Presentation on the topic "File. Computer file system"

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The file system determines the format of the content and physical storage of information, which is usually grouped in the form of files.

File system

A journaled file system keeps a constant record of all write operations to the disk (journal, log). Thanks to this, after a failure, the file system always automatically returns to a working state.

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File system

• FAT12/FAT16/FAT32 – unlogged file systems from the Microsoft campaign (Operating systems Windows 98 – 2000)
• NTFS – journaling file system from the Microsoft campaign (Operating systems WindowsXP and higher)
• Ext2/3 is a journaling file system designed for Linux OS

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File system

• ReiserFS is a journaling file system designed for Unix OS.
• HFS is a journaling file system developed by Apple Computer for Mac OS.
• CDFS is a file system for working with CDs and DVD discs. Based on ISO9660 standard.

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• Usually if HDD do not divide, it will be called C:
• If you divide it into two sections, these will be C: and D:

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Logical drives in Windows OS:

• Drive A:
• B: left for the second drive
• Two sections hard drive C: and D:
• DVD drive E:
• Flash drive F:

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• We will take care of the safety of information

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• A file (from the English word file - dossier, set of documents) is a certain amount of information (programs or data) with a name, stored in the long-term memory of a computer.
• Icons (pictures) indicating created files Microsoft Office 2007

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File characteristics:

Depending on the file system, a file may have a different set of properties.

• File name
• File type
• file size
• date of creation
• Starting cluster number

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File name:

• Abstract on computer science. DOC
• The file name is user defined.
• The name extension or file type is determined by the program in which it was created

In Windows OS, the following characters are prohibited in the file name:

• > < | ? * / \ : "
• A dot separates name and type

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File system

File types in Windows OS:

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• A directory (English directory - directory, index) is an object in the file system that simplifies the organization of files.
• Folder (English folder), Directory, Directory (equivalent concepts) - a special file containing information about other files (their names, location, etc.) Traditionally, in graphical mode it is displayed with a folder icon.

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• Current catalog
• Subdirectory
• Root directory

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File systems

• Rest
• Documentation
• Example.doc
• lesson.doc
• Drawings
• Snow.jpg
• sea.jpg
• Music
• concert.mp3
• game.iso
• Root directory is the main directory of the disk.
• A subfolder (subdirectory) is a folder located inside another folder.
• Folder (directory) – combines files and subfolders

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File system

• Documentation
• Rest
• Example.doc
• lesson.doc
• Drawings
• Snow.jpg
• sea.jpg
• Music
• concert.mp3
• game.iso
• D:\Recreation\Music\concert.mp3

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• DOCUMENTATION
• Act1.DOC
• Act2.DOC
• Figure 1.BMP
• Essay.DOC
• WORKS
• PHOTOS
• IVANOV.BMP
• ESSAY.DOC
• MAP.BMP
• DRAWINGS

Exercise. Write full file names.

Full file name:

• Disk name:\folder path\name.type

Let's check:

• E:\DOCUMENTS\ACTS\Act1.DOC
• E:\DOCUMENTS\ACTS\Act2.DOC
• E:\FIGURES\Figure1.BMP
• E:\Essay.DOC
• E:\WORKS\ESSAY.DOC
• E:\WORKS\MAP.BMP
• E:\PHOTOS\IVANOV.BMP

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Task (A6, GIA 9, 2011) The user worked with the catalog C:\Documents\Agreements\Sales First, he went up one level, then went down to the Urgent catalog, then went down to the Purchase catalog. Write down the full path of the directory where the user ends up.

Answer options:

• From:\Documents\Agreements\Sale - initially
• From:\Documents\Agreements - one level up
• From:\Documents\Agreements\Urgent - to the Urgent directory
• From:\Documents\Agreements\Urgent\Purchase – to the Purchase catalog

Slide 19

Task (A6, GIA 9, 2011) The user worked with the Archive catalogue. First it went up one level, then it moved to some subdirectory of the current directory, and again it moved to some subdirectory of the current directory. As a result, the user ended up in the C:\Data\Documents\2009 directory. Determine the fully qualified directory name where the user was originally located.

Answer options:

• C:\Data\Documents\2009 – ended up in the directory, go in the opposite direction
• C:\Data\Documents - left the directory for the first time
• C:\Data – left the directory for the second time, the user ended up in this directory when he left the Archive directory, and we need to go into it
• C:\Data\Archive

Slide 20

• Disk structure:(A) track(B) geometric sector(C) track sector(D) cluster
• Cluster - in some types of file systems, a logical unit of data storage in a file allocation table that unites a group of sectors.
• A cluster is the smallest disk space that can be allocated to store a file
• The concept of a cluster is used in the FAT, NTFS, FS Plus file systems. Other file systems operate with similar concepts (zones in Minix, blocks in Unix).

Slide 21

Logical structure of storage media in the FAT file system

1. Operating system boot record
2. File Allocation Table (FAT – File Allocation table). Contains complete information about the files located on the disk.
3. The files themselves.

• Full formatting - includes physical formatting (layout into tracks and sectors) and logical formatting, creating a file allocation table and root directory. After complete formatting, all information stored on the disk will be destroyed.
• Quick formatting only clears the file allocation table and the root directory. The files themselves are saved and, in principle, it is possible to restore the file system.

An external memory device divided into clusters.

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• The file occupies an integer number of clusters. White – free place, one color - one file
• As a result of work (erasing, copying, deleting), file fragments end up scattered across the disk.
• Defragmentation is the process of organizing files so that they lie without gaps

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• This is how various programs show defragmentation

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Let's say we created a file of 11 bytes in size.

• FAT16. The file will occupy 32 KB, because... cluster size 32 KB
• FAT32 or NTFS. The file will occupy 4 KB, because... cluster size 4 KB

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16 bits to store the cluster address.
216 = 65536 clusters.
1 cluster = 64 kilobytes
64 KB * 65536 = 4194304 KB = 4096 MB = 4 GB
4 GB – maximum disk size supported by the file system

32 bits to store the cluster address.
232 = 4,294,967,296 clusters.
1 cluster = 4 kilobytes
4 KB * 4,294,967,296 = 17,179,869,184 KB = 16,777,216 MB = 16,384 GB 16 TB
16 TB is the maximum disk size supported by the FAT 32 file system

Slide 26

A mask is a designation for a group of files.

When creating a mask use:

• *– any number of any symbols, including more than one
• ? – any one symbol must be present.

Masks are typically used to search or filter data. Most often - files.

We work with the console. We search for files using Windows.

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Exercise. Create a file mask.

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Abstract

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Slide 4. File systems for various platforms are listed.

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not presentations !

Best regards, Andrey Yudin.

�PAGE � �PAGE �1�

Presentation on the topic “File. Computer file system"

This presentation was originally created as illustrative material for Chapter 1.4 “File and File Systems” of the textbook “Informatics and ICT. Profile level" N.D. Ugrinovich, published in 2007 by the BINOM publishing house. But gradually, in the course of working with children, some questions were changed, removed or added.

The presentation turned out to be heavy, more than 2 MB, due to the large number of pictures inserted into it. But in this case, the end justifies the means. Since clarity when memorizing fairly complex questions on this topic gives quite high results than just text displayed on the screen. This presentation designed for several lessons.

It can also be used in regular classes, excluding some slides. Delete or hide (right click on the slide (hide slide).

The presentation contains 27 slides, one way or another illustrating issues related to the computer file system.

Slide 1. The definition of a file system is given.

Slide 2. The connection between the file system and the file is given. As well as the definition of a journaled file system.

Slide 3

Slide 4. File systems for various platforms are listed.

Slide 5. Shows the relationship between a physical and logical disk.

Slide 6. Shows how logical drives are named in Windows OS.

Slide 7. The issue of information security in case of problems with the OS is considered.

Slide 8. The definition of the file and its representation in the graphical operating system are given.

Slide 9. File characteristics are shown.

Slide 10. The concepts of file name and type (name extension) are given. It also shows which characters are prohibited in Windows OS in file names.

Slide 11. Shown is a table of the most common file types in Windows.

Slide 12. Definitions are given: Folder, Directory, Directory.

Slide 13. The concepts of root directory, subdirectory, and current directory are illustrated.

Slide 14. The diagram discusses the issues of nesting folders and files.

Slide 15. The file structure discussed on the previous slide is depicted as a tree. Shows how the full file name is formed.

Slide 16. Assignment for independent completion. Based on the tree shown on the slide, write down the full names of the files. After pressing any key, answers are displayed on the screen for students to check their work.

Slide 17. The solution to the problem on this topic from the GIA is considered. (A6, GIA 9, 2011.)

Slide 18. The solution to the problem on this topic from the GIA is considered. (A6, GIA 9, 2011.)

Slide 19. The concept of a cluster is illustrated.

Slide 20. The logical structure of the storage medium in the FAT file system is shown. Issues of full and quick formatting are considered.

Slide 21. The concept of disk defragmentation is given.

Slide 22. Screenshots of various programs showing a non-defragmented disk.

Slide 23. One of the disadvantages of file systems associated with a cluster is shown.

Slide 24. Calculation of the maximum disk size in various file systems is shown.

Slide 25. A definition of a file mask is given and examples where it is used are shown.

Slide 26. Examples of compiling file masks are considered.

Slide 27. Assignment for independent work of students. Self-test answers are displayed for each task separately.

For the presentation, I propose a small two-variant independent work on compiling file masks.

A large number of tasks included in the Unified State Exam, according to the file system, are located on the website of Konstantin Yuryevich Polyakov:

http://kpolyakov.narod.ru/school/ege.htm

They can be used not only when preparing for an exam, but also in regular lessons.

Unfortunately, I couldn’t find anything more on the Internet. If anyone knows other resources with tasks ( not presentations ! ) please give me a link to the address [email protected]

Best regards, Andrey Yudin.

What is a file?

• All programs and data are stored in the long-term (external) memory of the computer in the form of files.
• File- this is a certain amount of information (program or data) that has a name and is stored in long-term (external) memory.

• The file name consists of two parts separated by a dot: the actual file name And extension, defining its type (program, data, etc.).
• The actual name of the file is given by the user, and the file type is usually set automatically by the program when it is created.
• Example:
• proba.txt
• Units of information.doc

• Before the advent of Windows 95, most IBM PCs ran MS-DOS, which had very strict file naming rules. These rules are called agreement 8.3
• By convention 8.3, a file name can consist of two parts separated by a dot. The first part can be up to 8 characters long, and the second part (after the period) can be up to 3 characters long. The second part after the dot is called the name extension.
• When writing a file name, you are allowed to use only English letters and numbers. The name must begin with a letter. Spaces and punctuation are not allowed, with the exception of the exclamation mark (!), tilde (~), and underscore (_).

• After the introduction of the Windows 95 operating system, file naming requirements became significantly more relaxed. They are also valid in all subsequent versions of Windows operating systems.
• 1. Up to 255 characters are allowed.
• 2. It is allowed to use symbols of national alphabets, in particular Russian.
• 3. Spaces and other previously prohibited characters are permitted, with the exception of the following nine: /\:*?"<>|.
• 4. You can use multiple periods in the file name. The name extension is all characters after the last dot.

• Each storage medium (floppy, hard or laser disk) can store a large number of files. The order in which files are stored on the disk is determined by the installed file system.
• File system is a file storage and directory organization system.

• For disks with a small number of files (up to several dozen) it is convenient to use single-level file system, when the directory (disk table of contents) is a linear sequence of file names. To find a file on disk, you just need to specify the file name.

• If hundreds and thousands of files are stored on the disk, then for ease of searching, the files are organized into multi-level hierarchical file system, which has a “tree-like” structure (looks like an inverted tree).

• In order to find a file in a hierarchical file structure, you must specify the path to the file. The path to the file includes the logical name of the disk, written through the separator “\”, and a sequence of names of nested directories, the last of which contains the desired file.

• C:\Abstracts\
• C:\Abstracts\Physics\
• C:\Abstracts\Informatics\
• C:\Drawings\

• The path to the file along with the file name is called full file name.

• C:\Abstracts\Physics\Optical phenomena.doc
• C:\Abstracts\Informatics\Internet.doc
• C:\Abstracts\Informatics\Computer viruses.doc
• C:\Drawings\Sunset.jpg
• C:\Drawings\ Winter.jpg

• In the Windows operating system, the concept of “folder” is used instead of directories.
• Folder is a Windows object designed to group files and other folders into groups.
• The concept of a folder is broader than the concept of a “directory”. In Windows, at the top of the folder hierarchy is the Desktop folder. (The next level is represented by the My Computer, Recycle Bin and Network Neighborhood folders (if the computer is connected to a local network).

• Such actions with files as “create”, “save”, “close” can only be performed in application programs (“Notepad”, “Paint”, ...).
• The actions “open”, “rename”, “move”, “copy”, “delete” can be performed in the system environment.

• Copying (a copy of the file is placed in another directory);
• Move (the file itself is moved to another directory);
• Delete (the file entry is deleted from the directory);
• Renaming (file name changes).

• C:\My Documents\Ivanov\QBasic.doc
• C:\My documents\Petrov\Letter.txt
• C:\My documents\Petrov\Drawings\Sea.bmp
• C:\Movies\Interesting film.avi

• C:\Drawings\Nature\Sky.bmp
• C:\Drawings\Nature\Snow.bmp
• C:\My Documents\Report.doc

• C:\Drawings\Nature\Sky.bmp
• C:\Drawings\Nature\Snow.bmp
• C:\Pictures\Computer\Monitor.bmp
• C:\My Documents\Report.doc

Lesson topic: File and file systems

File

All programs and data are stored in the computer's long-term memory in the form of files.

A file is a program or data that has a name and is stored in long-term memory.

File name

The file name consists of two parts separated by a dot:

Example: Essay. doc

File name

The file name can include up to 255 characters (the Russian alphabet can be used), of which usually 3-4 characters are allocated for the extension.

File type: Extension:

Text files txt, rtf, doc

Graphic files bmp, gif, jpg, png

Sound files wav, mp3, midi, kar

File system

Each storage medium (floppy, hard or laser disk) can store a large number of files.

The order in which files are stored on the disk is determined by the installed file system.

A file system is a system for storing files and organizing directories.

For disks with a small number of files (up to several dozen), it is convenient to use a single-level file system, when the directory (disk table of contents) is a linear sequence of file names. To find a file on disk, you just need to specify the file name.

If hundreds and thousands of files are stored on a disk, then for ease of searching, the files are organized into a multi-level hierarchical file system, which is a system of nested folders (most often, instead of directories, the concept “folder” is used). Each folder can store lower-level folders, as well as files .

The path to the file

In order to find a file in a hierarchical file structure, you must specify the path to the file. The path to the file begins with the logical name of the disk (A, B - floppy disks, C, D, E, etc. - hard and optical disks.), then a sequence of names of nested folders is written, the last of which contains required file. Disk and folder names are written using a delimiter « \ »

E: \8 Class \ 8 A class \ F.I. \ - the path to the file

E: \8 Class \ 8A class \ F.I. \ Essay. doc - full file name

Find the file path and full file name

Actions with files

By using special programs- file managers - you can perform the following operations on files:

• copying;
• moving;
• deletion;
• renaming.

Using the programs win.zip, win.rar you can produce

• archiving files.

Formatting:

• Fast (clearing only the table of contents); Complete
• Fast (clearing only the table of contents);
• Complete (laying tracks and dividing into sectors).

Defragmentation .

Check your answers are correct!!!

C:\My documents\Ivanov\ QBasic . exe

C:\My documents\Petrov\Letter. txt

C:\My documents\Petrov\Drawings \ Sea. bmp

C:\Movies\Interesting film. avi

Assignment from the State Inspectorate - 9

The file work1.doc was stored in a certain directory. After creating a new subdirectory in this directory and moving the work1.doc file to the created subdirectory, the full file name became C:\

What was the full name of this file before it was moved?

• C:\document\9class\work1.doc work1.doc C:\document\work1.doc document\9class\math\work1.doc
• C:\document\9class\work1.doc
• work1.doc
• C:\document\work1.doc
• document\9class\math\work1.doc

Homework

§ 2.3, ex. 2.3 – 2.6, pp. 50 - 58