presented to: sir ahmad karim
DESCRIPTION
Presented to: Sir Ahmad Karim. Presented by: Tahmina Gillani (MIT-08-13) Mehwish saba (MIT-08-03) Hira Nargis (MIT-08-19) Misbah Fatima (MIT-08-12) Ayesha Raee (MIT-08-04). FILE SYSTEMS. File Names. - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: Presented to: Sir Ahmad Karim](https://reader035.vdocuments.us/reader035/viewer/2022062305/568147ff550346895db531ce/html5/thumbnails/1.jpg)
Presented to: Sir Ahmad Karim
Presented by: Tahmina Gillani (MIT-08-13) Mehwish saba (MIT-08-03) Hira Nargis (MIT-08-19) Misbah Fatima (MIT-08-12) Ayesha Raee (MIT-08-04)
![Page 2: Presented to: Sir Ahmad Karim](https://reader035.vdocuments.us/reader035/viewer/2022062305/568147ff550346895db531ce/html5/thumbnails/2.jpg)
FILE SYSTEMS
![Page 3: Presented to: Sir Ahmad Karim](https://reader035.vdocuments.us/reader035/viewer/2022062305/568147ff550346895db531ce/html5/thumbnails/3.jpg)
File Names
1 to 255 characters in lengthThis includes the path
You can use uppercase and lowercase (case-aware, but not case-sensitive)
You can use spaces and periods You cannot use these characters:
/ \ : * ? “ < > |
![Page 4: Presented to: Sir Ahmad Karim](https://reader035.vdocuments.us/reader035/viewer/2022062305/568147ff550346895db531ce/html5/thumbnails/4.jpg)
File Names continued
Filenames consist of two parts Main part of filename
Identifies the contents of the file
File extension Identifies the file type
The last period separates the file extension from the main part of the filename.
Windows typically associates a file extension with an application installed on a computer
![Page 5: Presented to: Sir Ahmad Karim](https://reader035.vdocuments.us/reader035/viewer/2022062305/568147ff550346895db531ce/html5/thumbnails/5.jpg)
Folder Names
Folder names follow the same guidelines for naming files
Folder names usually do not have a file extension
![Page 6: Presented to: Sir Ahmad Karim](https://reader035.vdocuments.us/reader035/viewer/2022062305/568147ff550346895db531ce/html5/thumbnails/6.jpg)
MS-DOS filename
Filename: 1 to 8 characters File extension: 1 to 3 characters DOS only uses uppercase You cannot use spaces A single period separates the file extension from
the filename You cannot use these characters:
/ \ : * ? “ < > | + = ; , [ ]
![Page 7: Presented to: Sir Ahmad Karim](https://reader035.vdocuments.us/reader035/viewer/2022062305/568147ff550346895db531ce/html5/thumbnails/7.jpg)
The Full Path
What does it mean?The complete path from the root of the files
system to the desired object.
Use \ (vs. /)C:\ - the root
C:\documents and settings\theresa\octc\cis110\filesystems.ppt
![Page 8: Presented to: Sir Ahmad Karim](https://reader035.vdocuments.us/reader035/viewer/2022062305/568147ff550346895db531ce/html5/thumbnails/8.jpg)
File Systems
A file system defines the structure and the rules used to read, write, and maintain information stored on a disk.
Which system used is determined by;HardwareSoftwareSecurity needsNeed for a dual-booting system
![Page 9: Presented to: Sir Ahmad Karim](https://reader035.vdocuments.us/reader035/viewer/2022062305/568147ff550346895db531ce/html5/thumbnails/9.jpg)
FAT???
file allocation table – where the OS records how the disk space is used
![Page 10: Presented to: Sir Ahmad Karim](https://reader035.vdocuments.us/reader035/viewer/2022062305/568147ff550346895db531ce/html5/thumbnails/10.jpg)
File Systems FAT 16 – oldest, created for DOS, supported by
most OSs’, cannot be installed on partitions larger than 2 GB, or on hard drives larger than 4GB.
FAT 32 – supports disks from 512 to 2TB, compatible with Windows 98 and up
NTFS – (new technology file system) – better file security (Encrypting File System), disk compression, logging features, reliability and stability. NTFS volumes can not be accessed by DOS, or Windows 95 or Windows 98.
![Page 11: Presented to: Sir Ahmad Karim](https://reader035.vdocuments.us/reader035/viewer/2022062305/568147ff550346895db531ce/html5/thumbnails/11.jpg)
File Systems
The operating system keeps track of data (documents, pictures, etc.) by placing it into a file.
To store and retrieve files: Disk divided into tracks Tracks are divided into sectors Sectors grouped into clusters
Number of sectors in a cluster is determined bySize of the hard driveFile allocation system – FAT, FAT32, NTFS
![Page 12: Presented to: Sir Ahmad Karim](https://reader035.vdocuments.us/reader035/viewer/2022062305/568147ff550346895db531ce/html5/thumbnails/12.jpg)
Tracks
Sectors within a
Track
Cluster
![Page 13: Presented to: Sir Ahmad Karim](https://reader035.vdocuments.us/reader035/viewer/2022062305/568147ff550346895db531ce/html5/thumbnails/13.jpg)
A hard disk has extremely smooth metal or glass plates called “platters” (vs. the floppy mylar disk of a floppy disk).
Each platter is divided into tracks and sectors by the format operation, like a floppy disk, however the number of tracks and sectors is different. The number of tracks on a hard disk depends on the disk size and the manufacturer.
![Page 14: Presented to: Sir Ahmad Karim](https://reader035.vdocuments.us/reader035/viewer/2022062305/568147ff550346895db531ce/html5/thumbnails/14.jpg)
A cluster, also known as an allocation unit, consists of one or more sectors of storage space, and represents the minimum amount of space that an operating system allocates when saving the contents of a file to a disk.
The number of sectors per cluster is dependent on Type of disk (floppy disk, hard disk) Version of operating systems Size of disk
Every sector contains 512 bytes. (NTFS does allow you to change this number.)
The number of clusters per disk is determined by the filing system (FAT 16, FAT 32 or NTFS).
Clusters?
![Page 15: Presented to: Sir Ahmad Karim](https://reader035.vdocuments.us/reader035/viewer/2022062305/568147ff550346895db531ce/html5/thumbnails/15.jpg)
DRIVE SIZEFAT 16
Cluster SizeFAT 32
Cluster SizeNTFS
Cluster Size
260 to 511 MB 8 KB (16 sectors) Not Supported 512 bytes (1 sector)
512 to 1023 MB 16 KB (32 sectors) 4 KB (8 sectors) 1KB (2 sectors)
1024 MB to 2 GB 32 KB (64 sectors) 4 KB (8 sectors) 2 KB (4 sectors)
2 to 4 GB 64 KB (128 sectors) 4 KB (8 sectors) 4 KB (8 sectors)
4 to 8 GB Not Supported 4 KB (8 sectors) 8 KB (16 sectors)
8 to 16 GB Not Supported 8 KB (16 sectors) 16 KB (32 sectors)
16 to 32 GB Not Supported 16 KB (32 sectors) 32 KB ( 64 sectors)
>32 GB (up to 2 TB) Not Supported 32 KB (64 sectors) 64 KB (128 sectors)
![Page 16: Presented to: Sir Ahmad Karim](https://reader035.vdocuments.us/reader035/viewer/2022062305/568147ff550346895db531ce/html5/thumbnails/16.jpg)
So, what does this all mean to us, as Windows XP users?
The bigger your disk – the bigger your clusters (because there is a maximum number of clusters per disk).
One way to help alleviate the problem of slack space is to partition the hard drive into smaller “drives”. Reducing the drive size will reduce the cluster size.
![Page 17: Presented to: Sir Ahmad Karim](https://reader035.vdocuments.us/reader035/viewer/2022062305/568147ff550346895db531ce/html5/thumbnails/17.jpg)
Which file system should you use?
If your computer runs only Windows XP and you do not plan to install other OS, use NTFS
However if you want to use other OS and you want to access the volumes you must use FAT16 or FAT32
![Page 18: Presented to: Sir Ahmad Karim](https://reader035.vdocuments.us/reader035/viewer/2022062305/568147ff550346895db531ce/html5/thumbnails/18.jpg)
OS and File System Compatibility
Operating System FAT16 FAT32 NTFS
Windows XP
Windows 2000
Windows NT
Windows 95, 98, ME
Windows 95
MS-DOS
![Page 19: Presented to: Sir Ahmad Karim](https://reader035.vdocuments.us/reader035/viewer/2022062305/568147ff550346895db531ce/html5/thumbnails/19.jpg)
What happens during the Formatting Process?
OS creates four tables in the 1st sectorsBoot Record – the name & version number of the OS, info. Master File Table #1- keeps track of
Available clustersClusters that contain dataClusters that are defectiveClusters that contain OS files
Master File Table #2 – copy of MFT #1Directory Table – top level folder and file information
![Page 20: Presented to: Sir Ahmad Karim](https://reader035.vdocuments.us/reader035/viewer/2022062305/568147ff550346895db531ce/html5/thumbnails/20.jpg)
Formatting Process, cont.
Full Format lays down new tracks and sectorsVerifies the integrity of each sector
By doing a surface scan – OS will put dummy data into sectors and then try to read the sector
Quick FormatRemoves filesDoes not check for defective sectors
![Page 21: Presented to: Sir Ahmad Karim](https://reader035.vdocuments.us/reader035/viewer/2022062305/568147ff550346895db531ce/html5/thumbnails/21.jpg)
Ext 3
Ext 3(third extended file system): Journaled file system used by Linux kernel. Introduced November 2001(Linux 2.4.15) Enhanced form of Ext 2 which Improve reliability Eliminates the need to check the file
system after an unclean shut down.
![Page 22: Presented to: Sir Ahmad Karim](https://reader035.vdocuments.us/reader035/viewer/2022062305/568147ff550346895db531ce/html5/thumbnails/22.jpg)
Advantages
Back up and restore data Less CPU power than other file systems in
Linux like XFS. More safer due to its relative simplicity and
wider testing base.
![Page 23: Presented to: Sir Ahmad Karim](https://reader035.vdocuments.us/reader035/viewer/2022062305/568147ff550346895db531ce/html5/thumbnails/23.jpg)
Cont’d
The ext3 file system adds, over its predecessor:
A journaling file system. Online file system growth. Htree indexing for larger directries.
![Page 24: Presented to: Sir Ahmad Karim](https://reader035.vdocuments.us/reader035/viewer/2022062305/568147ff550346895db531ce/html5/thumbnails/24.jpg)
Cont’d
Size limits: Maximum size for both indiviual files and
entire file systems. Max file size 16 GB – 2 TB. Max number of files:Variable,Allocated at
creation time. Max file name length:254 Bytes.
![Page 25: Presented to: Sir Ahmad Karim](https://reader035.vdocuments.us/reader035/viewer/2022062305/568147ff550346895db531ce/html5/thumbnails/25.jpg)
Journalling levels
Three levels in Linux implementation of Ext 3:
Journal(lowest risk) Ordered(medium risk) Writeback(highest risk)
![Page 26: Presented to: Sir Ahmad Karim](https://reader035.vdocuments.us/reader035/viewer/2022062305/568147ff550346895db531ce/html5/thumbnails/26.jpg)
Disadvantages
Functionality Defregmentation Recovery Compression NO checksumming in journal
![Page 27: Presented to: Sir Ahmad Karim](https://reader035.vdocuments.us/reader035/viewer/2022062305/568147ff550346895db531ce/html5/thumbnails/27.jpg)
Thanks for your
kind presence