Multipathing; Differences Between Windows Server 2008 And Windows Server 2003; Mpio Options For The Mpx200 - HP StorageWorks MPX200 User Manual

g. Select Action > Rescan Disks. Verify that the newly assigned disk is listed; if not, you may
need to reboot.
h. Format and partition the disk to prepare it for use.

Multipathing

Microsoft MPIO includes support for redundant paths to send I/O from the initiator to the target. For
Windows Server 2008, MPIO is a separate feature that must be installed separately. Microsoft iSCSI
Software Initiator 2.x includes MPIO and must be selected for installation. Setting up redundant paths
properly ensures high availability of the target disk. Ideally, the paths would use separate network
interface cards (NICs) and a separate network infrastructure (cables, switches, and MPX200 blades).
HP recommends using separate target ports.
Microsoft MPIO allows the initiator to log in to multiple sessions to the same target and aggregate
the duplicate devices into a single device exposed to Windows. Each session to the target can be
established using different NICs, network infrastructure, and target ports. If one session fails, another
session can continue processing I/O without interrupting the application. The iSCSI target must support
multiple sessions to the same target. The Microsoft iSCSI MPIO DSM supports a set of load-balance
policies that determine how I/O is allocated among sessions. With Microsoft MPIO, the load-balance
policies apply to each LUN individually.
The Microsoft iSCSI DSM 2.x assumes that all targets are active/active and can handle I/O on any
path at any time. There is no mechanism in the iSCSI protocol to determine whether a target is
active/active or active/passive; therefore, the MPX200 supports only multipath configurations with
the EVA with active/active support. For more information, see the following:
http://www.microsoft.com/WindowsServer2003/technologies/storage/mpio/default.mspx
http://www.microsoft.com/WindowsServer2003/technologies/storage/mpio/faq.mspx
http://download.microsoft.com/download/3/0/4/304083f1-11e7-44d9-92b9-2f3cdbf01048/
mpio.doc
Table 9 details the differences between Windows Server 2008 and Windows Server 2003.
Table 9 Differences between Windows Server 2008 and Windows Server 2003
iSCSI initiator
MPIO
Table 10 lists the supported MPIO options for the MPX200.
Table 10 MPIO options for the MPX200
Multipath support
HP MPIO Full Featured
DSM for EVA (preferred)
Microsoft generic DSM
66 MPX200 iSCSI configuration rules and guidelines
Windows Server 2008
Included with operating system
Must be installed separately
Windows Server 2008
Supported
Supported
Windows Server 2003
Must be installed separately
Included with iSCSI initiator
Windows Server 2003
Supported
Supported