Operating SystemsCh10, part 1Details of FAT32T
Operating Systems Ch10, part 1 Details of FAT32 1
TopicsinCh10: Case studyDetailsofFAT32File attributes and directory entries, file operationsDetailsofExt2/3/4Detailed layout, detailed inode structure (file attributes), FS operations...2
Topics in Ch10 • Case study 2 File attributes and directory entries, file operations Details of FAT32 Detailed layout, detailed inode structure (file attributes), FS operations. Details of Ext2/3/4
DetailsofFAT32IntroductionDirectory and File Attributes File Operations-Readfiles-Writefiles-Deletefiles-RecoverdeletedfilesMicrosoftExtensibleFirmwareInitiativeFAT32FileSystemSpecification (FAT:GeneralOverviewofOn-DiskFormat),Version1.03,December6,2000,hardwarewhitepapers@MicrosoftCorporation.3
Details of FAT32 • Introduction • Directory and File Attributes • File Operations – Read files – Write files – Delete files – Recover deleted files 3 Microsoft Extensible Firmware Initiative FAT32 File System Specification (FAT: General Overview of On-Disk Format), Version 1.03, December 6, 2000, hardware white papers @ Microsoft Corporation
Recall on FATallocation· The layoutAblockisnamedaclusterFAT12FAT16FAT32FileSystemClusteraddr length12bits16bits32bits(28?)NumberofFilenameFirst4K64K256MBlock#clustersrock.mp3119game.exe7ubuntu.iso252627282930671819Block#802900262002730NextBlock#2EREEFileRootAllocationDirectoryTable(FAT)个←1+11121304
Recall on FAT allocation • The layout 4 A block is named a cluster. File System FAT12 FAT16 FAT32 Cluster addr length 12 bits 16 bits 32 bits (28?) Number of clusters 4K 64K 256M
TriviaWhenasectoris>512B.? Cluster Size:512B1KB2KB4KB8KB16KB32KB64KB128KB256KB- Try typing “help format" in the command prompt inWindows. Calculating the maximum partition size-withtheclustersize=32KB...(32 × 210) × 228 = 243 (8TB)5
Trivia • Cluster Size: – Try typing “help format” in the command prompt in Windows. • Calculating the maximum partition size – with the cluster size = 32KB. 5 512B 1KB 2KB 4KB 8KB 16KB 32KB 64KB 128KB 256KB When a sector is > 512B . 32 × 2 10 × 2 28 = 2 43 (8𝑇𝐵)