Contents
Microsoft iSCSI Software Target Getting Started Guide
iSCSI Overview
iSCSI Network Components
Microsoft iSCSI Software Target Components
In this section
Configuring Windows Firewall for iSCSI Software Target
Installing the Microsoft iSCSI Software Target
Install the Microsoft iSCSI Software Target
Installing the Microsoft iSCSI Software Target Hardware Providers
Install the VSS and VDS Hardware Providers
Virtual Disks and Snapshots
Snapshots
Hardware Providers
Command Line Utilities for Hardware Providers
VDS Hardware Provider Related Command Line Tools
VSS Hardware Provider Related Command Line Tools
Cluster Support (Enterprise Edition Only)
Supported Failover Cluster Configurations
Cluster Checklist
Legal and Copyright Information
Microsoft iSCSI Software Target Getting Started Guide
With the Microsoft iSCSI Software Target in Windows Storage Server 2008, you can create and manage iSCSI targets, create and manage virtual disks for storage, and implement backup and recovery support by using snapshots.
Note
The Microsoft iSCSI Software Target is an optional package for Windows Storage Server 2008. If it is not installed or provided together with your storage appliance, contact your storage appliance manufacturer for information about acquiring the Microsoft iSCSI Software Target.
iSCSI Overview
Several protocols, such as ATA (SATA) and SCSI (SAS), are available for enabling a disk controller to communicate with disk drives. These protocols are predefined standards that determine how commands, such as read and write requests, are packaged and sent between the controller and disk drive. The iSCSI protocol extends the SCSI standards by encapsulating SCSI commands in TCP/IP packets. These commands are sent over a TCP/IP network, which enables servers to access storage on a storage area network (SAN). This facilitates implementation and centralized management of consolidated storage, including centralized backup and remote system recovery.
iSCSI Network Components
In an iSCSI network, there are three components:
iSCSI target
The iSCSI target provides storage, similar to the disk drives of locally attached storage, but accessed over a network instead of locally. This functionality is provided in Windows Storage Server 2008 by the Microsoft iSCSI Software Target.
iSCSI initiator
The iSCSI initiator is sometimes referred to as the client. The iSCSI target provides the storage to the iSCSI initiator, which acts as a disk controller for the disks that are hosted by the target. All versions of Windows Server 2008, including Windows Storage Server 2008, include the Microsoft iSCSI Initiator to enable them to connect as a client to an iSCSI target.
Storage fabric
This is an Internet Protocol (IP)-based network that connects the iSCSI target to the iSCSI initiator. The storage fabric is typically a gigabit local area network (LAN).
Microsoft iSCSI Software Target Components
The Microsoft iSCSI Software Target package comprises three components:
Microsoft iSCSI Software Target – This component lets you create and manage virtual disks, create and manage iSCSI targets, and provide backup and recovery of iSCSI targets through snapshots.
Volume Shadow Copy Service (VSS) Hardware Provider – The VSS Hardware Provider is installed on the initiator computer and works with the VSS service to provide application consistent snapshots of iSCSI virtual disks on the computer that runs the Microsoft iSCSI Software Target.
Virtual Disk Service (VDS) Hardware Provider – The VDS Hardware Provider is installed on an initiator computer and lets VDS-aware applications manage virtual disks on a storage appliance running the Microsoft iSCSI Software Target.
Note
The iSCSI Initiator cannot connect to a Microsoft iSCSI Software Target that runs on the same computer.
In this section
Configuring Windows Firewall for iSCSI Software Target
Installing the Microsoft iSCSI Software Target
Installing the Microsoft iSCSI Software Target Hardware Providers
Virtual Disks and Snapshots
Cluster Support (Enterprise Edition Only)
Configuring Windows Firewall for iSCSI Software Target
Before you install the Microsoft iSCSI Software Target, you must configure the Windows Firewall to allow the necessary network traffic to pass. The following table lists the required ports.
Port or application / DescriptionTCP 3260 / Microsoft iSCSI Software Target Service. This port provides the primary access to the Microsoft iSCSI Software target.
TCP 135 / Remote Procedure Call (RPC), this port is required for Component Object Model (COM) communication.
UDP 138 / NetBIOS Datagram Service, this exception should already exist for File and Print Service role, but may need to be added manually if not present.
%windir%\System32\Wintarget.exe / Microsoft iSCSI Software Target Service
%windir%\System32\WTStatusProxy.exe / Microsoft iSCSI Software Target status proxy
Note
You may receive remote procedure call (RPC) errors when trying to remotely manage a Microsoft iSCSI Software Target if you do not configure the Windows Firewall exception for WTStatusProxy.exe.
The following table contains the Windows Firewall exceptions that should be made on the iSCSI initiator computer.
Application exception / Description%windir%\System32\Wtvds.exe / The Microsoft iSCSI Software Target VDS Hardware Provider
To add an inbound filter rule for a program
1.Open Windows Firewall with Advanced Security. In Server Manager, expand Configuration, expand Windows Firewall with Advanced Security, and then click Inbound Rules.2.In the Actions pane, click New Rule.
3.Under What type of rule would you like to create, click Program, and then click Next.
4.Click Browse, browse to the %windir%\System32 folder, and then click Wintarget.exe. Click Open and then click Next.
5.Click Allow the connection, and then click Next.
6.Select the network locations that should be bound to this rule (the default is Domain, Private, and Public). Click Next.
7.Under Name, type a descriptive name for the rule. For example, type Microsoft iSCSI Software Target Service for the program rule for Wintarget.exe. Click Finish.
To add an inbound filter rule for a port
1.Open Windows Firewall with Advanced Security. In Server Manager, expand Configuration, expand Windows Firewall with Advanced Security, and then click Inbound Rules.2.In the Actions pane, click New Rule.
3.Under What type of rule would you like to create, click Port, and then click Next.
4.Select the protocol for this rule, either TCP or UDP. Under Does this rule apply to all local ports or specific local ports, click Specific local ports and type in the appropriate port number.
5.Click Allow the connection, and then click Next.
6.Select the network locations that should be bound to this rule (the default is Domain, Private, and Public). Click Next.
7.Under Name, type a descriptive name for the rule. For example, type Remote Procedure Call for the RPC communication on TCP port 135. Click Finish.
Installing the Microsoft iSCSI Software Target
The Microsoft iSCSI Software Target version 3.2 is available as an optional package for Windows Storage Server 2008. You may obtain the Microsoft iSCSI Software Target package from the original equipment manufacturer (OEM) of your storage appliance.
Install the Microsoft iSCSI Software Target
The Microsoft iSCSI Software Target is distributed as a Windows Installer file, iscsitarget.msi. To install the Microsoft iSCSI Software Target files interactively, double click the .msi files. You can use the following command lines to perform the installation.
Install the Microsoft iSCSI Software Target:
msiexec /i iscsitarget.msi <options> ALLUSERS=1 [PROPERTY=PropertyValue]
Uninstall the Microsoft iSCSI Software Target:
msiexec /x iscsitarget.msi <options>
Options
Option / Description/quiet / Quiet mode, no user interface is displayed during installation.
/passive / Unattended mode, only a progress bar is displayed.
/q[n|b|r|f] / Sets user interface level:
n – No UI
b – Basic UI
r – Reduced UI
f – Full UI (default)
/L*v <logfile> / Logs all actions to the specified log file.
Properties
Property / DescriptionTARGETDIR / Specifies the root destination directory.
Installing the Microsoft iSCSI Software Target Hardware Providers
The Microsoft iSCSI Software Target version 3.2 is available as an optional package for Windows Storage Server 2008. The VDS and VSS Hardware Providers are supplied with the Microsoft iSCSI Software Target 3.2 package, and are installed on initiator computers that will connect to a storage appliance running the Microsoft iSCSI Software Target. You may obtain the Microsoft iSCSI Software Target package from the original equipment manufacturer (OEM) of your storage appliance.
Install the VSS and VDS Hardware Providers
The VDS and VSS Hardware Providers are installed through the iscsitargetClient.msi file. To install the Microsoft iSCSI Software Target files interactively, double click the .msi files. You can use the following commands to perform the installation.
Install the Microsoft iSCSI Software Target:
msiexec /i iscsitarget.msi <options> ALLUSERS=1 [PROPERTY=PropertyValue]
Uninstall the Microsoft iSCSI Software Target:
msiexec /x iscsitarget.msi <options>
Options
Option / Description/quiet / Quiet mode, no user interface is displayed during installation.
/passive / Unattended mode, only a progress bar is displayed.
/q[n|b|r|f] / Sets user interface level:
n – No UI
b – Basic UI
r – Reduced UI
f – Full UI (default)
/L*v <logfile> / Logs all actions to the specified log file.
Properties
Property / DescriptionADDLOCAL / Specifies which features to install. Available features include:
ALL - Install all features (default)
VSSProvFeature - Install the VSS Hardware Provider
VDSProvFeature – Install the VDS Hardware Provider
TARGETDIR / Specifies the root destination directory.
SERVICEUSERNAME / The VSS/VDS service account user name.
SERVICEPASSWORD / The VSS/VDS service account password.
Virtual Disks and Snapshots
The disks you create by using iSCSI Software Target are iSCSI virtual disks, which are files in the fixed virtual hard disk (VHD) format. These virtual disks offer flexible and effective storage. They can be extended to provide extra capacity on demand, enable efficient storage utilization, minimize the time that is required to create disks, and minimize the down time that is typically required to install new disks.
Snapshots
To facilitate backup and recovery operations, you can schedule and create snapshots of iSCSI virtual disks. A snapshot is a point-in-time, read-only copy of an iSCSI virtual disk. Snapshots are useful for backups and for data mining. Snapshots offer the following advantages:
Snapshots can be scheduled to be created automatically.
Snapshots are space-efficient because they are differential copies.
Snapshots are useful for fast system recovery of files and volumes, in case of accidental data deletion by a user, overwritten data, or data corruption resulting from a malicious program.
Snapshots can be mounted locally or exported to facilitate backup and recovery operations.
Snapshots do not require that you close files or stop programs when you create them, so application servers can continue servicing clients without disruption.
Note
Snapshots that are created on the iSCSI target server are crash consistent. Most modern file systems can recover from this state. To create an application-consistent snapshot, the snapshot must be created from the iSCSI initiator computer by using the Microsoft iSCSI Software Target Volume Shadow Copy Service Hardware Provider and third-party backup software that works with Volume Shadow Copy Service.
Hardware Providers
To support management of iSCSI virtual disks and snapshots, you can install the appropriate hardware providers. These hardware providers, which are available on the installation CD, include:
Microsoft iSCSI Software Target Virtual Disk Service Hardware Provider.
Virtual Disk Service (VDS) is a set of application programming interfaces (APIs) that provides a single interface for managing disks. VDS provides an end-to-end solution for managing storage hardware and disks, and for creating volumes on those disks. The Microsoft iSCSI Software Target VDS Hardware Provider is required to manage virtual disks on a storage subsystem.
You install the Microsoft iSCSI Software Target VDS Hardware Provider on each iSCSI initiator computer running a storage management application (such as Storage Manager for SANs) that uses the hardware provider to manage storage, as described later in this guide.
Microsoft iSCSI Software Target Volume Shadow Copy Service Hardware Provider.
iSCSI snapshots are created using Volume Shadow Copy Service (VSS) and a storage array with a hardware provider that works with VSS. A Microsoft iSCSI Software Target VSS Hardware Provider is required to create transportable snapshots of iSCSI virtual disks and to create application consistent snapshots from iSCSI initiators.
You install this hardware provider on the iSCSI initiator server and the server that is to perform backups.
Command Line Utilities for Hardware Providers
You can perform many of the administrative tasks for the Microsoft iSCSI Software Target from the command prompt by using standard Windows Server 2008 utilities. This topic lists some of the commands that you might find useful. See the command help in Help and Support for more information.
VDS Hardware Provider Related Command Line Tools
The following commands can be used to work with disks and volumes from the command prompt:
MountVol.exe – MountVol is used to create, delete, or display volume mount points.
DiskRaid.exe – DiskRaid is used to create, delete, and optimize physical and logical raid arrays.
VSS Hardware Provider Related Command Line Tools
The following tools can be used to work with VSS from the command prompt:
VSSAdmin.exe – VSSAdmin is used to manage the Volume Shadow Copy Service, including creating, resizing, and deleting VSS allocations on volumes.
DiskShadow.exe – DiskShadow is a tool for working with VSS, similar to VSSAdmin, but also lets you work with snapshots.
Cluster Support (Enterprise Edition Only)
This release provides support for failover clustering. This cluster support provides redundancy for shared block storage or storage area networks (SANs), enhancing the availability of applications that can be scaled out across the cluster nodes.
You implement clustering by configuring highly available instances (also known as resource groups) on storage appliances that are part of a failover cluster. Each highly available instance is a collection of resources that run together on a cluster node and are failed over as a single unit. You have the option of creating new highly available instances (resource groups) or, if you have previously configured any highly available instances, you can use those resource groups. You can use the same resource group to provide high availability for both file sharing and block sharing. For more information about the use of resource groups, see the Failover Cluster Management help file.
In an iSCSI-based cluster environment, the iSCSI virtual disk must reside on a shared cluster disk, and an existing iSCSI virtual disk can only be added to an iSCSI target that belongs to the same resource group. The Microsoft iSCSI Software Target must be installed on every node in the cluster in order to provide failover support for iSCSI resources.
Supported Failover Cluster Configurations
Windows Storage Server 2008 supports failover clustering in various configurations, each supporting increasing levels of redundancy to ensure data availability. Your storage appliances running Windows Storage Server 2008 Enterprise Edition can be used in the following failover cluster configurations:
Highly available target, single path - A single initiator computer uses an iSCSI initiator to connect to a failover cluster that contains two or more Windows Storage Server 2008 storage appliances. The storage appliances are connected to external storage, such as fiber channel or iSCSI, to provide a quorum disk and cluster storage.
Highly available target, multipath - A single initiator computer uses an iSCSI initiator by using multipath input output (MPIO) to connect to a failover cluster that contains two or more Windows Storage Server 2008 storage appliances. The storage appliances are connected to external storage, such as fiber channel or iSCSI, to provide a quorum disk and cluster storage.
Highly available initiators and targets – In this configuration, the initiators are in a highly available failover cluster connected to a failover cluster that contains two or more Windows Storage Server 2008 storage appliances. The storage appliances are connected to external storage, such as fiber channel or iSCSI, to provide a quorum disk and cluster storage. There is a single network subnet connecting the initiator cluster to the storage appliance cluster.
Cluster Checklist
Creating a failover cluster with your Windows Storage Server 2008 appliance by using the Microsoft iSCSI Software Target requires a modified procedure from the typical failover cluster. When you create a failover cluster with Windows Storage Server 2008, use the following steps as a guide:
Connect to iSCSI storage – A failover cluster requires that each node have access to storage both for cluster functions and for data storage to provide as a high available resource. If using iSCSI, use the iSCSI Initiator included with Windows Storage Server 2008 to connect each node to the iSCSI storage.
Create the failover cluster – Use the Failover Cluster Management console to create a new failover cluster.
Install the Microsoft iSCSI Software Target – If your failover cluster will provide highly available block storage, you will need to install the Microsoft iSCSI Software Target. Install the Microsoft iSCSI Software Target on each node in the cluster.