How to Backup a dive in Dos

For this purpose Microsoft DOS backup command is to backup data of specific drive n their computer.
Backup syntax


BACKUP [Source:\Path\Filename] [Target:] [/s] [/m] [/a] [/d:date] [/t:time] [/f:size] [/L:LogDrive:\Path\Log]

Source:\Path\Filename	The source, path, and filename of the location of the file that you wish to backup.
Target:	The target drive for the backup file.
/s	Makes a backup of all files, directories, and subdirectories in the specified source location.
/m	Backup all files that have changed since the last backup.
/a	Adds a new backup file to existing backups instead of overwriting them.
/d:date	Backup files that have been created or modified since the date specified.
/t:time	Backup files that have been created or modified after this time.
/f:size	Create backup files in a specific size so they can be saved to an external storage such as a floppy disk drive.
/L:LogDrive:\Path\Log	Create a log of the backup and specify the location of where the log is to be saved.

Examples

backup c:\work\*.* d: /s

The above example would create a backup of all the files and subdirectories in the work directory and save the backup to the d: drive.

NOTE:

DOS Versions 3.3 through 5.0 stored backed up files in a different format than earlier versions (the new backup method requires less disk space). In these versions, the BACKUP program creates two files on the backup disk: BACKUP and CONTROL. The BACKUP file will contain all the files that were backed up and the CONTROL file will contain file storage information such as the paths and filenames of the source files.