About Windows NT-based Disk Striping and Striping with Parity

Microsoft® Windows NT®-based disk striping and striping with parity implement RAID features in software, using any hardware compatible with the operating system. Because these are software-based solutions provided with the operating system, they offer a cost advantage.

• Disk striping writes data in stripes across a volume (created from areas of free space). For more information about volumes, see your Windows NT documentation.

  These areas are all the same size and are spread over an array of disks (up to 32 disks). Striping writes files across all disks, so data is added to all partitions in the set at the same rate.

  Windows NT-based disk striping implements RAID 0. Disk striping provides the best performance of all Windows NT Server disk-management strategies, but does not provide any fault-tolerance protection.

• Disk striping with parity is similar to disk striping. Disk striping with parity adds a parity-information stripe to each disk partition in the volume. This provides fault-tolerance protection equivalent to that of disk mirroring, but requires much less space for the redundant data. Windows NT-based disk striping with parity implements RAID 5.

When a member of a stripe set with parity fails in a severe manner (for example, from a loss of power or a complete head crash), you can regenerate the data for that member of the stripe set from the remaining members.

Stripe sets with parity are a good solution for data redundancy in a computing environment in which most activity consists of reading data. Disk stripe sets with parity also improve write performance, but not as much as striping alone. Creating a disk stripe set with parity requires at least three physical disks on the server.

Disk striping is available on both Windows NT Server and Windows NT Workstation. However, disk striping with parity is supported only for Windows NT Server. On a dual-boot computer, stripe sets, including those with parity, are not accessible when running the Microsoft MS-DOS® operating system.

Disk striping with parity is recommended over mirroring for applications that require redundancy and are read-oriented, although disk striping with parity requires more system memory.

Disk striping and disk striping with parity are set up and managed using the Windows NT Disk Administrator application, which can be started from the Administrative Tools program group.

For more information about setting up disk striping or disk striping with parity, see your Windows NT Server documentation.