Of course - on the premade BeagleBone image, this software is all installed on it already. To run this command, you'd plug a USB cable into the BeagleBone, and then SSH to it by doing "ssh firstname.lastname@example.org" (It always has this IP) in a Terminal on macOS. Then you'd switch to root with "sudo su", and then "cd ~/mfm", then you can run the command above.
This command just creates the virtual hard disk with the size specified - once you've run this once, you don't need to do it again. You can also run this again to create a fresh image, or to have multiple virtual hard drives if you wanted to that you can swap out.
No, it is most certainly NOT normal. Voltages should climb up nearly instantly and remain steady at all times. There are many things in this power supply known to cause issues, and I remember running into a handful of threads where stability issues were being caused by a specific component that other members were trying to find functional substitutes for. I forget which threads they were, its been years.
So, you're telling me that fluctuating voltage isn't normal? Well that's a start, now let's find the problem! What could go wrong with the power supply?
I'm no expert in electrical circuits, but my tip is on the T3 transformer, last time I checked, it looked kinda fried up.
Then that click-click sector is a bad sector. It needs to be mapped in the bad table. Not sure how you can do that with Mac software, but I know you can do that with PC software. Once all known bad cylinders are stored in the preformatted bad table, that blocks them off from OS tools being able to use it. Then the drive will skip over that sector every time.