I have a 250 gb HDD running Ubuntu 16.04 and I want to migrate its contents over to a new 250 gb SSD. I found this page, which gives pretty detailed instructions for doing do. First I wanted to ask if this is a good and up-to-date set of instructions, since I don't really know who wrote it and it was posted 5 years ago.
Assuming it is, I'm curious about a couple of things. For one, this is a pretty complicated set of steps. Why can't I just image the existing HDD (say, with DD) and restore it to a blank SSD?
Also the instructions say that after moving things over I have to reinstall Grub. Why do I need to do this if grub is already installed on the HDD?