I am running a remote centos 6.6, need to upgrade to 7 and feel there are too many chances that something could go wrong if I upgrade. Therefore, I am thinking about installing a second drive, then mounting an ISO so I can install centos 7 onto the new drive. However, before making it live, I need to be able to copy everything needed from sad1 first.
This is where things get unknown for me since I've not done a remote upgrade like this before.
I want to make sure I have installed everything I need into the new os, then I need to boot off the new drive, to make sure it is working as it should. If so, then I need to remove the old drive and leave the new one installed.
Since there will be two physical drives, I'm not sure how to deal with the drive designations.
For example, when I start, I'll have my first drive as sda1 and my second new drive as sdb1.
When I install, I'll want to install a boot loader onto sdb1 but at some point, that drive will become the only drive.
When the first drive is pulled out, will the second drive automatically become sda1 again and boot as it always has?