Re: Workarounds for advanced RAID features in GRUB Legacy?

[Tim Woodall]

On Sat, 10 Sep 2005, Leif W wrote:

> Specific areas:
>
> * RAID 1, RAID 10, RAID5
> * Partitionable RAID devices
> * Picking the most up-to-date drive
>
> Right now the cleanest option seems to be to simply put a separate ext2 
> partition at the beginning of each disc, have a kernel and initrd there to 
> handle the RAID setup, and install grub multiple times, and update everything 
> manually.  But I have SATA discs, which are treated like SCSI discs, and thus

What I've got is a raid1 /boot (md0) ext3 at the start of the disk and
then the rest of the disk is md1 which is then partitioned using LVM2.
(I'm just using raid1 on two IDE disks here)

And then my menu.lst looks something like this:

# Boot automatically after 30 secs.
timeout 10

# By default, boot the first entry.
default 0

# Fallback to the second entry.
fallback 1 2 3

# For booting Linux
title Linux-(hd0)
    root (hd0,0)
    kernel /vmlinuz root=/dev/vg0/root vga=791 hdb=ide-scsi
    initrd /initrd.img

# For booting Linux
title Linux-(hd1)
    root (hd1,0)
    kernel /vmlinuz root=/dev/vg0/root vga=791 hdb=ide-scsi
    initrd /initrd.img

<snip>


You still need to install grub into the boot sector on both disks but
once that is done then any updates will update both drives (except for
updating the boot sector or partition table)

If either drive fails then the system will boot from the other one (you
might need to unplug the failed disk to make the bios happy)

All of this is done using stock debian (sarge).

I've considered playing with making the entire disk raid1, including the
boot sector and partition table but I've never got around to it and I'm
not certain it can be made to work (easily).

Tim.

--
God said, "div D = rho, div B = 0, curl E = - @B/@t, curl H = J + @D/@t,"
and there was light.

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