Greetings,
I just purchased two external, portable, USB 3.0 Hard Drives for my laptop PC. I've never done anything like this before, but I want to put a *nix distro of some kind on one and then use the other one for my data. I noticed that the boxes they both came in says they are for Windblows and Mac but I know they should work with any *nix distro just fine. The boxes also say they include pre-loaded backup software. I'd like to just wipe both hard disks clean and then, I guess format them (?) for use with *nix, and use the one with an OS to boot from my laptop and the other as just data storage. Will I be able to use my laptop then from the external USB hard disk with the OS on it if I then later wipe clean my laptops internal Hard disk? How would I wipe clean my laptops internal HDD? How do I format these two portable USB hard-disks in preparation for their new duties?

Thanks

First off, make sure that you can successfully boot from a USB device. There are some computers out there that still do not have the ability to do so. If you CAN boot off of a USB drive, then formatting them is simple.

If you boot off of the USB drive, then yes, you would be able to clear off the internal hard drive of the computer and run off of USB. However, this is probably going to be a performance hit, as your internal HDD might be a fast SSD or something similar.

Clearing off a USB device in preperation for linux is a matter of following some directions and getting some software from here:

http://www.pendrivelinux.com/yumi-mu...t-usb-creator/

Install that software, choose the distro you want and write it to the drive you want. That will allow you to install multiple linux iso's onto one USB for testing. Once you have the one you want, you can do a proper installation with 'dd' and the iso of your choosing.

If you want to install and boot from an external hard drive, you should be able to install to a partition on the external hard drive which you can create during the installation. You can also format the partition during the installation and you would need to install the bootloader of whichever distribution you want to the master boot record of the external hard drive. You could then select to boot that drive from the BIOS on each boot. Before anyone can give you any more specific advice, you would need to post information on what operating system you currently have on the laptop, whether or not you are using uefi and gpt partitioning.

I'm currently running Linux Mint 17 Cinnamon edition on my Dell Laptop. I have several USB flash drives (thumb drives) I suppose I could try to see if I can boot from one of those if that is a good test to see if I can boot from a USB device from this laptop. However, I have data on all my thumb drives so I have to figure out what to do with that first I guess. Let me see what I can do...

I visited the link provided and they show only 3 versions of Yumi. One for Windows, one for Ubuntu and one for Debian. I am currently running Linux Mint which is based on Ubuntu, which is based on Debian. So I guess I could go with either, but maybe I better choose Ubuntu version correct?

If you are running Mint 17, I expect it has some type of usb-creator although I don't know what it is called. There should be no real need to download other software. If you can't find it in Mint, then I would select the version for Ubuntu if you have that choice. Unetbootin is another piece of software which will do the job.

You can get unetbootin from apt-get & Synaptic Package Manager.
I use unetbootin to put installation disks on usb thumb drive.
I also keep a full install of debian on an external drive, which is quite useful. For my kernel image I selected all drivers so I can boot to most machines except UEFI & Mac.
If there's a problem I never have to chroot to repair a bootloader.
I just boot usb
update-grub
reboot to other os
unmount & remove usb
repair bootloader

Despite the fact that there was already a USB utility already installed on Linux Mint (one was called USB image writer the other called USB stick formater), I went ahead and downloaded and installed Unetbootin from Synaptic in Linux Mint that I'm using. When I launch it, it brings up a very small window and gives me a list of Distros that I can download at the top or specify an installation type below (whatever that means?). I see in the drop-down menu at the top it has a list of distros but it doesn't really have all that many to choose from nor does it have the one I'm wanting to try installing- OpenBSD. What should I do next?

There are instructions on the unetbootin page if you scroll down. The option at the top is if you want to download one of those distributions from the internet through unetbootin. If you already have an iso downloaded to your computer, then you need to click the tab to the far right of Disk Image, it has 3 dots in the center. That opens a window that you can use to navigate to where the iso is.

I'm not really sure what your plan is. If you are going to use unetbootin to install some Linux to an external hard drive, it will be the same as Live CD, meaning a read-only filesystem. Or were you planning to use unetbootin on a flash drive to install to the external drive. If the latter, you would have an actual rw installation.

The unetbootin home page has a long list of Linux distributions which have been tested and should work. It may be possible to get others not on the list to work. OpenBSD is not Linux, it is Unix based and probably won't work but, no harm in trying. I've not used it so good luck.

Most of the distro's listed are outdated. If you download a distro you can find it by pressing the box with 3 dots.

I would just install the distro to the usb hard drive making sure that it is the first in the hard drive boot order or remove power to internal. You don't have to prepare it. Once you have a single usb drive installed then you can go back and wipe the internal drive.