Linux on a USB hard drive without USB-FDD BIOS option
 

I'm interested in buying a USB hard drive for my laptop so that I can run Linux on a separate drive--I have heard that dual boot on the same drive is problematic and furthermore I would have problems freeing up the space.

My BIOS has an option to boot to a USB-FDD, but not USB-HDD, so my questions are the following:

1) Does anybody know if there is a USB hard drive (_not_ a thumb drive) that can be booted using the USB-FDD BIOS option?

2) Otherwise, can I use a boot disk to load whatever pieces of Linux are necessary for USB into memory and just continue from there with the USB drive? If so, how do I set this up?

3) If #2 is possible, am I restricted to a distro like Knoppix?

Thanks a lot for your help.

You can boot from cd or floppy and then mount any supported hardware. The distro would not matter. Not sure about supported USB boot drives.

One drive is not a problem as far as I know. I have dual booted on a single harddrive many times.

Thanks, David

Is it enough just to be able to mount a drive? As I understand it, Linux is best run off a harddrive rather than a CD or floppy--won't I be stuck with a limited subset of my distribution, and won't it run slowly b/c I will be loading it off slow media and will lack swap space? I guess what I'm trying to ask it, is there any way that I can boot off a disk but have (most of) the operating system and swap partition located on a USB hard drive, or is there another way to achieve the same effect?

The /etc/fstab file tells the system what filesystems to mount at boot. You could also mount filesystems from the file that is run at boot from /etc/inittab. So the filesystem media can be anything that is supported hardware. The boot media should no longer be needed after everything is booted up and mounted USB is fairly slow itself.

Thanks again. Let me make sure that I have this completely straight: I can put any distribution I want on a USB hard drive and boot from a floppy disk but then mount the drive in time to load most of the operating system from it. The downside is that USB is slow.

Also, is there cd or disk image out there suited to this purpose--one that, in particular, loads the stuff I need for USB?

A floppy would work fine. In the bootloader you would have the drive partition as root...

root=/dev/???


Some distros have mkbootdisk, or check your distro for howto make a boot disk.

On the usb drive you would have the /boot folder which could be updated. Then your floppy would be updated by Lilo. At boot time the kernel is loaded and the floppy is no longer used until you boot again. In the bootloader config file you would have boot=/dev/fd0 to install the boot loader to the floppy when you run lilo. Lilo might be the best choice for a bootloader. In the bootloader config file you would have boot=/dev/fd0 to install the lilo to the floppy.


Or if you do an update of the kernel use mkbootdisk again, or the same method you used originally.

I've been trying to get this working for a while, with no luck. The boot disk that I get after running mkboot won't even boot--all it does is display 01 01 01 01 over and over again on my screen. I tried modifying the boot disk that comes with Knoppix (the image is on the CD) by putting my own kernel on there (I'm using Debian so I hoped it would be compatible on some level) and modifying the linuxrc file to insmod the USB modules but it just hangs.

So how do I go about setting up this /boot folder, and in particular how do I make a disk that will insert the proper modules and then "hand off" control to the harddrive? Why isn't mkboot working?