Some simple Tricks

1. Create a Directory with different permission-: 

when we need a directory with specific permission , we created directory 
using the mkdir command then set the permission using chmod command.Define 
the access permission while creating the directory &  set permission. 
try to following command-: 
# mkdir /test -v -m 700 
where we used the -m option for define the permission,we need to set. Option 
v use for verbose mode. 

now check the directory permission. 
# ls -ld /test 

2. Take Hardware information on live server -:  Do you know Ram, Bious , 
Motherboard,processor,cache , slot status information form live server. We 
can use following command. 
# dmidecode --type bious 
# dmidecode --type processor 
# dmidecode --type memory