Amazingly enough, circumstances have left me without a single USB flash drive, or a working CD-R drive. Also, because I moved about six months ago, I got rid of all my extra Ubuntu CDs that I used to get by mail. (cleanup win, hindsight fail) And yet, I need to get a live Ubuntu going to boot up a wonky desktop computer.
I tried using unetbootin to put a live CD install onto a portable USB hard-drive, but it won't boot from it (NTLDR missing error).
Is this because the disk is NTFS (which it is)? or for some other reason? Is there a difference between booting from a portable USB thumbdrive and a portable USB hard drive, other than potential performance?
There's no difference between a flash drive and a usb hard drive. Both can be used as a boot medium, and in the same way.
If you want to put the live system (installer) on the disk, the partition needs to be FAT32. NTFS cannot be read at this stage. So the partition you boot from (where the live cd contents are put) needs to be formatted as FAT32.
You can also install Ubuntu to the external hard drive, of course, just as you could with a flash drive. That's a different operation from using the drive as a live cd boot medium.
If you're talking about what I think you're talking about, running Ubuntu/Linux off of a external hard drive connected via USB then it's actually quite simple to do. Here are the steps, or rather, the steps I took.
Please Note: The following steps were tested using Ubuntu Version 9.10, but has not been tested with the later versions. Use at your own risk & discretion.
What You Will Need
What To Do
You can use
$ sudo aptitude install ubiquity
Install that on your machine (that's the-ubuntu-installer), then go through installation instruction make sure you set up partions on the usb-drive & at the last step select advanced and make sure the bootloader is installed on to usb-drive as well.
This will give you portable-ish Ubuntu on usb-drive. (ext4 etc.)
Currently the only tool that works for installing Ubuntu on NTFS is
wubi
but that's to be installed along with Windows.If the computer is attached to the Internet, then use Wubi.
http://wubi-installer.org/
Maybe somebody from the Israeli locoteam is nearby and can help you out with a live-CD or USB or such? Try the chat, forums, etc.