Microsoft® SQL Server High Availability

Windows 2003 Options for Quorum Disks and Fail-over

Starting with Windows 2003, a more durable approach of managing the quorum disks with clustering was created called majority note set. It all but eliminates the single-point-of-failure weakness in the traditional quorum disk configuration that exists with Windows 2000 servers. However, even this new approach won't always be the best option for many clustered scenarios.

The notion of “quorum” as a single shared disk resource means that the storage subsystem has to interact with the cluster infrastructure to provide the illusion of a single storage device with very strict semantics. Although the quorum disk itself can be made highly available via RAID or mirroring, the controller port may be a ...