linux. How to move the /opt folder to another partition?

Question

linux

Now the whole system is on sda1. On sda2 - swap. I want to transfer the /opt folder to sda3, because I make backup copies with acronis, and in the /opt folder android sdk, studio, gradle and a bunch of "heavy programs", without this folder, the backup will be done in a few minutes. Google helped a little. As I understand it, you need to boot from livecd, move all files from /opt to the /sda3 partition and edit fstab. But what will fstab look like then? Thank you.

Answer 1

mkdir /new_opt && mount /dev/sda3 /new_opt && mv /opt/* /new_opt/ && umount /new_opt &&  mount /dev/sda3 /opt  && rm /new_opt

I'm making a living. In /etc/fstab
where ext4 is /dev/sda3 file system