5. Ease of use
Make it easier to recover a corrupted file system or operating system installation.
Performance
Smaller file systems are more efficient. You can tune file system as per application such as log or cache files. Dedicated swap partition can also improve the performance (this may not be true with latest Linux kernel 2.6).
Security
Separation of the operating system files from user files may result into a better and secure system. Restrict the growth of certain file systems is possible using various techniques.
Backup and Recovery
Easier backup and recovery.
Stability and efficiency
You can increase disk space efficiency by formatting disk with various block sizes. It depends upon usage. For example, if the data is lots of small files, it is better to use small block size.
Testing
Boot multiple operating systems such as Linux, Windows and FreeBSD from a single hard disk.
6.
It serves as 'backup' RAM. That is, should your computer run out of RAM, it will use the swap area as a temporary source of more memory, Swap space can be a dedicated swap partition (recommended), a swap file, or a combination of swap partitions and swap files. I wouldn’t recommend one over the other I believe that a balanced use of both is a good idea.
7. File system size, Extents, Delayed and Multi block allocation, Online defragmentation and fsck speed, Backward compatibility, Inodes / Timestamps and Persistent preallocation.

8. /etc/passwd file stores essential information, which is required during login i.e. user account information. /etc/passwd is a text file that contains a list of the system's accounts, giving for each account like user ID, group ID, home directory, shell, etc. 1. Username: It is used when user logs in. It should be between 1 and 32 characters in length. 2. Password: An x character indicates that encrypted password is stored in