How to open udf disk. Recording formats for CD, DVD - Joliet, UDF, ISO. About optical disk file systems
The file system is the system that is used in the operation of the operating system. Windows system. It is necessary for organizing and storing data on any disk. It is she who is responsible for storing data on the hard drive. Let's look at what a file system is and what types of such systems exist.
Why do we need a file system?
You can understand what file system is used on your computer by going to the folder called “My Computer”. Then you need to click right click mouse and select “properties”. In the information window that appears, you can read the following inscription: File system: (name).
It is not at all necessary that each disk will have the same file system. To find out, you need to look at each disc.
It is on the correct choice of file system that the security of your personal computer, A operating system will not get confused and lose data. Let's look at what file systems can be found in Windows.
Types of file systems
FAT
The first thing we'll look at is a file system called FAT. Today it is extremely rare, so it is not worth dwelling on it in detail. Its biggest drawback is the maximum disk capacity, which is only 2 GB, which is practically never found in modern hardware. Thus, if your disk has a larger capacity, then it stops working. A few years ago, 2 GB was the standard hard drive capacity, and this file system was used perfectly there. But today it has outlived its usefulness and has taken an honorable place in the dustbin of history.
The next file system is the famous FAT 32. 32 is the system bit size. This version is an updated version of the previous file system. If you are using an earlier Windows version, then you may have some problems when formatting the disk. However, this system is much more stable than its predecessor, and working with files will proceed much faster.
NTFS
Now let's look at what the NTFS file system is. This system file storage appeared relatively recently and is more modern than the previous two. However, despite the huge number of advantages, it is not without its disadvantages. Most disks produced by commercial companies today have just such a file system. It stores data much better, but is quite demanding on your computer's resources.
Moreover, in the case when logical drive has a full load of up to 90 percent, the file system performance decreases sharply. Also, if the operating system is older than Windows XP, then such a file system will simply refuse to work on it. Once you insert a disk into the drive, your computer simply will not be able to recognize it or will be marked as an unknown partition. Speaking about the advantages, it can be noted that the work of such a file system with small files is much faster and of better quality. Most big size, which a disk can have is 18 TB. There is also such a thing as file fragmentation. With it, the file system will not slow down, but will continue to operate as usual. Also, when using NTFS, you can be completely and completely sure that file corruption will not occur. The system uses disk space very economically and allows you to compress files to minimum size, without spoiling them at all. By the way, it was thanks to this system that it became possible to restore data in case of loss. Accordingly, if we compare this system with FAT, then all the advantages are obvious. The most important thing that it can offer you is safety.
UDF
Now it’s time to look at what the UDF file system is. This is a file system that is independent of the computer's operating system and is used to save data stored on optical media. Unlike previous systems, UDF allows additional information to be written to an already full floppy disk. Also, this file system can selectively erase certain files on the disk without damaging other information. Metadata such as the root territory is located chaotically inside the disk, but the basis of this data has three places: sector 256, 257 and N-1, in this case N is the size of the track.
For DVD discs, UDF is the most successful file system because it has absolutely no restrictions on file sizes. You can record both large and small videos.
It was thanks to UDF that we learned what the final file system is and how to choose it correctly for your computer.
HFS extensions for Macintosh
Romeo extensions for Windows
Joliet extensions for Windows
Rock Ridge Extensions for UNIX
This extension was created to allow the UNIX file system to be represented on CD-ROM.
1. PX - POSIX attributes (standard bits rwxrwxrwx, (read, write, run) (owner, group, all))
2. PN - major and minor device numbers (so that you can write down the /dev directory, which contains the devices)
3. SL - symbolic link
4. NM - alternative name, allows you to use arbitrary names, without restrictions
5. CL - location of the child node (to bypass the restriction on nesting of directories)
6. PL - location of the child node (to bypass the restriction on nesting of directories)
7. RE - redistribution (to bypass the restriction on directory nesting)
8. TF - time stamps (time of creation, last change, last access)
This extension was created to provide the Windows 95 file system on a CD-ROM.
The System use field is used for this.
The extensions contain the following fields:
1. Long file names (up to 64 characters)
2. Set Unicode characters(support for various languages)
3. Overcoming restrictions on directory nesting
4. Directory names with extensions
The Romeo standard provides another option for burning files with long names to a CD. The name can be up to 128 characters long, but does not use Unicode. Alternative names are not created in this standard, so MS-DOS programs will not be able to read files from such a disk.
You can only select the Romeo standard if the disc is readable Windows applications 95 and Windows NT.
The hierarchical file system of Macintosh computers is not compatible with any other file systems and is called Hierarchical File System (HFS).
Originally created for DVD, version 1.50 added support for CD-RW and CD-R.
Now the latest version is 2.01. Official information(and specification) can be obtained from the server www.osta.org - server of the Optical Storage Technology Association.
This file system allows you to format a CD and work with it like a regular disk, copying, deleting and creating files.
Disadvantage: even smaller disk space (out of 700 MB, 550 MB remains).
13.2 CP/M file system
CP/M(Control Program for Microcomputers) - operating system, predecessor of MS-DOS.
Its file system has only one directory, with fixed entries of 32 bytes.
File names are 8+3 uppercase characters.
After each reboot, a bitmap of occupied and free blocks is calculated. The array is permanently located in memory (for a 180KB disk, 23 bytes of the array). After completion of work, it is not written to disk.
CP/M catalog entry
It can be seen that the maximum file size is 16KB (16*1KB).
For files between 16 and 32 KB in size, two entries can be used. For up to 48 KB three entries, etc.
Serial number records are stored in a field extent.
User code - each user could only work with their own files.
File reading order:
1. The file is opened with the open system call
2. The directory entry is read, from which it obtains information about all blocks.
3. The read system call is called
The operating system, which is the basis for the operation of any computer equipment, organizes work with electronic data, following a certain algorithm, in the chain of which the file system is not unclaimed. What is a file system in general, and what types of it are applicable in modern times and we will try to outline it in this article.
Description general characteristics file system
FS is, as stated above, a part of the operating system that is directly related to placement, deletion, movement electronic information on a specific medium, as well as the safety of its further use in the future. This resource is also applicable in cases where it is necessary to restore lost information due to a software failure as such. That is, it is the main tool for working with electronic files.
Types of file system
Each computer device uses a special type of file system. The following types are particularly common:
- intended for hard drives;
— intended for magnetic tapes;
— intended for optical media;
— virtual;
- network.
Naturally, the main logical unit of working with electronic data is a file, which means a document with information of a certain nature systematized in it, which has its own name, which makes it easier for the user to work with a large flow of electronic documents.
So, absolutely everything used by the operating system is transformed into files, regardless of whether it is text or images, or sound, or video, or photos. Among other things, drivers and software libraries also have transcriptions of them.
Each information unit has a name, a specific extension, size, inherent characteristics, and type. But the FS is their totality, as well as the principles of working with all of them.
Depending on what specific features are inherent in the system, it will work effectively with such data. And this is a prerequisite for classifying it into types and types.
A look at the file system from a programming perspective
When studying the concept of a file system, you should understand that this is a multi-level component, the first of which is dominated by a file system transformer, which ensures effective interaction between the system itself and a specific software application. It is he who is responsible for converting the request for electronic data into a specific format, which is recognized by the drivers, which entails effective work with files, that is, they are accessible.
Modern applications that have a client-server standard have very high FS requirements. After all modern systems are simply obliged to provide the most effective access to all available types of electronic units, as well as provide tremendous support for large-volume media, as well as establish protection of all data from unwanted access by other users, as well as ensure the integrity of information stored in electronic format.
Below we will look at all the existing FSs and their advantages and disadvantages.
FS - FAT
This is the oldest type of file system, which was developed back in 1977. It worked with OS 86-DOS and is not capable of working with hard storage media, and is designed for flexible types and storage of information up to one megabyte. If limiting the size of information is not relevant today, then other indicators remain in demand unchanged.
This file system was used by a leading developer company software applications– Microsoft for such operating systems as MS-DOS 1.0.
The files of this system have a number of characteristic properties:
— the name of the information unit must contain a letter or number at the beginning, and further contents of the name may include various computer keyboard symbols;
— the file name must not exceed eight characters; a dot is placed at the end of the name, followed by a three-letter extension;
— any keyboard layout register can be used to create a file name.
From the very beginning of its development, the FAT file system was aimed at working with the DOS operating system; it was not interested in saving data about the user or owner of the information.
Thanks to various modifications of this FS, it has become the most popular in modern times and the most innovative operating systems operate on its basis.
It is this file system that is capable of saving files unchanged if computer equipment is turned off incorrectly due to, for example, the battery not being charged or the lights being turned off.
Many operating systems with which FAT works contain certain software utilities that correct and check the file system content tree and files itself.
FS - NTFS
The modern NTFS file system works with the Windows NT operating system; in principle, it was aimed at it. It includes the convert utility, which is responsible for converting volumes from HPFS or FAT format to NTFS volume format.
It is more modernized compared to the first option described above. This version has expanded the capabilities with regard to direct access control to all information units. Here you can use many useful attributes, dynamic file compression, and fault tolerance. One of its advantages is its support for the requirements of the POSIX standard.
This file system allows you to create information files with names up to 255 characters long.
If the operating system that works with this file system fails, then there is no need to worry about the safety of all files. They remain intact and unharmed, since this type of file system has the property of self-healing.
A feature of the NTFS file system is its structure, which is presented in the form of a specific table. The first sixteen entries in the registry are the contents of the file system itself. Each individual electronic unit also has the form of a table, which contains information about the table, a mirror file in MFT format, a registration file used when it is necessary to restore information, and subsequent data - this is information about the file itself and its data that was saved directly on the hard drive.
All executed commands with files tend to be saved, which helps the system subsequently recover on its own after a failure of the operating system with which it is working.
FS - EFS
A very common file system is EFS, which is considered encrypted. It works with the Windows operating system. This system causes files to be stored on the hard drive in encrypted form. This is the most effective protection for all files.
Encryption is set in the file properties using a checkbox next to the tab indicating the possibility of encryption. Using this function, you can specify who can view files, that is, who is allowed to work with them.
FS – RAW
File elements are the most vulnerable units of programming. After all, they are the information that is stored on computer disks. They can be damaged, removed, hidden. In general, the user's work is solely aimed at creating, saving and moving them.
The operating system does not always show the ideal properties of its operation and has a tendency to fail. This happens for many reasons. But that’s not about that now.
Many users are faced with a notification that their RAW system. Is this really FS or not? Many people ask this question. It turns out that this is not entirely true. If we explain it at the level of a programming language, then RAW is an error, namely a logical error that has already been introduced into the Windows operating system in order to protect it from failure. If the equipment gives any messages about RAW, then you need to keep in mind that the structure of the file system is at risk, it is not working correctly or is in danger of gradual destruction.
If such a problem is evident, then you will not be able to access a single file on the computer, and it will also refuse to execute other operational commands.
FS – UDF
This is the file system for optical disks, which has its own characteristics:
— file names must not exceed 255 characters;
— the nominal case can be either lower or upper.
It works with the Windows XP operating system.
FS - EXFAT
And another modern file system is EXFAT, which is a kind of intermediary between Windows and Linux, ensuring the effective transformation of files from one system to another, since their file hosting services are different. It is used on portable storage devices, such as flash drives.
From what has been written above, we can draw the right conclusion. Each characterized file system has its own characteristics and creates certain file formats. This is why sometimes you cannot access some files, which means they were created in a completely different file system that yours cannot recognize.
We hope that the information presented in this article will help you avoid many problems when working with information files. Now you can independently determine which FS your computer’s OS works with, and what data you have to work with daily in the flow of their systematic operational processing.
Universal Disk Format UDF
The relatively new file system UDF (Universal Disk Format) was created by the Optical Storage Technology Association (OSTA) as an industry standard for optical media such as CD-ROM and DVD. The UDF format has a number of advantages over the ISO 9660 file system used by standard CD-ROMs. This format was developed directly for working with batch recording, i.e. with the technology of recording small amounts of data on CD-R/RW discs, and in general resembles the standard for recording data on magnetic media. The UDF file system supports file names up to 255 characters long. Batch writing software, such as DirectCD from Roxio and InCD from Nero AG, writes data to the UDF. However, standard CD-ROM drives, drivers and operating systems such as DOS cannot read CDs written in this format. UDF discs can only be read by CD-R/RW drives or conventional CD-ROM drives that meet the MultiRead specification.
First, you should check whether the existing drive reads UDF format disks, and then pay attention to the operating system used. In general, operating systems do not support disks of this format by default, so interaction with UDF is carried out by installing the appropriate driver. This applies primarily to Windows 95 and subsequent versions. MS-DOS does not accept UDF disks at all. UDF drivers are typically supplied with software, used by most CD-RW drives.
If you do not have a UDF disc reader, you can download one from the following sites.
- UDF Volume Reader from Roxio from www.roxio.com
- InCD Reader from Nero AG from www.nero.com
Once the UDF driver is installed, no additional steps need to be taken to read a disk formatted in this format. The driver will work in background, waiting for a UDF disk to be inserted.
If you cannot read a disk formatted with UDF or another system, go back to the original system and close the disk. This option usually appears when you perform a disc eject operation in a burning program. When closing the drive, all filenames will be converted to Joliet format and trimmed to 64 characters.
To download the latest version (2.60) of the Universal Disk Format system component, visit the OSTA website at:
www.osta.org/specs/index.htmAdvice!
UDF disks can become unreadable for a variety of reasons. An incompatible UDF reader may be installed, the disc may not be closed when removed from the drive, the table of contents may not have been written due to system failures, etc. To recover files from a UDF disk, try using CD Roller, available at www.cdroller.com. It supports the most common versions of UDF and is also capable of working with discs created digital cameras. Another disk recovery program can be called IsoBuster. Among other things, this program can work with Blu-ray and HD DVD discs.
UDF (Universal Data Format) is another file system for laser discs. It can be used on rewritable discs: CDRW, DVDRW, DVDRAM. The idea is to ensure work with rewritable laser discs as with hard drives or flash drives , i.e. provide the user with the ability to arbitrarily write and erase files and directories.
UDF file system closely related to batch recording . The first, “old” recording method involved the preliminary creation of a complete image of the entire disk or one session. Then this image was burned onto disk in one laser turn on using TAO methods(Track-At-Once, track at a time), DAO(Disc-At-Once, disk at a time) or SAO(Session-At-Once, session at a time).
The principle of packet recording is that areas of constant or variable length are pre-marked on the disk. Data packets are then written into them as needed, each of which begins with a header and contains a file or part of a file. As a result, each file or file fragment is stored in a separate package along with its description and can be erased or overwritten independently of the others. When erasing or writing subsequent packets, the area with tables of contents is read each time, modified in the computer memory, erased from the disk and written again in an updated form.
UDF requires packet write and read support at the drive firmware level. The operating system must have the UDF driver and batch recording software installed. In outdated OS, you should install the driver and program third party developers, for example, components of the Nero (InCD) or Roxio Creator (DirectCD) packages.
IN Windows Vista and Windows 7 for full UDF support there is a built-in driver, and the batch recording tool is integrated into Windows Explorer. However, you may be misled by the expression LFS (Live File System). For greater clarity, the Windows 7 developers called the implementation a “living file system” latest versions UDF file system. This abbreviation has the most indirect relation to LFS (logstructured file system, a file system of structured logs for BSD OS) and to the log file service (log file service, LFS in NTFS)!
For compatibility, a virtual table of contents VTOC ISO 9660 level 3 can be written to disk, as provided in the UDF Bridge specification. The VAT (Virtual Allocation Table) was introduced in version 1.50 of the UDF file system. If this element is missing or damaged, the operating system cannot detect files on the disk.
DVDVideo and DVDAudio discs use the microUDF file system (a subset of UDF, ISO 13346). The file size must not exceed 1 GB, and file names can be up to 255 Unicode characters long. Video files should be in the VIDEO_TS directory, audio files - AUDIO_TS. To protect against unauthorized copying, DVDVideo and DVDAudio discs can be encrypted with CSS. The UDF Bridge specification is a combination of ISO 9660 and MicroUDF.
Although batch recording is very convenient from the end user's point of view, in terms of recording reliability and data safety it is noticeably inferior to the session method. Chris Kaspersky ironically called UDF “the price to pay for thoughtlessness.” To transfer data from computer to computer, you can also format DVDRW to UDF (although network or flash drives are even more convenient and faster). However, to store data for long-term storage, it is recommended to burn discs “the old fashioned way”, using well-known and proven programs like Nero Burning ROM.