230 IBM System Storage N series Hardware GuideThe iSCSI software initiator provides excellent performance. In fact, an iSCSI softwareinitiator provides better performance than an iSCSI HBA in most configurations. The iSCSIinitiator software for Windows is available from Microsoft for no charge. In some cases, youcan even SAN boot a host with an iSCSI software initiator and a supported NIC.iSCSI HBAs are best used for SAN booting. An iSCSI HBA implements SAN booting as doesa Fibre Channel HBA. When you are booting from an iSCSI HBA, use an iSCSI softwareinitiator to access your data LUNs.Select the appropriate iSCSI software initiator for your host configuration. Table 17-1 listsoperating systems and their iSCSI software initiator options.Table 17-1 iSCSI initiator instructionsInstalling multipath I/O softwareYou must have multipathing set up if your Windows host has more than one path to thestorage system.The MPIO software presents a single disk to the operating system for all paths, and adevice-specific module (DSM) manages path failover. Without MPIO software, the operatingsystem might see each path as a separate disk, which can lead to data corruption.On a Windows system, there are two main components to any MPIO solution: a DSM and theWindows MPIO components.Operating System InstructionsWindows Server2003Download and install the iSCSI software initiator.Windows Server2008The iSCSI initiator is built into the operating system. The iSCSI Initiator Properties information isavailable from Administrative Tools.Windows Server2008 R2The iSCSI initiator is built into the operating system. The iSCSI Initiator Properties information isavailable from Administrative Tools.Windows XP guestsystems onHyper-VFor guest systems on Hyper-V virtual machines that access storage directly (not as a virtual harddisk mapped to the parent system), download and install the iSCSI software initiator. You cannotselect the Microsoft MPIO Multipathing Support for iSCSI option. Microsoft does not supportMPIO with Windows XP. A Windows XP iSCSI connection to IBM N series storage is supportedonly on Hyper-V virtual machines.Windows Vistaguest systems onHyper-VFor guest systems on Hyper-V virtual machines that access storage directly (not as a virtual harddisk mapped to the parent system), the iSCSI initiator is built into the operating system. The iSCSIInitiator Properties dialog is available from Administrative Tools. A Windows Vista iSCSIconnection to IBM N series storage is supported only on Hyper-V virtual machines.SUSE LinuxEnterprise Serverguest systems onHyper-VFor guest systems on Hyper-V virtual machines that access storage directly (not as a virtual harddisk mapped to the parent system), use an iSCSI initiator solution. This solution must be on aHyper-V guest that is supported for stand-alone hardware. A supported version of Linux HostUtilities is required.Linux guestsystems on VirtualServer 2005For guest systems on Virtual Server 2005 virtual machines that access storage directly (not as avirtual hard disk mapped to the parent system), use an iSCSI initiator solution. This solution mustbe on a Virtual Server 2005 guest that is supported for stand-alone hardware. A supportedversion of Linux Host Utilities is required.
