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ADN Informatique

Consultant Ingénierie Informatique

Saguenay (Jonquière), Québec, Canada. Tél: (581) 683-9887 Téléc: (581) 221-0874

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Linux Technique

2008-01-22 14:53:46 (ID: 43, Parent: 33, Type: page)
Linux Technicals
1 - Boot Loader 1.1 - Lilo 1.2 - Grub 1.3 - Others 2 - Kernel Compilation 3 - Programming language 4 - Configuration files 5 - DNS, Dynamic DNS
1 - Boot loader
What is a boot loader?  It's a small piece of code that allow booting your system.  Basicly, it load the first program needed to run your computer into memory and start it.
1.1 - Lilo Lilo is the most commonly used boot loader.  It came with about every linux distros.

1.1.1 - Playing with bios disk ordering to fake boot drive A common problem with booting the system (mainly with Ms ones) is that the computer BIOS is trying to start on the first drive.  The problem could be solved by swapping drive order. (fake d: is c: and c: is d:)  Lilo allow to do this very easyly.  There is an example:

map-drive = 0x80
to = 0x81
map-drive = 0x81
to = 0x82
map-drive = 0x82
to = 0x80

This system contain an ide drive (/dev/hda) wich have linux and lilo installed on.  It also contain two scsi drives (/dev/sda and /dev/sdb) that contain a bootable windows on drive /dev/sda.  This configuration tell the system to boot on drive /dev/sda (my windows) and map the first bios drive (0x80 which is reconized as c: under windows) to be the second one (0x82 that is the /dev/sda).  It also assign the second to be my third one and finally the third to be my ide.
Real config Faked config
bios 0x80 - MS  (but no active partition so can't boot) - /dev/hda bios 0x80 - MS c: (My MS bootable disk) - /dev/sda
bios 0x81 - MS c: - /dev/sda bios 0x81 - MS d: - /dev/sdb
bios 0x82 - MS d: - /dev/sdb bios 0x82 - MS not visible as linux disk - /dev/hda
Note that my windows was installed when there is no ide drive in my system, so using this fake configuration put my first scsi back in first position so MS Win could boot as previously installed. 1.2 - Grub 1.3 - Others 2 - Kernel compilation 3 - Programming language 4 - Configuration files 5 - Dynamic DNS

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Jean-Luc Cyr