Rylan Cottrell a écrit :
To be able to boot of a usb drive you have to change the boot order. I have been able to boot my hp dv4000 with damn small linux. However for working with grub,I believe grub would have to be installed onto the main hd. And you would have to edited it manually to load the kernel from usb. It maybe easier to part the main hd into two segments and map the home drive and the windows desktop settings to the usb drive.
As I told below, I did exactly all that, booting from USB works without any problem and the first partition will be active, but I think that the other partitions on the usb disk won't be seen by the kernel before the completion of usb detection, it is the reason why I splitted windows XP and Linux between the two disks.
Hi, I tried such an experience this week with a HP ZD8000 laptop.
I tried to install windows and GRUB on the computer's hard disk and Linux on the USB disk, I met two difficulties :
1° Linux SuSE 10.1 installs very well, boots from the DVD with the option "boot the installed system", but doesn't boot by itself, the problem is that USB disks are not detected enough early in order to be mounted in time by the boot scripts, so BOOT failed.
2° I was able to install GRUB on hda with SuSE on sda but neither with Yast nor with grub-install, I had to use grub specific commands : root, find and setup
So this way could be usable but I've to modify the scripts embedded in initrd in order to wait for usb detection and to fill the dev folder ....too lazy ??
I didn't yet try to boot the computer from the usb disb (it is able to boot from usb) and to see if all its partitions are detected by the kernel, but I don't believe that !! I think I'll meet the same problem.
So at this time I installed a small part of windows and of Linux on the first disk with GRUB and the remainder on the usb disk. But take care if as myself you use 2 usb disks, they could be called either sda or sdb and fstab won't be able to work. So use in fstab the /dev/disk/by-id/nnn names, and it works. I'm even able to have the vmware partition on the usb disk if I use these names. Furthermore I wrote a script in order to mount some linux partitions after completion of the usb and udev work.
It's somewhat complicated but it works, I'm ready to adopt any other better solution.
Michel.