How to extend LVM based Filesystem in Linux?

A major question which came in Linux Administrators minds is that what will happen if all space within a crtical disk become full.
No worry! If you are using Linux LVM , then you can do it online as follows
1. Extend the space for LUN from storage subsystem management software

2. Rescan your partition table
#partprobe
3. Now the output of
#fdisk -l /dev/sdc

should show the extended size of Lun ( if not , then sorry your Linux kernel is not supporting online extension and you have to restart the server)

4. extend the pv
#pvresize /dev/sdc

5. extend the lv
lvextend -l 100% FREE /dev/VG01/lvdata01

6. Extend the fileystem

ext2online /dev/mapper/VG01/lvdata01

and to make sure finally verify through "df" command