Monday, June 16, 2008

Starting SafeBoot with GRUB

Installation of SafeBoot


SafeBoot can be installed over Tivoli. After installation, you need to authenticate on every boot and Windows will be started.
Only the partitions used by Windows will be encrypted, the Linux partitions are not affected.

Boot from a Rescue System


Booted my CentOS x86_64 with the installation DVD, giving on the boot-prompt linux rescue. This rescue system automatically detects my /-filesystem and all used partitions. The dialogs explain how to change to the installed system:
chroot /mnt/sysimage

Now you are prepared to backup SafeBoot and setup GRUB as default bootloader.
Note:
If your Linux is installed with a x86_64 version, you'll need a x86_64 rescue system.
Note:
It is adviced to use a CD or DVD for booting. A USB-Stick (which is emulated like a harddrive) could give troubles installing GRUB.

Backup the SafeBoot MBR


dd if=/dev/sda of=/boot/safeboot.mbr bs=512 count=1

The master-boot-record will be saved in the file called /boot/safeboot.mbr.

Install GRUB on the MBR


/sbin/grub-install /dev/sda

This overwrites the MBR with GRUB. By default GRUB will boot (no authentication needed).

Starting SafeBoot from GRUB


Edit /boot/grub/grub.conf (on Red Hat/CentOS) or /boot/menu.lst on other distributions. Add the next entry too the file:

title Microsoft Windows XP Professional
rootnoverify (hd0,0)
makeactive
chainloader (hd0,5)/safeboot.mbr

Here (hd0,0) is the Windows partition and /safeboot.mbr is the backup of the SafeBoot-MBR. In this case it is missing the /boot directory, as /boot is a seperate partition ((hd0,5) which is /dev/sda6).