boot linux installed on the external harddisk from the primary disk ?

['chris']

hi

howto boot linux installed on the external harddisk from the primary IDE disk ?

regards
chris

[Bojan Nemec]

Chris,

This depends on what you have on yours harddisk and what boot loader you use and what kind of external harddisk you have.

If you use the GRUB or LILO boot loader you can make a menu entry to boot from the external harddisk.

Warning! Before playing with boot loaders be sure to make a boot flopy and try it!

Can you give a litle more informations - Operating system residing on IDE harddisk, type of external harddisk and yours boot loader?

Bojan

[Steven E. Protter]

With the external disk plugged in.

Boot off a dos disk.

Then stick in a Norton Ghost disk or cd and type:

ghost

You should be able to do a complete disk to disk copy. That will probably leave you with a bootable external disk.

Of course you'll need to test that.

You may be able to achieve the same thing with mondo/mindi tool.

SEP

['chris']

sorry, I gave not enough information !

on the primary IDE harddisk is XP installed
with Windows Bootloader.

on the second external harddisk, connected via
USB I will install linux SUSE 9.1 with GRUB.

but this computer can not boot from USB
and I don't want to install any others bootloaders on the primary IDE hardddisc.

I mean to boot linux with Windows Bootloader.

normally, if linux is installed on the same
harddisk or on the second IDE harddisk it
works perfectly:

http://jaeger.morpheus.net/linux/ntldr.html

but if WINDOWS BOOTLOADER can boot linux from
an external harddisk ?

greetings
chris

[Steven E. Protter]

The Windows boot loader is likely to interfere with the GRUB loader. While its possible to make it work, for competitive reasons Microsoft didn't exactly provide a ton of documentation.

You can make it work easily with a third party product like Partition magic.

You can make it work with GRUB as the primary boot loader leaving over a NTFS parition and installing XP into that parition.

SEP

[Bojan Nemec · Accepted solution]

Chris,

I think this will be a hard work, if you want to leave the XP hard disk intacat.

One of possible solutions is to make a small partition on the primary harddisk (10M - 20M will be sufficient) and let the linux /boot directory to reside there. Now you can setup GRUB to chainload the Windows XP boot loader.

A second solution is to make a linux bootable floppy and boot from it.

In both cases you will need a kernel which have the USB support build in.

If you have a FAT partition (I think that GRUB does not support NTFS) on yours Windows XP, maybe, it will be possible to install the GRUB files on that partition and instruct the Windows XP boot loader to chainload the GRUB.

You will have to experiment. But remember to have a boot floppy handy. Some backups of yours boot blocks will be also very appereciated when you make a mistake. Linux dd is a great tool to make such backups.

Bojan

[Andrew Cowan]

I spent a lot of time trying to acheive something similar when I was migrating my setup to a new (larger) hard-disk. If you take a look at the Suse and Redhat support sites, they both say that they don't support having the boot-loader on one disk, and the root partition on another. In my case they were both internal IDE drives, so extra hardware support should not be an issue, however I never managed anything other than to boot from floppy.

You could make a small "/" partition and then put all your other slices on the other disk, and that works OK.

I also had a couple of strange problems when I ghosted the disk partitions over to my new drive. Even though I had edited the "/etc/fstab" and renamed the partitions, every couple of boots Linux hangs and the only way to recover it was to boot from floppy and re-format the swap partition of the old drive. Once I removed it every thing was fine.