Hard link and Soft link ,date and cal cmd,

Hard Links soft link

H \=both original and hard files have same Inode number ,same size , same timestamp

if we delete original file there is no effect in hard link file ln file1 file2

S = It is pointer file to another file

if we delete original file there is effect in soft link file ln -s file1 file2

SYSTEM RESOURCES COMMANDS

Process Management Commands

ps : current running process

kill : kill the process

top : Display the linux tasks

sar : (system activity report) - It is used to collect the CPU ,Memory and I/O usage

Yum install sysstat –y (after installing it we can use sar command)

Archive/Data Backup Commands

How to create a zip files

Zip –rsample.zipsample1 (sample1 is directory name)