iSCSI


 

Small Computer System Interface (SCSI) is a widely used protocol for controlling hard drives. Internet SCSI (iSCSI) uses the SCSI protocol on network volumes. In the iSCSI paradigm, the controller is known as the initiator and the network volume is the target.


Because SCSI offers greater speed than network file systems such as SMB and NFS, consider creating iSCSI targets for users with unique applications. For example, a PC on the network used for editing audio or video can take advantage of the faster protocol. Using an iSCSI target as opposed to standard direct-attached storage provides a centralized pool of storage that is easier to manage.


Professional versions of Windows have iSCSI built into the operating system. Third-party software is also available for Macs. When an initiator is paired with a target, the target volume must be formatted for the operating system, similar to standard SCSI hard drives. For example, a Windows initiator can format the target as NTFS, and a Mac initiator can use HFS+.


WSS 2012 can also act as a name server for multiple iSCSI targets on the network. Targets register with the server, allowing initiators to connect to one device rather than search for multiple targets on the network. The WSS 2012 feature that manages iSCSI targets is called Internet Storage Name Service (iSNS). Your Seagate server can manage the naming for iSCSI targets created on its own pool of storage as well as other Windows and Linux servers on the network.

iSCSI Initiators

An iSCSI initiator is the server or computer that writes data to the iSCSI target. An initiator can search for and connect to a target on the network. It is also possible for a target to associate itself with an initiator.
An iSCSI initiator has an iSCSI Qualified Name (IQN) that can be useful when identifying the computer that is using the target. To find the initiator’s IQN on Windows:

  • Search for iSCSI Initiator and launch it. The IQN is displayed as an initiator name on the iSCSI Initiator Properties Window Configuration tab:
    iqn.nnnn-nn.com.microsoft:seagate-ddddd.

Or

  • Open a Windows PowerShell command window and type the cmdlet iscsisli. The IQN displays inside square brackets as a prompt.

Create an iSCSI target

  1. In Server Manager, select File and Storage Services.
  2. Select iSCSI.
    A table of existing iSCSI virtual disks appears.
  3. Select Tasks > New iSCSI Virtual Disk.
  4. Use the New iSCSI Virtual Disk wizard to create the disk and target. You can also optionally add an initiator.

 

Important: Connecting an iSCSI target to more than one computer on the network and sharing files can cause file corruption. The one exception is a network that includes an iSCSI cluster server with file-sharing management. WSS 2012 cannot act as an iSCSI cluster server.


 

Add an iSNS server

The iSNS provides discovery services for iSCSI initiators and targets on the network. Before you can start iSNS, you must add it as a feature to WSS 2012.

  1. In Server Manager, select File and Storage Services.
  2. Select Servers.
  3. In the server list, select the server on which to enable the iSNS.
  4. Select Tasks > Add Roles and Features.
  5. Use the Add Roles and Features wizard to add an iSNS.
  6. Under Installation Type, select Role-based or feature-based installation and click Next.
  7. Select the server and click Next.
  8. Under File and Storage Services > File and iSCSI Services, select Features.
  9. Select iSNS Server service and click Next to complete the installation.
  10. If prompted, restart the server.

Register an iSCSI target with an iSNS server

Make sure that iSNS has been added as a feature WSS 2012.

  1. Launch the PowerShell on the iSCSI target server.
  2. Type:
    Set-WmiInstance -Namespace root\wmi -Class WT_iSNSServer –Arguments @{ServerName="Your_iSNS_ServerName"}
    Where Your_iSNS_ServerName is the iSNS server name.

 

Important: Third-party or compatible NAS devices can have specific settings to join an iSCSI target to an iSNS server. Seagate NAS OS devices have a setting to join iSCSI targets to an iSNS server.


 

Register an iSCSI initiator with an iSNS server (Windows only)

Make sure that iSNS has been added as a feature WSS 2012.

  1. On your Windows computer, search for and launch iSCSI initiator.
  2. On the Discovery tab, under iSNS servers, click Add Server.
  3. Specify the IP address or DNS name of the iSNS server and click OK.
  4. Click Refresh.
    The iSNS server is added to the list of iSNS servers.
  5. Click OK to close the iSCSI Initiator Properties window.