Posted by ErmanArslansOracleBlog on Feb 18, 2016; 9:10am URL: http://erman-arslan-s-oracle-forum.124.s1.nabble.com/extend-partition-tp579p580.html
First of all, /dev/sda is a disk not a partition. /dev/sda1 is a partition.
This types of operations are risky and you have to know what you are doing. Methods are changing according to the OS and the filesystem.