1. Chapter 5 – Files, Directories, and the File System
CMIT100
Chapter 5 – Files, Directories, and the File System

2. Learning Objectives
Describe the elements of the file system from both the logical and physical viewpoint.
Identify various tools used to partition and format
Identify the differences between file systems utilized by various operating systems
Discuss common file system errors

3. Three File System Entities
Partitions
Volumes
Directories (or folders)
Files

4. Partition and Format
To setup the file system that will be used by the OS version you will be installing you must first partition and format the permanent storage device you will be installing to for that file system version.
Done during the installation process using the tools provided by the OS installation
Partition first, then format
Assuming that this is a “bare metal” or clean installation
Bare metal = brand new blank HDD (or SSD)
Clean install = using the OS installation partitioning tool, you have deleted the existing partitions
Linux systems are generally set up with multiple partitions. For example, Linux systems have a swap partition that functions like the page file on Windows. The swap partition is formatted with a different file system. You can set up partitions however you like with Linux, giving different system directories their own partition.
Windows refers to the partitions as volumes after the OS has been installed.

5. File Systems
File systems come in various versions and are different between OSs. Some common file systems include:
Windows OS:
FAT 32 – legacy file system used by Windows
Most UFDs and UHDs come formatted to FAT 32 for compatibility with mac OS
Newest version is exFAT
NTFS – current native file system used by Windows
mac OS:
HFS+ - used by current versions
Linux:
EXT – current version is 4
Linux systems are generally set up with multiple partitions. For example, Linux systems have a swap partition that functions like the page file on Windows. The swap partition is formatted with a different file system. You can set up partitions however you like with Linux, giving different system directories their own partition.
Windows refers to the partitions as volumes after the OS has been installed.

6. File Systems
File systems come in various versions, what does this mean?
If you connect a device partitioned and formatted to NTFS to a mac, can you read / write to the device? No
If you connect a device partitioned and formatted to HFS+ to a Windows system, can your read / write to the device?
Both Windows and mac OS can read / write to a device partitioned and formatted to FAT 32 (and exFAT) file system.
This is why manufacturers prepartition and format UFDs and UHDs to FAT 32.
Linux systems are generally set up with multiple partitions. For example, Linux systems have a swap partition that functions like the page file on Windows. The swap partition is formatted with a different file system. You can set up partitions however you like with Linux, giving different system directories their own partition.
Windows refers to the partitions as volumes after the OS has been installed.

7. File Systems There are some issues with using an older file system.
Best example:
NTFS has a much higher maximum single file size
FAT32 = 4 GB max. file size
NTFS = 16 TB max. file size
EXFAT = 16 EB max. file size
Wait… why would you ever need a file that is larger than 4 GB???
HAH! Think about it…
Linux systems are generally set up with multiple partitions. For example, Linux systems have a swap partition that functions like the page file on Windows. The swap partition is formatted with a different file system. You can set up partitions however you like with Linux, giving different system directories their own partition.
Windows refers to the partitions as volumes after the OS has been installed.

8. File Systems Which file system should you choose?
FAT32 – compatible with all current OSs, gaming consoles, and any device with a USB port
EXFAT – much larger single file size, compatible with Windows and mac OS, “optimized for UFDs”
NTFS – includes features that other file systems do not have:
Shadow copies for backup
Two levels of permissions = Share and Security (AKA NTFS)
Disk quotas
EFS = encrypted file system
Etc.
And, the only file system you can use for the %systemdrive%
%systemdrive% = the volume that you install the Windows OS to
Linux systems are generally set up with multiple partitions. For example, Linux systems have a swap partition that functions like the page file on Windows. The swap partition is formatted with a different file system. You can set up partitions however you like with Linux, giving different system directories their own partition.
Windows refers to the partitions as volumes after the OS has been installed.

9. File Systems Disk Quotas Encryption File Sharing and mapping
Set limits on how much space a user has on a particular volume
Most often used on network shares
Encryption
Encrypts a file based upon a user’s credentials
Even an administrator user cannot open a file encrypted by a different user
This capability is used by RansomWare
File Sharing and mapping
Sharing folders and files make them available on a network
Mapping a network drive assigns a drive letter to a shared folder

10. File Systems What if you need NTFS on a FAT32 device?
If you reformat the device, you will essentially lose all the existing files
Windows has a CLI command – CONVERT.EXE
Linux systems are generally set up with multiple partitions. For example, Linux systems have a swap partition that functions like the page file on Windows. The swap partition is formatted with a different file system. You can set up partitions however you like with Linux, giving different system directories their own partition.
Windows refers to the partitions as volumes after the OS has been installed.

11. Partition and Format Format, quick or full?
Quick = just clears the index created by the file system, doesn’t actually delete the files
Full = clears the index and does a basic test of all the allocation units created by the partitioning tool
Tests the storage device
Marks bad blocks on a HDD bad so the OS doesn’t write there

12. Partition and Format
To setup the file system that will be used by the OS version you will be installing, you must partition and format the HDD at the beginning of the installation
This is the partition / format tool used during an installation of Windows

13. Partition and Format This window shows that no partitions exist
Unallocated space
If you just click next the tool will create a partition that utilizes all of the available space
And format it to NTFS
Default is NTFS
Required is NTFS

14. Partition and Format But if you choose new…
You have the option of creating a partition that does not utilize the entire space on the HDD
Why would you do this?

15. Partition and Format
When you create a custom partition, you will be notified that a small system partition will be created
Created for boot files and repair files
Is not assigned a drive letter

16. Partition and Format End result… Clicking on format is not required
The system will automatically perform a “quick” format to the NTFS file system

17. Partition and Format A partition and format tool for installing Linux
Note the type called “swap”
This partition is used by Linux for the virtual memory files
Windows uses a file named PAGEFILE.SYS
Located in the root of the %systemdrive%
Linux systems are generally set up with multiple partitions. For example, Linux systems have a swap partition that functions like the page file on Windows. The swap partition is formatted with a different file system. You can set up partitions however you like with Linux, giving different system directories their own partition.
Windows refers to the partitions as volumes after the OS has been installed.

18. Partition and Format The Windows Disk Management console
Used to manipulate partitions on permanent storage devices in Windows
Create
Format
Shrink
Extend
Assign drive letters
Volume = a partition that has been assigned a drive letter
Linux systems are generally set up with multiple partitions. For example, Linux systems have a swap partition that functions like the page file on Windows. The swap partition is formatted with a different file system. You can set up partitions however you like with Linux, giving different system directories their own partition.
Windows refers to the partitions as volumes after the OS has been installed.

19. Partition and Format Using Gparted, an open source partitioning tool
Included with many different Linux distributions
Linux systems are generally set up with multiple partitions. For example, Linux systems have a swap partition that functions like the page file on Windows. The swap partition is formatted with a different file system. You can set up partitions however you like with Linux, giving different system directories their own partition.
Windows refers to the partitions as volumes after the OS has been installed.

20. Types of Files Plain Text Binary File Names Examples: .txt, .csv
Application files: .docx, .xlsx. .jpg, .mp3
Executable files: .exe, .com, .msi (windows), .dmg (mac OS)
File Names
Legacy 8.3 limitation in DOS
Some Linux distributions cannot use a _ (space) in a file name
Create zip file compare with archive.
A pointer is a value that designates the address (i.e., the location in memory), of some value. Pointers are variables that hold a memory location.

21. File Systems Hierarchical structure
Maps logical file name and physical location
Logical View:
Partitions, directories, files
Physical View:
File System Block on physical disk

22. Each platter has 64 sectors and 2048 tracks
Cylinder
Tracks
Sector
A subset of a track, similar
to wedge or a slice of pie.
You would reference a cylinder when you access the same tracks and sectors on all tracks simultaneously.
Each platter has 64 sectors and 2048 tracks
Each Surface is numbered starting with 0

24. File Systems File system issues Fragmented files
Files are written to many different sectors on a disk, over time, as files are deleted and new ones are written… a single file can be written to sectors that are spread out all over the disk.
Fragmentation of files slows down performance of the system
Defragging the files can increase performance
Windows has always had a built-in defrag tool
Newest versions of Windows run the defrag process automatically
Solid state drives (hard drives that use memory chips instead of spinning disks) should not be defragmented
Why?
MTBF

25. File Systems File system issues (cont.) Corrupted files
Applications can sometimes recover the files they have created
The NTFS file system has a minimal capability to recover from corrupted files
Corrupted system files
Windows has a CLI command to check for corrupted system files
SFC /SCANNOW

26. File Systems File system issues (cont.) Accidentally deleted files
Restore from Recycle Bin or the Trash on mac OS
Didn’t send to Recycle Bin?
Done by holding shift when clicking delete in Windows, or after you've emptied the Recycle Bin or Trash
Ooops… there are no undelete tools built in to Windows, some Linux distributions have them
mac OS?
There are free tools
Recuva from piriform.com

27. File Systems File system issues (cont.) Lost / corrupted volumes
Partition recovery tools do exist
Work well if you have accidently formatted a device
Get Data Back from runtime.org
Must be purchased for full functionality

28. Windows File System
File management tools
Windows File Explorer 


29. Windows File System
All files and folders start from the root directory
\ (whack) in Windows represents the root directory
%driveletter%\ - all permanent storages devices that you have created a volume on have a root directory
/ (slash) in Linux represents the root directory 


30. Linux File System Structure
BINlsgrepmv cp
SBIN ( Admin Tools)
Var ( kinda like temp where you find run time files. Spool files, files and locked files,logs)

31. Windows File System Structure
Sample
BINlsgrepmv cp
SBIN ( Admin Tools)
Var ( kinda like temp where you find run time files. Spool files, files and locked files,logs)