format a dynamic volume

Source
Dynamic disks and volumes
Dynamic disks provide features that basic disks do not, such as the ability to create volumes that span multiple disks (spanned and striped volumes), and the ability to create fault tolerant volumes (mirrored and RAID-5 volumes). All volumes on dynamic disks are known as dynamic volumes.
Create a mounted drive
Format a dynamic volume
Assign, change, or remove a drive letter
Delete a dynamic volume

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, formatuses 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 formatcommand, 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, seeDefault 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.