symbolic link

What is a symbolic link or shortcut?
A symbol link is a filename that links to another file. Consider the case on a UNIX box where three different mail packages are available. The administrator only wants to reference the mail using the command “mail”, so the filename is made to point to (or reference) the desired mail package. When the administrator runs the command “mail”, the appropriate mail package that is referenced by the symbolic link runs.
In Windows, a similar capability is known as a shortcut.

What is file-system integrity?
File-system integrity refers to whether the file-system contains errors. Sometimes this is caused by a user turning off the computer system without first shutting the computer down properly.
During the shutdown process, a flag can be written to the file-system. At startup, this flag can be detected, and if not present, means the computer system was not shut down correctly.
UNIX provides the fsck program to check the file-system. The Windows operating systems provide Scandisk or Chkdsk (checkdisk).

What is fragmentation and what does defragging a drive do?
When files are created and data written to the file, the operating system allocates space for the file from the free cluster list. Over a period of time, the clusters that are allocated to a file may no longer be sequential (contiguous or one after the after) but scattered over the disk.

Why is this a problem? An operating system reads data from secondary storage in contiguous clusters more efficiently and faster than from non-contiguous clusters.
Windows operating systems such as Windows 95/98 provide a defragmentation utility that scans the file system for fragmented files and moves them to a contiguous space. This results in faster loading and accessing of files.