Organization of the file system
for each controlled operation. In the end, the Unix read, write and execute
monitored with the help of 9-bit (rwxrwxrwx). Abstract So, the file system,
there is a collection of files and directories, and operations on them. The
names, structures, files, how to access them and their attributes are important
aspects of the file system design. Most modern OS supports hierarchical system
of folders or directories, with the possible attachment directories. The
security of the file system is one of the most important concepts OS. The
interface file system. As already mentioned, the file system must organize
effective work with the data stored in external memory and the ability for a
user to remember and sample data in it. To arrange storage of information on a
disk the user normally performs his first formatting, providing a place for its
data structures, which describe the state of the file system as a whole. Then,
the user creates the necessary directory structure (or directory), which
essentially are lists of sub-directories and files itself. And finally, fills
the disk files, attributing them to a particular directory. Thus, the OS should
make available to the user set of services traditionally sold through system
calls, which provide: Creating a file system on drive operations necessary
to work with catalogs necessary for the operation of files In addition, file
services can address verification and preserve the integrity of the file system,
the problems of increasing productivity, and a number of others. Before
proceeding to the description of the various operations of file, it is necessary
to consider the key algorithms and data structures which ensure the functioning
of the file system. The general structure of the file system The system of data
storage disks can be structured as follows Lower-level equipment. This is
primarily magnetic disks with movable heads-key external memory devices, which
are in packages of magnetic plates (surfaces), among which at one lever moving a
package of magnetic heads. Step movement is a discreet package heads and every
situation package cylinder heads is logically consistent with the magnetic disk.
Cylinders are divided into tracks (tracks), and each track is marked on the same
number of blocks (sectors), so that each unit can be recorded on a maximum of
the same number of bytes. Therefore, the exchange works with a magnetic disk-level
equipment must specify the cylinder number, the number of surface units at the
relevant number and track the number of bytes you want to write or read from the
beginning of the block. Thus, the drives can be broken
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