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Windows File Systems. CGS2564. C:DocumentsTaxesTax04.DOC. Who Cares?. Formatting a Disk. Organizes tracks and sectors Sets up data structures on first track Boot sector Root directory File allocation table (2) Performs surface scan Checks for bad sectors. Disk Data Structures.
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Windows File Systems CGS2564
C:\Documents\Taxes\Tax04.DOC Who Cares?
Formatting a Disk • Organizes tracks and sectors • Sets up data structures on first track • Boot sector • Root directory • File allocation table (2) • Performs surface scan • Checks for bad sectors
Boot Sector • Information about the disk itself
Disk Directory • A database of what is on the disk
File Allocation Table • A table of where files are located
Units on a Disk • Sector – the smallest unit of data storage • 512 bytes (½ K) • “Allocation Unit” or “Cluster” • The actual minimum space allotted to a file • One ormore sectors
FAT 16 • Inefficient storage on large disks • Size of FAT is fixed (216 entries) • As disk capacity increases cluster size increases • Maximum disk size = 2 GB
FAT 32 • More efficient storage on large disks • Increased FAT size (232 entries) • So cluster size can be decreased • Maximum disk size = 32 GB
NTFS • Uses Master File Table system (MFT) • Even more efficient use of disk space • Support for larger disk sizes • Windows File Protection feature (WFP) • Prevents alteration or deletion of critical system files • Extended file attributes • File permissions But • Not accessible by other file systems
Wasted space not used by a file Slack Space
File Attributes • Archive • Indicates if file has changed • Used by backup programs • Read-only • Protect file from being overwritten • Hidden • Hide file from view • Additional NTFS Attributes • Compress • Encrypt • Index
Filenames • Pre Windows 95 • 8 characters max • No spaces • VFAT - Windows 95/98MFT – Windows 2000 • Support for long filenames and spaces • Stores two differentfilenames for each file • For backward compatibility
Aliases • MS-DOS filenames for long filenames
Drive:\Directory\Subdirectory\Filename.ext File Path C:\My Documents\Assignments\Assign03.doc
Types of Files • User Data Files • Created by user in application
Types of Files • Program Files • Make up application itself
Types of Files • Executable files • Actually “run” the program • Extensions • .exe • .com • .bat
File Association • Or “Registered” File type • Association between • A file extension and A file type Then between • That file type and A program’s executable file
File Association Extension File Type Executable File .DOC MICROSOFT WORD DOCUMENT WINWORD.EXE .BMP BITMAP IMAGE MSPAINT.EXE .TXT TEXT DOCUMENT NOTEPAD.EXE
Types of Files • Binary files • Contain program instructions, document information, formatting codes, etc. • User data and program files • Pure text or “ASCII” files • Contain only standard text characters • User data and program files • How to tell? • View in Notepad