In addition to a file manager, operating systems also include utility programs that one can use to manage disks and files. The list of such utility programs to manage disks and files is almost endless but here we provide some most common and important tasks.
Utility programs to manage disks and files
Disk formatting utility makes the disk ready to store data. Formatting creates a directory of the locations of each file called a file allocation table (FAT). When a user saves a file, the operating system stores it in a group of sectors, called a cluster, the smallest storage unit the computer can address.
To do so, it looks in the file allocation table for empty clusters and then stores the file in one of those locations. The address of the cluster where the file begins and the one where it ends are then listed in the file locations table.
The address of the cluster where the file begins and the one where it ends are then listed in the file allocation table. When a user opens the file, the operating systems use those addresses to locate the clusters and open the file stored in them.
When a user first users a disk, data are laid down in a linear fashion. Each part of a file is stored in adjacent clusters.
However, as a user begins to delete old files and add new ones, things begin to become less orderly, because fragments of files are scattered in clusters located in different areas on the drive to locate, save, and retrieve the fragmented files.
To fix this problem, a user needs to regularly defragment or defrag the disk. This procedure is often overlooked by computer users, who then wonder why their system gets slower and slower as time goes by.
In many cases, the system will even begin to misbehave; programs crash or files do not open. Often these problems can be fixed just by defragging the disk.
A newly manufactured disk is not always perfect. Some areas of the disk may not be usable. The manufacturer scans the disk and electronically marks bad areas as unusable so that no data are stored there.
As the user uses the disk, other areas may become bad. For this reason, a utility program is used to scan the disk at regular intervals to locate and mark any bad sectors. If this is not done, the operating system may store part of a file in them, and then the user will not be able to retrieve that part of the file. In addition, scanning finds and fixes problems with files.
For example, when systems crash, parts of files may be left scattered on the disk and become lost. The disk scanning program locates these lost clusters and stored them together in a separate file. In some cases, a user can open these files and recover lost work.
File deletion and recycle bin
Many of the files created by users on a computer eventually become outdated and no longer needed. To remove these files from the disk, users delete them. On many newer operating systems, this procedure does not actually delete them from the disk.
Instead, it moves them to a separate area of the disk called a recycle bin or trash can. If the user decides later that she/he wants to recover the file, she/he can open the recycle bin and restore it to the disk.
When absolutely certain that the user will never need the files in the recycle bin and restore it to the disk. When absolutely certain that the user will never need the files in the recycle bin, the user can make it empty.
This procedure deletes the files from the disk and one can no longer recover them. However, if a user ever deletes a really important file, it can also be restored.
There are programs that can recover deleted files, provided any subsequent commands did not place new files in the place on the disk where they are stored.
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