Disks and File Systems: The Basics

The new 32-bit, protected-mode file system support in Windows 95 allows optimal access to hard disks, CD-ROM drives, and network resources. The new file system support means faster, better performance for all file I/O operations than what was available under earlier version of MS-DOS or Windows.

Because of enhancements to the file systems, there is no longer an eight-character limit on filenames that was imposed by the FAT file system under MS-DOS. You can use long filenames and directory names in Windows 95 and in any applications that support long filenames.

The enhanced FAT file system in Windows 95 also permits exclusive access to a disk device for file system utilities. File system utilities, such as ScanDisk, require exclusive access to the file system to ensure data integrity in a multitasking environment. Otherwise, if a file on the disk were to be saved while the utility was writing information to the disk at the same time, data corruption could occur.

Exclusive disk access means you can now run disk management and optimization utilities without quitting Windows. You can even complete tasks such as disk defragmentation without stopping work in other applications. The exclusive access support is used by the disk utilities provided with Windows 95 and can be used in Windows-based disk management utilities from any vendors that take advantage of the related API in their utilities.

The disk utilities provided with Windows 95 include the following.

Fdisk and Format.

These utilities, which you can use to partition and format disks, behave exactly as their counterparts in MS-DOS versions 6.x. You can use a graphical form of Format in Windows Explorer.

Disk Defragmenter.

This utility (also called a disk optimizer) is used to defragment information on a disk. Using Disk Defragmenter regularly helps to minimize the area on the disk in which Windows 95 needs to look to load information.

DriveSpace (DBLSPACE).

The built-in support for DriveSpace disk compression is completely compatible with DoubleSpace and DriveSpace disk compression provided with MS-DOS 6.x. Compression is performed by using a 32-bit virtual device driver that delivers improved performance over previously available real-mode compression drivers, and frees conventional memory for use by MS-DOS–based applications. Existing users of DoubleSpace and DriveSpace do not need to change the compressed volume file (.CVF) that they are using currently, and they do not need to take any special actions when installing Windows 95.

ScanDisk.

This graphical disk analysis and repair tool runs under Windows 95 to help users check the integrity of disks and to remedy the problems it detects. Users can choose to scan the computer's files and folders or the disk surface for errors.