SAN Boot Considerations

Applies To: Windows Server 2003, Windows Server 2003 R2, Windows Server 2003 with SP1, Windows Server 2003 with SP2

If your plan requires servers attached to a SAN to boot from disks located on the SAN, you must verify with the disk vendor that the disks can be used to boot a Windows server. When a server’s system and boot volumes are stored on a SAN, the SAN vendor must ensure that the disks are accessible during system startup. Make sure that the vendor provides specific configuration information, including needed firmware revisions and setup instructions. You will also need to ensure that each server’s HBA is configured according to the disk vendor’s guidelines for booting from a SAN.

Additional requirements for successfully booting servers from a SAN are:

  • Proper fiber channel topology is used.

    The SAN should be configured in a fabric topology, or the host can be directly attached to the Fibre Channel storage device. For more information about Fibre Channel topologies, see "SAN Configurations" earlier in this chapter.

  • Multipathing and redundant SAN links are used.

    You can avoid single points of failure in your SAN design by implementing redundant paths to the critical storage on the SAN, redundant HBAs, and MPIO-compliant drivers.

    Finally, use of the new Storport port driver and appropriate miniports from your HBA vendor will allow more flexibility in configuring your SAN. With Storport miniports, it is possible to have the boot disk and cluster disks on the same Fibre Channel connection. For more information about this configuration, see the Windows Clustering: Storage Area Networks link on the Web Resources page at

  • The boot disk LUN is dedicated to a single host.

    A server that boots from the SAN must have exclusive access to the disk that it is booting from. Exclusively associating a storage device with a server can be accomplished either through zoning or LUN masking, which is configured at the SAN switch, HBA, or storage subsystem level. Storage-based LUN masking is the best choice when you cannot use switch zoning to isolate systems. For more information about LUN masking and zoning see "LUN Masking vs. Zoning" later in this chapter.

For more information about booting from SANs, see article 305547, "Support for Booting from a Storage Area Network (SAN)." To find this article, see the Microsoft Knowledge Base link on the Web Resources page at