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Dual boot

antesla asked
I have installed on my first HD linux, and on my second HD Windows NT, but I don't know how to do a dual boot from linux.  Can anybody explain me?

Thanks a lot

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You can dual boot in several ways.
You can install LILO and add entries to Linux and WinNT in the LILO config file (/etc/lilo.conf).
Another way is to have the WinNT partition as the active one, and add an entry to Linux in the WinNT boot.ini file.

As You said that Lnx is in Your 1st disk then probably Lnx is the default OS. Is simple:
 - add an entry to Your /etc/lilo.conf file in the end of      the file. The entry is:

 - save the /etc/lilo.conf file. (You must be root)
 - run lilo. (probably /sbin/lilo).

If every thing were OK You can now boot both Lnx an WinNT.
Remember that /dev/hdb1 represents Your 2sd disk.(if it is an IDE one). If it is SCSI then probably change /dev/hdb1 to /dev/sdb1.


If WinNT is the default OS then go to Lnx. (this procedure requires that LILO must be installed in your Lnx partition)
In Lnx an logged as root type:

  $dd if=/dev/hda1 of=/bootsect.lnx bs=512 count=1

(remember that I'm assuming that You have installed Lnx in the /dev/hda1 partition. If You dont know then execute this command: $df and see in which FileSystem is Your / , it's easy! If it's not /dev/hda1 then substitute /dev/hda1 in the previous command ($dd ...) by what You have in the /'s FileSystem)

This will create a file, bootsect.lnx , in the / dir. Copy that file to a floppy. Go back to WinNT and edit the c:\boot.ini file. (cahnge permissions from read only to ...). add an entry at the end of the file. The entry is:


and save the file. (change again to read only)
And "voila"! Now You have both entries in the WinNT boot menu.

If You cannot access WinNT then You must mount the WinNT partition under Lnx. If You've installed WinNT under FAT, OK! You just create a dir like "$mkdir /dev/winnt" and then
execute "$mount /dev/hdb1 /mnt/winnt" (again I'm assuming that you have winNt in /dev/hdb1). Then, using some text editor, change the /mnt/winnt/boot.ini file like I said earlier. Copy the /bootsect.lnx file to /mnt/winnt/.
And there we go!

If You have installed WinNT in the NTFS, then I rather prefer the 1st method I said to You (the one that it's LILO who dual boot your Pc instead of the WinNt boot loader).

Hope it helps.

Feel free to ask more ...



Thanks for your help.  I have tried step by step to boot from linux, and to boot from the "boot.ini"option, but I cannot get good results.  
Is it necessary to activate mannualy all boot partitions? I have done this, but the same.
At the end, I have tried with "Boot Magic", from PQ, a boot manager.
But I would like to can do it from linux or NT.
NT partition is on NTFS.  Must it have anithing to see with this?
Thanks again.

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