Owlcom software
basadO wlCom  Software
Let's Owl manage your files
Welcome Screenshots Buy now Download Write to Owl Subscribe to news FAQ Links

The logical organization of the file system

two files have a simple name mam exe, but their names composite / depart / main.exe and / user / anna / main.exe different. In the tree-file system of file and its full name is available each one correspondence single file - a full name. In the file system of networking, the file can be included in several directories, and thus have more than one full names, this is true with one file - a lot of proper names. In both cases, the file is uniquely identified by full name. The file can be identified as a relative name. Relative file name is determined by the notion of current directory. For each user at a time, one of the directory file system is ongoing, and this directory is selected by the user on command OS. File system captures the name of the current directory, then use it as a complement to the relative name for the education of full file name. If you use relative file names the user identifies a chain of names of directories, which passes through the route from the current directory to the file. For example, if the current directory is a directory / user, then the relative file name / user / anna / main.exe as follows: anna / main.exe. Some operating systems are allowed to assign the same few simple file names, which can be interpreted as an alias. In this case, as in the system with the network structure, a line single file - a lot of proper names, because everyone simply the file name corresponds to at least one full name. And although the full name uniquely identifies the file, the operating system easier to work with the file if the files and their names have a mutually-one correspondence. To this end, it assigns a unique file name, so that the true relationship single file - a unique name. The unique name there, along with one or more character names assigned to files by users or applications. The unique name is a numeric identifier, and is intended only for the operating system. An example of such a unique file name is the inode number in UNIX. Mounting In general, the computer system may have multiple disk devices. Even a typical personal computer is usually a hard disk drive, a drive for floppy disks and storage for CD-ROM drive. Powerful computers are also typically equipped with a large number of disk drives, the drives are installed packages. Moreover, even a physical device through the operating system can be presented in several logical devices, in particular by partitioning space into sections. The question is how to organize files in a storage system with multiple external memory? The first solution is that in each of the devices available offline file system, that is, the files are on the device, described by the directory tree, not related to the directory trees on other devices. In this case for clear identification of the user files, along with a composite character file name to indicate a logical device identifier. An example of such an autonomous existence of the file systems is the operating system MS-DOS, which includes the full name of the file identifier of a logical drive letter. So, when you access files on a disk, the user must specify the name of the disk: A: \ privat \ letter \ uni \ let1 doc [1]. Another option is to store files such an organization in which the user is given the opportunity to combine file systems located on different devices into a single file system, described by a single directory tree. This operation is called mounting Consider how the operation is carried out by the example of operating system UNIX. Among all available in the logical disk devices, the operating system allocates one device, called the system. Suppose there are two file systems located on different logical drives, one of the disks is a system. File system, based on the system drive, appointed by the root. For communication hierarchies of files in the root file system selects some of the existing directory, in this example - a directory man. Upon completion of the selected directory mountpoints man becomes the root of the second file system. Through this directory assembled a file system is connected both to the general tree podderevo After mount a common file system for the user no logical distinction between the root and mounted file systems, in particular the naming of files produced in the same manner as if it had been from the beginning was a single.
Next part
Welcome    Screenshots    Download    Buy now Write to Owl    Subscribe to Owl news   FAQ   Links  
Copyright 2004-2008 OwlCom Software .

OISV - Organization of Independent Software Vendors - Contributing Member Software Submit .NET - FREE and PREMIUM search engines submission and software submission and software promotion service. Owl Commander
Locations of visitors to this page

Valid HTML 4.01 Transitional