Using Raw Partitions

Microsoft® SQL Server™ supports the use of raw partitions for creating database files. Raw partitions are disk partitions that have not been formatted with a Windows NT® file system, such as FAT and NTFS. In some cases, using databases created on raw partitions can yield a slight performance gain over NTFS or FAT. However, for most installations the preferred method is to use files created on NTFS or FAT partitions.

When creating a database file on a raw partition, you do not specify the physical names of the files comprising the database, only the drive letters of the disks on which the database files should be created.

There are several limitations to consider when using raw partitions:

• Only one database file can be created on each raw partition. The logical partition must be configured as a single database file, because there is no file system on the raw partition.
• Normal file system operations such as copy, move, and delete cannot be used with raw partitions.
• Database files located on raw partitions cannot be backed up using the Windows NT Backup utility; however, SQL Server database or transaction log backups can still be created.
• Database files on raw partitions cannot be automatically expanded. Either initially create the database at its full size, or manually expand the database files. For more information, see Expanding the Database.
• Only lettered partitions, such as E:, can be used; numbered devices cannot be used.
• File system services such as bad block replacement are not available with raw partitions.

See Also

CREATE DATABASE