Microsoft Windows iSCSI host attachment

You can use iSCSI Ethernet to attach a Microsoft Windows host to the system.

Before you begin host attachment procedures:

Read the information about setting up the host server.
Ensure that you are familiar with the command-line interface commands.

Setting the iSCSI qualified name for the Microsoft Windows host

The iSCSI qualified name (IQN) can be viewed or changed on the Windows host.

To view or change the iSCSI IQN, click the Configuration tab on the Windows Server operating system. The initiator name that you choose must match the iSCSI name that is given to the host object for the system.

iSCSI target discovery for Windows hosts

The supported methods for discovering iSCSI target portals are:

Send Targets
Internet storage name service (iSNS)

Discovering iSCSI targets using Send Targets

You can discover iSCSI target portals by using the Send Targets method. The Send Targets method is configured from the Discovery tab of the iSCSI Initiator control panel.

This form of discovery requires that you to type the address of one or more of your system node Ethernet ports. For each node that you want to complete discovery on, follow these steps:

Click the Add button (click Discover Portal on Windows Server 2008) that is associated with the list of target portals.
Type the IP address or DNS name of the node Ethernet port on which you want to complete discovery. Leave the IP port name at the default value of 3260. If CHAP authentication is configured for this host on the system, see Authentication for Windows hosts.
Click OK. The system node port address is added to the list of target discovery portals.

Discovering iSCSI targets on your Windows host by using iSNS

You can discover iSCSI target portals by using the internet storage name service (iSNS) method. Before you use the iSNS discovery, complete the following tasks:

Configure the clustered system to use your iSNS server.
Verify that the system nodes registered their target portals with it.

The iSNS method is configured from the Discovery tab of the iSCSI Initiator control panel.

Click the Add button that is associated with the list of iSNS servers.
Type the IP address or DNS host name of your iSNS server.

Connecting to discovered targets

After you discover the iSCSI targets, you connect to a specific portal on a target.

The system supports only one iSCSI session between an initiator and a target. Ensure that you do not attempt to connect to the same target node more than once. Open the Targets tab of the iSCSI Initiator control panel. The list of discovered targets shows an entry for each discovered node.

To connect to a specific portal on a discovered target, complete the following steps:

Select the node that you want to connect to from the list and click Log on... (click Connect on Windows Server 2008). You can select whether to restore the connection automatically at boot or to enable multipathing for the iSCSI target from the Connect to Target window.
To connect to a specific portal on the target, such as to perform load balancing between the node Ethernet ports or to configure CHAP authentication, click Advanced... to access these settings.
Click OK to change the status for the selected targets from Inactive to Connected.
Select the node to disconnect from the list and click Log Off to stop the I/Os to the iSCSI disks. Use this option to log off from the iSCSI target.

Viewing and managing the discovered disks

You can use the Windows host to view the discovered disks and bind the devices to the Microsoft iSCSI Initiator Service. The system volumes that are mapped to the iSCSI host are now visible to the Windows disk management services. The system volumes can be initialized, formatted, and mounted.

Ensure that the iSCSI devices are available before dependent applications or services are started. You can bind these devices to the Microsoft iSCSI Initiator Service from the Bound Volumes/Devices tab on the iSCSI Initiator control panel.

If the system is rebuilt or restored from backups, you must log off and log back in to any previously connected iSCSI targets that are supplied from the system.

From the Windows host, you can view information to help you differentiate each of the discovered disks. To do so, complete the following steps.

From the Windows Command Prompt, type diskpart.
Next, type list disk.
Next, select the disk for which you want to view the details. Type select disk x where x is the number of the disk that you want to view.

Type detail disk to see the type of disk and other information. The following screen shows a sample output.

DISKPART> list disk
  Disk ###  Status      Size     Free     Dyn  Gpt
  ________  __________  _______  _______  ___  ___
  Disk 0    Online       149 GB    78 GB   *      
  Disk 1    Online       149 GB    78 GB   *      
  Disk 2    Online       565 MB   565 MB          
  Disk 3    Online       337 MB   337 MB          

DISKPART> select disk 2

Disk 2 is now the selected disk.

DISKPART> detail disk

IBM      2145             SCSI Disk Device
Disk ID: 00000000
Type   : iSCSI
Bus    : 0
Target : 2
LUN ID : 0

There are no volumes.

DISKPART>

Changes to system registry to optimize the initiator

You can change the system registry to optimize the iSCSI operation.

For reliable iSCSI operation during system maintenance, you can update these values in the system registry. See Table 1. In addition, you can also update the system registry to change the delayed acknowledgment settings to address slow performance with iSCSI operations between systems. .

Table 1. System registry
Registry key	Type	Value (decimal)
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\ {4D36E97B-E325-11CE- BFC1-08002BE10318}\`bus id`\Parameters\LinkDownTime	DWORD	120
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\ {4D36E97B-E325-11CE- BFC1-08002BE10318}\`bus id`\Parameters\MaxRequestHoldTime	DWORD	120
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Disk\TimeOutValue	DWORD	60
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\ {4D36E97B-E325-11CE- BFC1-08002BE10318}\`bus id`\Parameters\ MaxPendingRequests	DWORD	2048

Note: You must restart the computer for these changes to take effect.