I am trying to resize the root partition folder from 50GB to 750GB. I have already increase the size of the drive. If I do an fdisk on /dev/sda and delete partition 2 and then recreate it the /dev/sda2 is resized correctly showing 999GB. When I then try to do a vgextend it gives an error saying, "can't open dev sda2 exclusively. mounted filesystem?" How can I increase the size of the root LVM partition? I attached screenshots of the different outputs for reference.
If I run: lvextend -l +100%FREE /dev/centos/root
It tells me it expanding from 50Gb to 50Gb.