The USB flash drive was a bit of a non-starter so, I decided to use a USB drive I had. As an aside, G-Technology make some good external drives, so if you’re ever in the market, they’re well worth a look. They cost a little more, but they use better bridge circuits (the bit between the USB connector and the drive’s SATA connection) and use Hitachi or HSGT drive mechanisms, making for a good solid choice for external storage. Historically, they were often found in studios as they always tended to have higher read / write speeds. I use Backblaze as a cloud based backup system and in their regular tests, HSGT often score highest for reliability.
I began imaging the drive with the .iso file and it failed, giving me some error about not being able to verify the image before restoring. This has plagued me for a few steps, so I decided to look into it some more.
Macs understand what an iso is, but generally prefer dmg files as image sources as they are able to checksum and verify them. What I had been doing is using either the downloaded iso image or a dmg created by the first (and only DVD) I made. That DVD was of Mate, which I had moved away from in favour of Lubuntu.
For whatever reason, Disk Utility would refuse to either convert the iso into a dmg for restoring (imaging) or verify the dmg in order to restore with it. It was becoming a little frustrating.
Some more research showed me use of Terminal and specifically, the dd command.
This would become the way I chose to image and although there are several steps, it really worked. I got this from OS X Daily
- 1. Connect the USB drive and let it mount up in Finder
- 2. Load Terminal
- 3. diskutil list
You get a list of drives and volumes, note the name (identifier) of the USB volume e.g. disk3s2
- 4. sudo umount /dev/(IDENTIFIER)
This unmounts the volume but not the drive so it can be prepped for imaging
- 5. sudo dd if=/path/image.iso of=/dev/r(IDENTIFIER) bs=1m
This is the actual imaging command
- 6. Enter the admin’s password and the computer goes off and does it’s thing. There isn’t a progress bar or anything, you just have to wait for the prompt to reappear. You could always load Activity Monitor to watch the disk activity.
- 7. Once the prompt shows, the disk can be ejected by typing diskutil eject /dev/(IDENTIFIER)