
After the iSCSI target has been created and the iSCSI virtual disk(s) is assigned to the iSCSI initiators, log on to iSCSI initiator server.
Note:the initiator and target are on different machines
1- Server Manager — > Tools — >iSCSI Initiator, the first time it will asks for permission to start the service.Click yes to automaticallystart the service.
2- Click Discovery tab — >click Discover Portal.
3- Type the iSCSI target server name or IP address,
Optional: From advance tab you can setup CHAP, IPsec…etc.
4- Click Targets tab and chose the target name from discovered targets list and then click connect.
5- Check “Enable multi-path” from “Connect To Target” windows and then click O.K
Bonus: to get IQN for initiatorClick configuration tab.make connection in your mind with step 5 for “Configuring the iSCSI Target”
5-The last step is to map the iCSI disk to local server, Tools — > Computer Management — > Disk Management (select Rescan Disks from Action if you cannot see the mapped disk), initialize and use it as any local attach disk
Hope you enjoyed, in my next post I will explain how to get benefit from Data Deduplication in your data center