Notes

Outline

Creating a New Folder in Windows 9x

Deleting a Folder in Windows 9x

Slide 3

Optimizing a Hard Drive Fragmentation Cross-linked and lost clusters Disk compression Disk caching

Fragmentation Distribution of data files in noncontiguous clusters; increases data access time Routine maintenance:  defragment the hard drive DOS DOS 6+ DEFRAG or a utility software package Windows 98 Defragmenter utility

Windows 98 Defragmenter Utility

Disk Defragmenter Results

Cross-linked and Lost Clusters Cross-linked More than one file points to them Lost No file in the FAT points to them To repair:  use ScanDisk utility in either DOS or Windows 9x

Cross-linked and Lost Clusters

SCANDISK Command for DOS

ScanDisk

ScanDisk

Disk Compression Compresses data on a hard drive to allow more data to be written to the drive Works by Storing data on the hard drive in one big file and managing the writing of data and programs to that file Rewriting data in files in a mathematically coded format that uses less space

Disk Compression in DOS and Windows 3.x Uses a device driver loaded in the CONFIG.SYS file PKZIP

Parts of a Compressed Drive Host drive Compressed volume file (CVF)

Disk Compression in Windows 9x Uses DriveSpace to: Assign different drive letter to hard drive, (e.g., H) Compress entire contents of hard drive into a single file on drive H Set up the drive so that Windows 9x and other applications view this compressed file as drive C Configure Windows 9x so that each time it boots, DriveSpace driver will load and manage the compressed drive

Disk Compression in Windows 9x

Disk Compression in Windows 9x

Disk Compression in Windows 9x

Disk Compression in Windows 9x

Disk Compression in Windows 9x

Disk Compression in Windows 9x

Disk Caching A method whereby recently retrieved data and adjacent data are read into memory in advance, anticipating the next CPU request

Disk Caching

Hardware Cache or Software Cache Hardware cache A disk cache that is contained in RAM chips built right on the disk controller Software cache Cache controlled by software whereby the cache is stored in RAM

Hardware Cache or Software Cache Hardware cache disadvantages Slower than a software cache A permanent part of the hard drive controller Software cache Disadvantage Uses RAM for both the cache program itself and the data being cached; RAM is used that might otherwise be used for applications software and its data Advantage Faster than hardware cache

Disk Cache in DOS and Windows 3.x SMARTDrive A 16-bit real mode software cache utility that comes with DOS and Windows 3.x Can be executed as a TSR from the AUTOEXEC.BAT file Other packages Norton Cache Mace Cache Super PC-Kwik Cache

VCACHE in Windows 9x A built-in Windows 9x 32-bit software cache that doesn’t take up conventional memory space or upper memory space, as SmartDrive does

DOS Buffers An area in memory where data waiting to be read or written is temporarily stored

Using DOS under Windows 9x to Manage a Hard Drive CAUTION:  Using some DOS commands on a hard drive that uses Windows 9x as the OS may cause damage to a hard drive’s file structure

DOS Commands to Avoid with Windows 9x Don’t use disk utility software that does not know about VFAT, long filenames or FAT32 Don’t use FDISK, FORMAT C:, SYS C:, or CHKDSK while in a DOS session Don’t optimize or defragment the hard drive using software that does not know about long filenames

DOS Commands to Avoid with Windows 9x Don’t run hard drive cache programs unless written especially for Windows 95 or Windows 98 Don’t use older DOS backup programs (BACKUP, MSBACKUP)

Removable Drives High-capacity drives, such as Zip or Jaz drives, that have disks that can be removed like floppy disks

Chapter Summary Hard drive similarities to floppy drives Has a file allocation table (FAT) and a root directory Stores data on tracks that are divided into sectors, each of which contains 512 bytes Methods of organizing and formatting data Managing a healthy, previously installed hard drive Hard drive technologies