linux v3.16.7-7-desktop x86_64
I wish to move the / (root) partition from a hard drive to a SSD. I presume I would need to boot to a Rescue System and … do something.
Once I have copied all of the files and directories, I can remake initrd, no problem
What is the best way to copy the root volume from one disk to another and have it bootable when it is done?
For the copying you need of course some sort of life system (rescue or whatever), because you can must have your root file system unmounted when copying. Your assumption about that is correct.
You should not forget to check (and change) every configuration place where your partition is mentioned, like /etc/fstab and in Grub. It depends on what identification is used there (/dev/disk/by-*), but it is very likely to be changed except wen you use by-label or by-uuid and cloned).