"Luigi Gangitano" <[EMAIL PROTECTED]> writes:
> Now the problem is: how should I use lilo to write the boot code in MBR on
> both disks? or how can I easily write the MBR on both disks so that it loads
> boot informations from a partition superblock (/dev/sda1 for MBR on /dev/sda
> and /dev/sdb1 for MBR on /dev/sdb)?
You need to write the MBR manually to both disks. But if you look at
the way the BIOS interfaces to the disk, you really want to write the
same MBR to both disks. As long as both disks work, you boot off sda,
which is the first bootable disk in the bios and thus is identified as
disk 0x80. When this disk crashes, your previous sdb disk now becomes
the first bootable disk, and is _also_ identified as disk 0x80 by the
bios. Since the kernel is situated in the same set of blocks on both
disks (raid1), lilo can issue the same set of instructions to the bios
to get hold of the kernel.
In short, you set up lilo to write to /dev/sda, and then you run 'dd
if=/dev/sda of=/dev/sdb bs=1b count=466' to copy the boot block from
sda onto sdb. (This assumes that sda1 and sdb1 (/boot mirrors) are
situated in the same cylinders on the disks, but using an identical
partition table makes sense, too... :)
-Harald
--
Harald Nordgård-Hansen, <>< http://bukharin.hiof.no/~hnh/ <>< Phone/Fax:
Østfold College, School of Computer Sciences, Norway <>< +47 6910 4033/4102
