Format a dynamic volume

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

To format a dynamic volume

  • Using the Windows interface

  • Using a command line

Using the Windows interface

  1. Open Computer Management (Local).

  2. In the console tree, click Computer Management (Local), click Storage, and then click Disk Management.

  3. Right-click the volume you want to format (or reformat), and then click Format.

  4. Select the options you want, and then click OK.

Notes

  • To perform this procedure on a local computer, you must be a member of the Backup Operators group or Administrators group on the local computer, or you must have been delegated the appropriate authority. To perform this procedure remotely, you must be a member of the Backup Operators group or Administrators group on the remote computer. If the computer is joined to a domain, members of the Domain Admins group might be able to perform this procedure. As a security best practice, consider using Run as to perform this procedure. For more information, see Default local groups, Default groups, and Using Run as.

  • To open Computer Management, click Start, click Control Panel, double-click Administrative Tools, and then double-click Computer Management.

  • You cannot format the system or boot volume.

  • Before you enable shadow copies on a volume, we recommend that you select a cluster size of 16 KB or larger. If you do not, the number of changes caused by defragmenting the volume might cause previous versions of files to be deleted.

  • File compression is supported only on NTFS volumes with cluster sizes 4 KB and smaller.

  • If you select the Perform a quick format check box, the files are removed from the disk but the disk is not scanned for bad sectors. Use this option only if this disk has been previously formatted and you are sure the disk is not damaged.

  • Only the NTFS file system is available for dynamic volumes in Disk Management. However, you can format dynamic volumes with either the FAT or FAT32 file systems using the format command.

Using a command line

  1. Open Command prompt.

  2. Type:

    formatvolume[/fs:filesystem] [/v:label] [/q] [/a:unitsize] [/c]

Value Description

Volume

Specifies the mount point, volume name, or drive letter of the drive you want to format. If you do not specify any of the following command-line options, format uses the volume type to determine the default format for the disk.

/fs: filesystem

Specifies the file system to use FAT, FAT32, or NTFS. Floppy disks can use only the FAT file system.

/v: label

Specifies the volume label. If you omit the /v command-line option or use it without specifying a volume label, format prompts you for the volume label after the formatting is completed. Use the syntax /v: to prevent the prompt for a volume label. If you format more than one disk by using one format command, all of the disks will be given the same volume label.

/q

Performs a quick format. Deletes the file table and the root directory of a previously formatted volume but does not perform a sector by sector scan for bad areas. You should use the /q command-line option to format only previously formatted volumes that you know are in good condition.

/a: unitsize

Specifies the cluster size, also known as allocation unit size, to use on FAT, FAT32, or NTFS volumes. Use one of the following values for unitsize. If unitsize is not specified, it will be chosen based on volume size.

512 - Creates 512 bytes per cluster.

1024 - Creates 1024 bytes per cluster.

2048 - Creates 2048 bytes per cluster.

4096 - Creates 4096 bytes per cluster.

8192 - Creates 8192 bytes per cluster.

16K - Creates 16 kilobytes per cluster.

32K - Creates 32 kilobytes per cluster.

64K - Creates 64 kilobytes per cluster.

/c

NTFS only. Files created on the new volume will be compressed by default.

Notes

  • To perform this procedure on a local computer, you must be a member of the Backup Operators group, Administrators group, or you must have been delegated the appropriate authority. If the computer is joined to a domain, members of the Domain Admins group might be able to perform this procedure. As a security best practice, consider using Run as to perform this procedure. For more information, see Default local groups, Default groups, and Using Run as.

  • To open a command prompt, click Start, point to All programs, point to Accessories, and then click Command prompt.

  • You cannot format the system or boot volume.

  • Quick format removes files from the disk but does not scan the disk for bad sectors. Use this option only if this disk has been previously formatted and you are sure the disk is not damaged.

  • Before you enable shadow copies on a volume, we recommend that you select a cluster size of 16 KB or larger. If you do not, the number of changes caused by defragmenting the volume might cause previous versions of files to be deleted.

  • File compression is supported only on NTFS volumes with cluster sizes 4 KB and smaller.

  • For Windows NT 4.0, Windows 2000, Windows XP Professional, and Windows Server 2003 operating systems, the cluster size of FAT16 volumes from 2 GB through 4 GB is 64 KB, which can create compatibility issues with some applications. For example, setup programs do not compute free space properly on a volume with 64 KB clusters and cannot run because of a perceived lack of free space. For this reason, either FAT32 or NTFS must be used on volumes larger than 2 GB. Format displays a warning and asks for a confirmation before formatting a volume that has 64 KB clusters using FAT16.

  • For more information about format, see Related Topics.

Information about functional differences

  • Your server might function differently based on the version and edition of the operating system that is installed, your account permissions, and your menu settings. For more information, see Viewing Help on the Web.

See Also

Concepts

Assign, change, or remove a drive letter
Create a mounted drive
Dynamic disks and volumes
Working with MMC console files
Format
DiskPart