SlideShare a Scribd company logo
Linux Forensics
Examining Linux File Structures
• UNIX flavors
• Silicon Graphics, Inc. (SGI) IRIX, Santa Cruz Operation (SCO)
UnixWare, Sun Solaris, IBM AIX, and HP-UX
• Linux distributions
• Ubuntu, Debian, Red Hat, OpenSUSE, and Slackware
• Linux is only the core of the OS
• All UNIX-like OSs have a kernel
• So do all Windows OSs
Examining Linux File Structures
Examining Linux File Structures
File Structures in Ext4
• The early file system standard was Second Extended File System (Ext2)
• Third Extended File System (Ext3) replaced Ext2 in most Linux distributions
• Fourth Extended File System (Ext4) added support for partitions larger than
16 TB
• Improved management of large files and offered more flexibility
• Adoption of Ext4 was slower in some Linux distributions
• Everything is a file
• Files are objects with properties and methods
File Structures in Ext4
Consists of four components
• Boot block
• Block is a disk allocation unit of at least 512 bytes
• Contains the bootstrap code
• UNIX/Linux computer has only one boot block,
located on the main hard disk
• Superblock
• Indicates disk geometry, available space, and location
of the first inode
• Manages the file system
• Inode blocks
• First data after the superblock
• Assigned to every file allocation unit
• Data blocks
• Where directories and files are stored
• This location is linked directly to
inodes
Inodes
• Contain file and directory metadata
• Also link data stored in data blocks
• An assigned inode contains the following:
• Mode and type of file or directory
• Number of links to a file or directory
• UID and GID of the file’s or directory’s
owner
• Number of bytes in the file or directory
• File’s or directory’s last access time and last
modified timeInode’s last file status change
time
• Block address for the file data
• Indirect, double-indirect, and triple-indirect
block addresses for the file data
• Current usage status of the inode
• Number of actual blocks assigned to a file
• File generation number of version number
• Continuation inode’s link
Inodes
• First inode has 13 pointers
• Pointers 1 to 10 are direct pointers to data storage blocks
• Pointer 11 is an indirect pointer
• Links to 128 pointer inodes and each pointer links directly to 128 blocks
• Pointer 12 is a double-indirect pointer
• Pointer 13 is a triple-indirect pointer
• Bad block inode
• Keeps track of disk’s bad sectors
Hard Links and Symbolic Links
Hard link
• A pointer that allows accessing the
same file by different filenames
• Use the ln command to create a
hard link
Symbolic links
• Pointers to other files and aren’t included in
the link
• Have an inode of their own
• Not the same as the inode
of the item
they are
pointing to
• Depend on
the existence
of the
destination
they are
pointing to
Summary
• UNIX was created to be a multiuser, multithreaded, secure OS
• The Linux kernel is usually packaged with other software components, such as a
GUI and applications
• Linux supports a wide range of file systems
• UNIX and Linux have four components defining the file system: boot block,
superblock, inode block, and data block
• In the Linux file system, a hard link is a pointer that allows accessing the same file
by different filenames
Ad

More Related Content

What's hot (20)

SSM
SSMSSM
SSM
Ramasubbu .P
 
NTFS and Inode
NTFS and InodeNTFS and Inode
NTFS and Inode
Amit Seal Ami
 
Ntfs and computer forensics
Ntfs and computer forensicsNtfs and computer forensics
Ntfs and computer forensics
Gaurav Ragtah
 
Windows File Systems
Windows File SystemsWindows File Systems
Windows File Systems
primeteacher32
 
ITFT_File system interface in Operating System
ITFT_File system interface in Operating SystemITFT_File system interface in Operating System
ITFT_File system interface in Operating System
Sneh Prabha
 
A fast file system for unix presentation by parang saraf (cs5204 VT)
A fast file system for unix presentation by parang saraf (cs5204 VT)A fast file system for unix presentation by parang saraf (cs5204 VT)
A fast file system for unix presentation by parang saraf (cs5204 VT)
Parang Saraf
 
NTFS file system
NTFS file systemNTFS file system
NTFS file system
Ravi Yasas
 
2nd unit part 1
2nd unit  part 12nd unit  part 1
2nd unit part 1
Pavan Illa
 
Introduction to file system and OCFS2
Introduction to file system and OCFS2Introduction to file system and OCFS2
Introduction to file system and OCFS2
Gang He
 
Linux and windows file system
Linux and windows  file systemLinux and windows  file system
Linux and windows file system
lin yucheng
 
File System Interface
File System InterfaceFile System Interface
File System Interface
chandinisanz
 
M2 211-unix fs-rl_2.1.1
M2 211-unix fs-rl_2.1.1M2 211-unix fs-rl_2.1.1
M2 211-unix fs-rl_2.1.1
MrudulaJoshi10
 
File System Implementation
File System ImplementationFile System Implementation
File System Implementation
Abhishek Pachisia
 
Ch11
Ch11Ch11
Ch11
tech2click
 
File structures
File structuresFile structures
File structures
Shyam Kumar
 
Learn about log structured file system
Learn about log structured file systemLearn about log structured file system
Learn about log structured file system
Gang He
 
File implementation
File implementationFile implementation
File implementation
Mohd Arif
 
file system in operating system
file system in operating systemfile system in operating system
file system in operating system
tittuajay
 
Windows Registry
Windows RegistryWindows Registry
Windows Registry
primeteacher32
 
File system
File systemFile system
File system
sonu riyana
 
Ntfs and computer forensics
Ntfs and computer forensicsNtfs and computer forensics
Ntfs and computer forensics
Gaurav Ragtah
 
ITFT_File system interface in Operating System
ITFT_File system interface in Operating SystemITFT_File system interface in Operating System
ITFT_File system interface in Operating System
Sneh Prabha
 
A fast file system for unix presentation by parang saraf (cs5204 VT)
A fast file system for unix presentation by parang saraf (cs5204 VT)A fast file system for unix presentation by parang saraf (cs5204 VT)
A fast file system for unix presentation by parang saraf (cs5204 VT)
Parang Saraf
 
NTFS file system
NTFS file systemNTFS file system
NTFS file system
Ravi Yasas
 
2nd unit part 1
2nd unit  part 12nd unit  part 1
2nd unit part 1
Pavan Illa
 
Introduction to file system and OCFS2
Introduction to file system and OCFS2Introduction to file system and OCFS2
Introduction to file system and OCFS2
Gang He
 
Linux and windows file system
Linux and windows  file systemLinux and windows  file system
Linux and windows file system
lin yucheng
 
File System Interface
File System InterfaceFile System Interface
File System Interface
chandinisanz
 
M2 211-unix fs-rl_2.1.1
M2 211-unix fs-rl_2.1.1M2 211-unix fs-rl_2.1.1
M2 211-unix fs-rl_2.1.1
MrudulaJoshi10
 
Learn about log structured file system
Learn about log structured file systemLearn about log structured file system
Learn about log structured file system
Gang He
 
File implementation
File implementationFile implementation
File implementation
Mohd Arif
 
file system in operating system
file system in operating systemfile system in operating system
file system in operating system
tittuajay
 

Viewers also liked (20)

Social Media Forensics for Investigators
Social Media Forensics for InvestigatorsSocial Media Forensics for Investigators
Social Media Forensics for Investigators
Case IQ
 
Web Browser Artifacts
Web Browser ArtifactsWeb Browser Artifacts
Web Browser Artifacts
primeteacher32
 
Virtual Machine Forensics
Virtual Machine ForensicsVirtual Machine Forensics
Virtual Machine Forensics
primeteacher32
 
Web Scraping
Web ScrapingWeb Scraping
Web Scraping
primeteacher32
 
Processes
ProcessesProcesses
Processes
primeteacher32
 
Logs = Accountability
Logs = AccountabilityLogs = Accountability
Logs = Accountability
Anton Chuvakin
 
Cron Jobs
Cron JobsCron Jobs
Cron Jobs
primeteacher32
 
Open source
Open sourceOpen source
Open source
Vigno Raj
 
Regular Expressions
Regular ExpressionsRegular Expressions
Regular Expressions
primeteacher32
 
CSV File Manipulation
CSV File ManipulationCSV File Manipulation
CSV File Manipulation
primeteacher32
 
Processing Regex Python
Processing Regex PythonProcessing Regex Python
Processing Regex Python
primeteacher32
 
Unix Administration 2
Unix Administration 2Unix Administration 2
Unix Administration 2
Information Technology
 
مقدمة وتمهيد - Charisma Code كاريزما كود
مقدمة وتمهيد - Charisma Code كاريزما كود مقدمة وتمهيد - Charisma Code كاريزما كود
مقدمة وتمهيد - Charisma Code كاريزما كود
Ahmad Salameh
 
استعدادات السفر
استعدادات السفراستعدادات السفر
استعدادات السفر
sis shiraviolet
 
Part 03 File System Implementation in Linux
Part 03 File System Implementation in LinuxPart 03 File System Implementation in Linux
Part 03 File System Implementation in Linux
Tushar B Kute
 
Unix Linux Commands Presentation 2013
Unix Linux Commands Presentation 2013Unix Linux Commands Presentation 2013
Unix Linux Commands Presentation 2013
Wave Digitech
 
Reading and Writing Files
Reading and Writing FilesReading and Writing Files
Reading and Writing Files
primeteacher32
 
Terminal Commands (Linux - ubuntu) (part-1)
Terminal Commands  (Linux - ubuntu) (part-1)Terminal Commands  (Linux - ubuntu) (part-1)
Terminal Commands (Linux - ubuntu) (part-1)
raj upadhyay
 
Python Basics
Python BasicsPython Basics
Python Basics
primeteacher32
 
Linux administration
Linux administrationLinux administration
Linux administration
Yogesh Ks
 
Social Media Forensics for Investigators
Social Media Forensics for InvestigatorsSocial Media Forensics for Investigators
Social Media Forensics for Investigators
Case IQ
 
Virtual Machine Forensics
Virtual Machine ForensicsVirtual Machine Forensics
Virtual Machine Forensics
primeteacher32
 
Processing Regex Python
Processing Regex PythonProcessing Regex Python
Processing Regex Python
primeteacher32
 
مقدمة وتمهيد - Charisma Code كاريزما كود
مقدمة وتمهيد - Charisma Code كاريزما كود مقدمة وتمهيد - Charisma Code كاريزما كود
مقدمة وتمهيد - Charisma Code كاريزما كود
Ahmad Salameh
 
استعدادات السفر
استعدادات السفراستعدادات السفر
استعدادات السفر
sis shiraviolet
 
Part 03 File System Implementation in Linux
Part 03 File System Implementation in LinuxPart 03 File System Implementation in Linux
Part 03 File System Implementation in Linux
Tushar B Kute
 
Unix Linux Commands Presentation 2013
Unix Linux Commands Presentation 2013Unix Linux Commands Presentation 2013
Unix Linux Commands Presentation 2013
Wave Digitech
 
Reading and Writing Files
Reading and Writing FilesReading and Writing Files
Reading and Writing Files
primeteacher32
 
Terminal Commands (Linux - ubuntu) (part-1)
Terminal Commands  (Linux - ubuntu) (part-1)Terminal Commands  (Linux - ubuntu) (part-1)
Terminal Commands (Linux - ubuntu) (part-1)
raj upadhyay
 
Linux administration
Linux administrationLinux administration
Linux administration
Yogesh Ks
 
Ad

Similar to Examining Linux File Structures (20)

Types of files
Types of filesTypes of files
Types of files
Amar Jukuntla
 
operating system File - System Interface
operating system File - System Interfaceoperating system File - System Interface
operating system File - System Interface
Dr. Chandrakant Divate
 
Linux_File_System_Presentation________________________
Linux_File_System_Presentation________________________Linux_File_System_Presentation________________________
Linux_File_System_Presentation________________________
saurabhbquest
 
File System.pptx
File System.pptxFile System.pptx
File System.pptx
bcanawakadalcollege
 
Operating System File System IMpl lecture19.pptx
Operating System File System IMpl lecture19.pptxOperating System File System IMpl lecture19.pptx
Operating System File System IMpl lecture19.pptx
SuryaBasnet3
 
AOS Lab 10: File system -- Inodes and beyond
AOS Lab 10: File system -- Inodes and beyondAOS Lab 10: File system -- Inodes and beyond
AOS Lab 10: File system -- Inodes and beyond
Zubair Nabi
 
Systems Programming - File IO
Systems Programming - File IOSystems Programming - File IO
Systems Programming - File IO
HelpWithAssignment.com
 
os Module-4 ppt (1).pptx,...........................
os Module-4 ppt (1).pptx,...........................os Module-4 ppt (1).pptx,...........................
os Module-4 ppt (1).pptx,...........................
swathigandhi21
 
10 File System
10 File System10 File System
10 File System
Dr. Loganathan R
 
Operating system note of File System chapter .pptx
Operating system note of File System chapter .pptxOperating system note of File System chapter .pptx
Operating system note of File System chapter .pptx
maheshyadav5048
 
Ch10 file system interface
Ch10   file system interfaceCh10   file system interface
Ch10 file system interface
Welly Dian Astika
 
AOS Lab 9: File system -- Of buffers, logs, and blocks
AOS Lab 9: File system -- Of buffers, logs, and blocksAOS Lab 9: File system -- Of buffers, logs, and blocks
AOS Lab 9: File system -- Of buffers, logs, and blocks
Zubair Nabi
 
12-introductiontolinuxos-190907073928
12-introductiontolinuxos-19090707392812-introductiontolinuxos-190907073928
12-introductiontolinuxos-190907073928
SahilNegi60
 
12 introduction to Linux OS
12 introduction to Linux OS12 introduction to Linux OS
12 introduction to Linux OS
Hameda Hurmat
 
Os6
Os6Os6
Os6
gopal10scs185
 
Course 102: Lecture 5: File Handling Internals
Course 102: Lecture 5: File Handling Internals Course 102: Lecture 5: File Handling Internals
Course 102: Lecture 5: File Handling Internals
Ahmed El-Arabawy
 
Ext filesystem4
Ext filesystem4Ext filesystem4
Ext filesystem4
Neha Kulkarni
 
File system1.pptx
File system1.pptxFile system1.pptx
File system1.pptx
Samar954063
 
Linux_command_line_tutorial for begineers.pptx
Linux_command_line_tutorial for begineers.pptxLinux_command_line_tutorial for begineers.pptx
Linux_command_line_tutorial for begineers.pptx
csprakash6
 
UNIT III.pptx
UNIT III.pptxUNIT III.pptx
UNIT III.pptx
YogapriyaJ1
 
operating system File - System Interface
operating system File - System Interfaceoperating system File - System Interface
operating system File - System Interface
Dr. Chandrakant Divate
 
Linux_File_System_Presentation________________________
Linux_File_System_Presentation________________________Linux_File_System_Presentation________________________
Linux_File_System_Presentation________________________
saurabhbquest
 
Operating System File System IMpl lecture19.pptx
Operating System File System IMpl lecture19.pptxOperating System File System IMpl lecture19.pptx
Operating System File System IMpl lecture19.pptx
SuryaBasnet3
 
AOS Lab 10: File system -- Inodes and beyond
AOS Lab 10: File system -- Inodes and beyondAOS Lab 10: File system -- Inodes and beyond
AOS Lab 10: File system -- Inodes and beyond
Zubair Nabi
 
os Module-4 ppt (1).pptx,...........................
os Module-4 ppt (1).pptx,...........................os Module-4 ppt (1).pptx,...........................
os Module-4 ppt (1).pptx,...........................
swathigandhi21
 
Operating system note of File System chapter .pptx
Operating system note of File System chapter .pptxOperating system note of File System chapter .pptx
Operating system note of File System chapter .pptx
maheshyadav5048
 
AOS Lab 9: File system -- Of buffers, logs, and blocks
AOS Lab 9: File system -- Of buffers, logs, and blocksAOS Lab 9: File system -- Of buffers, logs, and blocks
AOS Lab 9: File system -- Of buffers, logs, and blocks
Zubair Nabi
 
12-introductiontolinuxos-190907073928
12-introductiontolinuxos-19090707392812-introductiontolinuxos-190907073928
12-introductiontolinuxos-190907073928
SahilNegi60
 
12 introduction to Linux OS
12 introduction to Linux OS12 introduction to Linux OS
12 introduction to Linux OS
Hameda Hurmat
 
Course 102: Lecture 5: File Handling Internals
Course 102: Lecture 5: File Handling Internals Course 102: Lecture 5: File Handling Internals
Course 102: Lecture 5: File Handling Internals
Ahmed El-Arabawy
 
File system1.pptx
File system1.pptxFile system1.pptx
File system1.pptx
Samar954063
 
Linux_command_line_tutorial for begineers.pptx
Linux_command_line_tutorial for begineers.pptxLinux_command_line_tutorial for begineers.pptx
Linux_command_line_tutorial for begineers.pptx
csprakash6
 
Ad

More from primeteacher32 (20)

Software Development Life Cycle
Software Development Life CycleSoftware Development Life Cycle
Software Development Life Cycle
primeteacher32
 
Variable Scope
Variable ScopeVariable Scope
Variable Scope
primeteacher32
 
Returning Data
Returning DataReturning Data
Returning Data
primeteacher32
 
Intro to Functions
Intro to FunctionsIntro to Functions
Intro to Functions
primeteacher32
 
Introduction to GUIs with guizero
Introduction to GUIs with guizeroIntroduction to GUIs with guizero
Introduction to GUIs with guizero
primeteacher32
 
Function Parameters
Function ParametersFunction Parameters
Function Parameters
primeteacher32
 
Nested Loops
Nested LoopsNested Loops
Nested Loops
primeteacher32
 
Conditional Loops
Conditional LoopsConditional Loops
Conditional Loops
primeteacher32
 
Introduction to Repetition Structures
Introduction to Repetition StructuresIntroduction to Repetition Structures
Introduction to Repetition Structures
primeteacher32
 
Input Validation
Input ValidationInput Validation
Input Validation
primeteacher32
 
Nesting Conditionals
Nesting ConditionalsNesting Conditionals
Nesting Conditionals
primeteacher32
 
Conditionals
ConditionalsConditionals
Conditionals
primeteacher32
 
Intro to Python with GPIO
Intro to Python with GPIOIntro to Python with GPIO
Intro to Python with GPIO
primeteacher32
 
Variables and Statements
Variables and StatementsVariables and Statements
Variables and Statements
primeteacher32
 
Variables and User Input
Variables and User InputVariables and User Input
Variables and User Input
primeteacher32
 
Intro to Python
Intro to PythonIntro to Python
Intro to Python
primeteacher32
 
Raspberry Pi
Raspberry PiRaspberry Pi
Raspberry Pi
primeteacher32
 
Hardware vs. Software Presentations
Hardware vs. Software PresentationsHardware vs. Software Presentations
Hardware vs. Software Presentations
primeteacher32
 
Block chain security
Block chain securityBlock chain security
Block chain security
primeteacher32
 
Hashes
HashesHashes
Hashes
primeteacher32
 

Recently uploaded (20)

Pixida, Simplifying Success in Germany, the USA, Brazil, China and Portugal
Pixida, Simplifying Success in Germany, the USA, Brazil, China and PortugalPixida, Simplifying Success in Germany, the USA, Brazil, China and Portugal
Pixida, Simplifying Success in Germany, the USA, Brazil, China and Portugal
TechMeetups
 
Software Development Business Plan1.pptx
Software Development Business Plan1.pptxSoftware Development Business Plan1.pptx
Software Development Business Plan1.pptx
vkprintingsolution
 
What's the Volume Quiz Presentation in Green Grey Purple Simple Lined Style (...
What's the Volume Quiz Presentation in Green Grey Purple Simple Lined Style (...What's the Volume Quiz Presentation in Green Grey Purple Simple Lined Style (...
What's the Volume Quiz Presentation in Green Grey Purple Simple Lined Style (...
shenleighmaemolina
 
Green Colorful House Simple Illustration Presentation.pdf.pdf
Green Colorful House Simple Illustration Presentation.pdf.pdfGreen Colorful House Simple Illustration Presentation.pdf.pdf
Green Colorful House Simple Illustration Presentation.pdf.pdf
RhyzCharmSolis
 
SAFETY BRIEFING.........................
SAFETY BRIEFING.........................SAFETY BRIEFING.........................
SAFETY BRIEFING.........................
BalaChandran458212
 
remakingyourselfpresentation-250430095415-6476ade1.pptx
remakingyourselfpresentation-250430095415-6476ade1.pptxremakingyourselfpresentation-250430095415-6476ade1.pptx
remakingyourselfpresentation-250430095415-6476ade1.pptx
lakhmanpindariya9176
 
Bronchitis_Presentation_with_Images.pptx
Bronchitis_Presentation_with_Images.pptxBronchitis_Presentation_with_Images.pptx
Bronchitis_Presentation_with_Images.pptx
monmohanchowdhury8
 
Career Planning After Class XII: Your Roadmap to Success
Career Planning After Class XII: Your Roadmap to SuccessCareer Planning After Class XII: Your Roadmap to Success
Career Planning After Class XII: Your Roadmap to Success
Dr. Radhika Sharma
 
GENERAL INFORMATION for the most beautiful
GENERAL INFORMATION for the most beautifulGENERAL INFORMATION for the most beautiful
GENERAL INFORMATION for the most beautiful
12213013
 
SHIPPING CONTAINdccdcdERS BC (2).pdf.pptx
SHIPPING CONTAINdccdcdERS BC (2).pdf.pptxSHIPPING CONTAINdccdcdERS BC (2).pdf.pptx
SHIPPING CONTAINdccdcdERS BC (2).pdf.pptx
ArshjotSingh30
 
Lecture 4.pptx which is need for microeconomic
Lecture 4.pptx which is need for microeconomicLecture 4.pptx which is need for microeconomic
Lecture 4.pptx which is need for microeconomic
mdrakibhasan1427
 
Science Lab Safety PPT.pptxwgyie ulbyaaaaaaaaaaaaaaaaaaaaaau
Science Lab Safety PPT.pptxwgyie ulbyaaaaaaaaaaaaaaaaaaaaaauScience Lab Safety PPT.pptxwgyie ulbyaaaaaaaaaaaaaaaaaaaaaau
Science Lab Safety PPT.pptxwgyie ulbyaaaaaaaaaaaaaaaaaaaaaau
atifkhan990367
 
Research Project csi1 - This presentation compares popular web browsers such ...
Research Project csi1 - This presentation compares popular web browsers such ...Research Project csi1 - This presentation compares popular web browsers such ...
Research Project csi1 - This presentation compares popular web browsers such ...
bomisung0207
 
Best Fashion Designing Colleges in Delhi
Best Fashion Designing Colleges in DelhiBest Fashion Designing Colleges in Delhi
Best Fashion Designing Colleges in Delhi
top10privatecolleges
 
Huckel_Molecular orbital _Theory_8_Slides.pptx
Huckel_Molecular orbital _Theory_8_Slides.pptxHuckel_Molecular orbital _Theory_8_Slides.pptx
Huckel_Molecular orbital _Theory_8_Slides.pptx
study2022bsc
 
RCM-billing in medical coding0000 1.pptx
RCM-billing in medical coding0000 1.pptxRCM-billing in medical coding0000 1.pptx
RCM-billing in medical coding0000 1.pptx
liajohn0808
 
!Warshauer Paul Curriculum Vitae, Resume
!Warshauer Paul Curriculum Vitae, Resume!Warshauer Paul Curriculum Vitae, Resume
!Warshauer Paul Curriculum Vitae, Resume
PaulWarshauer1
 
Employment Communication : The Job HUnting.pptx
Employment Communication : The Job HUnting.pptxEmployment Communication : The Job HUnting.pptx
Employment Communication : The Job HUnting.pptx
JunaidAlvi5
 
NATIONALISM IN EUROPE class 10 best ppt.pdf
NATIONALISM IN EUROPE class 10 best ppt.pdfNATIONALISM IN EUROPE class 10 best ppt.pdf
NATIONALISM IN EUROPE class 10 best ppt.pdf
leenamakkar79
 
HCollege ppt guidance and counselin.pptx
HCollege ppt guidance and counselin.pptxHCollege ppt guidance and counselin.pptx
HCollege ppt guidance and counselin.pptx
liajohn0808
 
Pixida, Simplifying Success in Germany, the USA, Brazil, China and Portugal
Pixida, Simplifying Success in Germany, the USA, Brazil, China and PortugalPixida, Simplifying Success in Germany, the USA, Brazil, China and Portugal
Pixida, Simplifying Success in Germany, the USA, Brazil, China and Portugal
TechMeetups
 
Software Development Business Plan1.pptx
Software Development Business Plan1.pptxSoftware Development Business Plan1.pptx
Software Development Business Plan1.pptx
vkprintingsolution
 
What's the Volume Quiz Presentation in Green Grey Purple Simple Lined Style (...
What's the Volume Quiz Presentation in Green Grey Purple Simple Lined Style (...What's the Volume Quiz Presentation in Green Grey Purple Simple Lined Style (...
What's the Volume Quiz Presentation in Green Grey Purple Simple Lined Style (...
shenleighmaemolina
 
Green Colorful House Simple Illustration Presentation.pdf.pdf
Green Colorful House Simple Illustration Presentation.pdf.pdfGreen Colorful House Simple Illustration Presentation.pdf.pdf
Green Colorful House Simple Illustration Presentation.pdf.pdf
RhyzCharmSolis
 
SAFETY BRIEFING.........................
SAFETY BRIEFING.........................SAFETY BRIEFING.........................
SAFETY BRIEFING.........................
BalaChandran458212
 
remakingyourselfpresentation-250430095415-6476ade1.pptx
remakingyourselfpresentation-250430095415-6476ade1.pptxremakingyourselfpresentation-250430095415-6476ade1.pptx
remakingyourselfpresentation-250430095415-6476ade1.pptx
lakhmanpindariya9176
 
Bronchitis_Presentation_with_Images.pptx
Bronchitis_Presentation_with_Images.pptxBronchitis_Presentation_with_Images.pptx
Bronchitis_Presentation_with_Images.pptx
monmohanchowdhury8
 
Career Planning After Class XII: Your Roadmap to Success
Career Planning After Class XII: Your Roadmap to SuccessCareer Planning After Class XII: Your Roadmap to Success
Career Planning After Class XII: Your Roadmap to Success
Dr. Radhika Sharma
 
GENERAL INFORMATION for the most beautiful
GENERAL INFORMATION for the most beautifulGENERAL INFORMATION for the most beautiful
GENERAL INFORMATION for the most beautiful
12213013
 
SHIPPING CONTAINdccdcdERS BC (2).pdf.pptx
SHIPPING CONTAINdccdcdERS BC (2).pdf.pptxSHIPPING CONTAINdccdcdERS BC (2).pdf.pptx
SHIPPING CONTAINdccdcdERS BC (2).pdf.pptx
ArshjotSingh30
 
Lecture 4.pptx which is need for microeconomic
Lecture 4.pptx which is need for microeconomicLecture 4.pptx which is need for microeconomic
Lecture 4.pptx which is need for microeconomic
mdrakibhasan1427
 
Science Lab Safety PPT.pptxwgyie ulbyaaaaaaaaaaaaaaaaaaaaaau
Science Lab Safety PPT.pptxwgyie ulbyaaaaaaaaaaaaaaaaaaaaaauScience Lab Safety PPT.pptxwgyie ulbyaaaaaaaaaaaaaaaaaaaaaau
Science Lab Safety PPT.pptxwgyie ulbyaaaaaaaaaaaaaaaaaaaaaau
atifkhan990367
 
Research Project csi1 - This presentation compares popular web browsers such ...
Research Project csi1 - This presentation compares popular web browsers such ...Research Project csi1 - This presentation compares popular web browsers such ...
Research Project csi1 - This presentation compares popular web browsers such ...
bomisung0207
 
Best Fashion Designing Colleges in Delhi
Best Fashion Designing Colleges in DelhiBest Fashion Designing Colleges in Delhi
Best Fashion Designing Colleges in Delhi
top10privatecolleges
 
Huckel_Molecular orbital _Theory_8_Slides.pptx
Huckel_Molecular orbital _Theory_8_Slides.pptxHuckel_Molecular orbital _Theory_8_Slides.pptx
Huckel_Molecular orbital _Theory_8_Slides.pptx
study2022bsc
 
RCM-billing in medical coding0000 1.pptx
RCM-billing in medical coding0000 1.pptxRCM-billing in medical coding0000 1.pptx
RCM-billing in medical coding0000 1.pptx
liajohn0808
 
!Warshauer Paul Curriculum Vitae, Resume
!Warshauer Paul Curriculum Vitae, Resume!Warshauer Paul Curriculum Vitae, Resume
!Warshauer Paul Curriculum Vitae, Resume
PaulWarshauer1
 
Employment Communication : The Job HUnting.pptx
Employment Communication : The Job HUnting.pptxEmployment Communication : The Job HUnting.pptx
Employment Communication : The Job HUnting.pptx
JunaidAlvi5
 
NATIONALISM IN EUROPE class 10 best ppt.pdf
NATIONALISM IN EUROPE class 10 best ppt.pdfNATIONALISM IN EUROPE class 10 best ppt.pdf
NATIONALISM IN EUROPE class 10 best ppt.pdf
leenamakkar79
 
HCollege ppt guidance and counselin.pptx
HCollege ppt guidance and counselin.pptxHCollege ppt guidance and counselin.pptx
HCollege ppt guidance and counselin.pptx
liajohn0808
 

Examining Linux File Structures

  • 2. Examining Linux File Structures • UNIX flavors • Silicon Graphics, Inc. (SGI) IRIX, Santa Cruz Operation (SCO) UnixWare, Sun Solaris, IBM AIX, and HP-UX • Linux distributions • Ubuntu, Debian, Red Hat, OpenSUSE, and Slackware • Linux is only the core of the OS • All UNIX-like OSs have a kernel • So do all Windows OSs
  • 3. Examining Linux File Structures
  • 4. Examining Linux File Structures
  • 5. File Structures in Ext4 • The early file system standard was Second Extended File System (Ext2) • Third Extended File System (Ext3) replaced Ext2 in most Linux distributions • Fourth Extended File System (Ext4) added support for partitions larger than 16 TB • Improved management of large files and offered more flexibility • Adoption of Ext4 was slower in some Linux distributions • Everything is a file • Files are objects with properties and methods
  • 6. File Structures in Ext4 Consists of four components • Boot block • Block is a disk allocation unit of at least 512 bytes • Contains the bootstrap code • UNIX/Linux computer has only one boot block, located on the main hard disk • Superblock • Indicates disk geometry, available space, and location of the first inode • Manages the file system • Inode blocks • First data after the superblock • Assigned to every file allocation unit • Data blocks • Where directories and files are stored • This location is linked directly to inodes
  • 7. Inodes • Contain file and directory metadata • Also link data stored in data blocks • An assigned inode contains the following: • Mode and type of file or directory • Number of links to a file or directory • UID and GID of the file’s or directory’s owner • Number of bytes in the file or directory • File’s or directory’s last access time and last modified timeInode’s last file status change time • Block address for the file data • Indirect, double-indirect, and triple-indirect block addresses for the file data • Current usage status of the inode • Number of actual blocks assigned to a file • File generation number of version number • Continuation inode’s link
  • 8. Inodes • First inode has 13 pointers • Pointers 1 to 10 are direct pointers to data storage blocks • Pointer 11 is an indirect pointer • Links to 128 pointer inodes and each pointer links directly to 128 blocks • Pointer 12 is a double-indirect pointer • Pointer 13 is a triple-indirect pointer • Bad block inode • Keeps track of disk’s bad sectors
  • 9. Hard Links and Symbolic Links Hard link • A pointer that allows accessing the same file by different filenames • Use the ln command to create a hard link Symbolic links • Pointers to other files and aren’t included in the link • Have an inode of their own • Not the same as the inode of the item they are pointing to • Depend on the existence of the destination they are pointing to
  • 10. Summary • UNIX was created to be a multiuser, multithreaded, secure OS • The Linux kernel is usually packaged with other software components, such as a GUI and applications • Linux supports a wide range of file systems • UNIX and Linux have four components defining the file system: boot block, superblock, inode block, and data block • In the Linux file system, a hard link is a pointer that allows accessing the same file by different filenames