On Mon, 2007-12-31 at 12:33 -0600, Mikkel L. Ellertson wrote: > John Austin wrote: > > > > The only real decisions are to do with how to boot. > > > > If the USB disk is to rely on the MBR of a main SATA/IDE type disk then > > choose the /dev/sdxy device associated with the USB disk at install > > time. > > Then add an entry to grub.conf on the fixed disk. > > title USB disk > > root (hdp,q) > > chainloader +1 > > > > In addition after install I would then configure grub on the MBR of the > > USB disk as well such that I can boot the disk with and without the > > presence of the "main", "fixed" disk. > > > What I did was install a copy of Grub to the MBR of the USB drive, > and then create an entry like this in the SATA Grub menu: > > title USB disk > root (hd0) > map (hd0) (hd1) > map (hd1) (hd0) > chainload +1 > > Because of the map commands, the USB drive is hd0 when the chainload > command is executed, and it loads Grub from the USB drive. (hd0 is > the entire disk, starting from the MBR.) From there it is the same > as if you had used the BIOS option to boot from the USB drive. The > only thing you have to be careful of is if you have more then one > USB drive plugged in. You will get a Grub error is the wrong one is > detected first, and does not have a boot loader on it. > > Mikkel > -- Hi Mikkel I liked your way of doing things but when I try on my machine as soon as I use the map command grub gets in a real muddle. It is not a problem to me but it should work !!!!!!!!! Even simple things from the grub command start failing Eg I can boot into interactive grub from SATA disk and re enter grub many times as follows With SATA=(hd0) USB=(hd1) (SATA is F8 x86-64, USB is F8 i386) both updated to within 3 days. Both have /dev/sdx1 = /boot, /dev/sdx2 = /, /dev/sdx3 = swap root (hd0) chainloader +1 re-enters the SATA grub menu root (hd1) chainloader +1 enters the USB grub menu root (hd1) chainloader +1 re-enters the USB grub menu root (hd0) chainloader +1 re-enters the SATA grub menu as soon as I do the following grub falls apart !!!!!!!!!! root (hd0) map (hd0) (hd1) map (hd1) (hd0) chainloader +1 Interesting ? John
