MS DOS Command: DRVSPACE.EXE

Reference from Microsoft MS-DOS cmd help

Description

Compresses hard disk drives or floppy disks, and configures drives that were compressed by using DriveSpace.

Syntax

When you issue the DRVSPACE command by itself, the DriveSpace program starts. This program provides an easy-to-use, menu-oriented user interface for setting up and working with compressed drives. For more information, see "Freeing Disk Space by Using DriveSpace" in the Microsoft MS-DOS User's Guide or Microsoft MS-DOS User's Guide Addendum. For tips on using DriveSpace, see DriveSpace Tips.

If you add switches or parameters to the DRVSPACE command, MS-DOS carries out the requested task without starting the DriveSpace program. The command syntax differs from task to task. You can use the DRVSPACE command to perform the following tasks:

• Compress a hard disk drive or floppy disk. For more information, see DRVSPACE /COMPRESS.
• Create a new compressed drive in the free space on an existing drive. For more information, see DRVSPACE /CREATE.
• Defragment a compressed drive. For more information, see DRVSPACE /DEFRAGMENT.
• Delete a compressed drive. For more information, see DRVSPACE /DELETE.
• Format a compressed drive. For more information, see DRVSPACE /FORMAT.
• Display information about a compressed drive. For more information, see DRVSPACE /INFO.
• Display a list of the drives on your computer. The list includes compressed and uncompressed hard disk drives, floppy disk drives, and other removable-media drives. It does not include network drives. For more information, see DRVSPACE /LIST.
• Mount a compressed volume file (CVF). When DriveSpace mounts a CVF, it assigns it a drive letter; you can then use the files that CVF contains. For more information, see DRVSPACE /MOUNT.
• Change the estimated compression ratio of a compressed drive. For more information, see DRVSPACE /RATIO.
• Change the size of a compressed drive. For more information, see DRVSPACE /SIZE.
• Uncompress a compressed drive. For more information, see DRVSPACE /UNCOMPRESS.
• Unmount a compressed drive. For more information, see DRVSPACE /UNMOUNT.
• Change the settings in your DRVSPACE.INI file. For more information, see DRVSPACE.INI.

Remarks

Fixing problems with drives compressed using DriveSpace

To repair disk problems, use the ScanDisk program, a full-featured disk analysis and repair utility. ScanDisk can check and repair both compressed and uncompressed drives. It can even check and repair unmounted DriveSpace compressed volume files. For more information, see SCANDISK.

Running the DRVSPACE command without switches or parameters

The first time you run the DRVSPACE command, it starts the DriveSpace Setup program. DriveSpace Setup compresses your hard disk drive and loads DRVSPACE.BIN into memory. DRVSPACE.BIN is the part of MS-DOS that provides access to compressed drives.

Thereafter, when you run the DRVSPACE command without specifying any switches or parameters, the DriveSpace program starts. This program lists your compressed drives and provides menu commands for working with them. You can perform all DriveSpace tasks either from within the DriveSpace program or from the MS-DOS command line.

DRVSPACE.BIN and DRVSPACE.SYS

DRVSPACE.BIN is the part of MS-DOS that provides access to your compressed drives. When you start your computer, MS-DOS loads DRVSPACE.BIN along with other operating system functions, before carrying out the commands in your CONFIG.SYS and AUTOEXEC.BAT files. DRVSPACE.BIN initially loads in conventional memory, since it loads before device drivers that provide access to upper memory. Normally, if your hard drive has been compressed using DriveSpace, DRVSPACE.BIN is loaded even if you press F5 or F8. For information about starting your computer without loading DRVSPACE.BIN, see CONFIG.SYS commands.

The DRVSPACE.SYS device driver does not provide access to compressed drives; it simply determines the final location of DRVSPACE.BIN in memory. When loaded with a DEVICE command, the DRVSPACE.SYS device driver moves DRVSPACE.BIN from the top to the bottom of conventional memory. When loaded with a DEVICEHIGH command, DRVSPACE.SYS moves DRVSPACE.BIN from conventional to upper memory, if available. Whenever possible, DRVSPACE.SYS moves a portion of DRVSPACE.BIN into the HMA.

For more information, see the topic DRVSPACE.SYS.

How DriveSpace assigns drive letters

When you install DriveSpace, it creates a new drive and assigns a drive letter to that drive. DriveSpace skips the first four available drive letters and assigns the next available drive letter to the new drive. For example, if your computer has only drives A, B, and C, DriveSpace skips letters D, E, F, and G, and assigns drive letter H to the new drive.

When assigning letters to additional drives (for example, if you compress another drive), DriveSpace works backwards from the first drive letter it assigned. In the example above, DriveSpace would next assign the letter G.

DriveSpace attempts to avoid drive-letter conflicts with drives created by FDISK, RAMDrive, networks, or other installable device drivers that assign drive letters. However, if a drive-letter conflict does occur, DriveSpace resolves the conflict by reassigning its drive letters.

Compressing a RAMDrive

To compress a RAMDrive, use the DRVSPACE /CREATE command. Although it is possible to compress a RAMDrive by using the DRVSPACE /COMPRESS command, it is not recommended. Due to the inherent volatility of a RAMDrive, DriveSpace's automatic recovery mechanisms cannot work on a RAMDrive.

If you compress your RAMDrive, make sure the DEVICE command for RAMDRIVE.SYS appears in your CONFIG.SYS file before the DEVICE=DRVSPACE.SYS command. Otherwise, the compressed RAMDrive will not be automatically mounted when your computer starts.