Using Raw Partitions
Microsoft® SQL Server™ 2000 supports the use of raw partitions for creating database files. Raw partitions are disk partitions that have not been formatted with a Microsoft 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; you specify only the drive letters of the disks on which the database files should be created.
If you are using Microsoft Windows® 2000 Server, you can create mounted drives to point to raw partitions. When you mount a local drive at an empty folder, Windows 2000 assigns a drive path to the drive rather than a drive letter. Mounted drives are not subject to the 26-drive limit imposed by drive letters; therefore, you can use an unlimited number of raw partitions. When you create a database file on a mounted drive, you must end the drive path to the file name with a trailing backslash (\), for example, E:\Sample name\. For information about creating a mounted drive, see the Windows 2000 Server documentation.
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.
- Standard 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 a Database.
- Only lettered partitions, such as E:, or mounted drives, such as E:\Sample name\ can be used. Numbered devices cannot be used.
- File-system services such as bad block replacement are not available with raw partitions.