Q: What’s the difference between Symbolic Link and HardLink?
　　A:  ln –s src dst-file 
 
    vs.  ln src-file dst-file
　　You need to understand how file is stored on the File System and what I-node is all about?

　　Each file contains 2 things:  file-name and structure that stores the real-data of the file.

　　Symbolic link is like: Added link to the filename only. It can cross device/logical partition.

　　Harlink is made at I-node(filesystem) level, it’s confined within the same filesystem(physical device). It’s more like adding a reference count to the original file, when hardlink is deleted, the reference minus one only.

　　Some people on the internet says this:

　　HardLink is a pointer to a file, Symbolic Link is an indirect-pointer to a file.

　　Since symbolic link can point to non-existent file on the disk, Hardlink can not.

　　Q:  How much do you know about journalized file system? Why Journalized File System(JFS)?
　　A:  Large HardDisk Partiion; quick recovery from crashes, high-performance I/O; Terabytes data file.

[1]  [2]