[olug] System booting from software raid -- possible?

[Phil Brutsche]

Daniel Linder wrote:
> If I have three HDDs in a system configured in a RAID-5 setup, can I boot
> if the partitions (/(root) and /boot) are part of the RAID set?

It's not possible to boot from an md RAID0 or RAID5 volume - grub and
lilo aren't aware of things like striping or parity and won't be able to
access the kernel and the initrd/initramfs (if you use them).

What I would do is:

/dev/sda1: MD partition for RAID1 - /boot (150MB)
/dev/sda2: MD partition for RAID5 - / (10GB or so)
/dev/sda3: MD partition for RAID5 - LVM PV (all the rest)

/dev/sdb1: MD partition for RAID1 - /boot (150MB)
/dev/sdb2: MD partition for RAID5 - / (10GB or so)
/dev/sdb3: MD partition for RAID5 - LVM PV (all the rest)

/dev/sdc1: hot-spare MD partition for RAID1 - /boot (150MB)
/dev/sdc2: MD partition for RAID5 - / (10GB or so)
/dev/sdc3: MD partition for RAID5 - LVM PV (all the rest)

-- 

Phil Brutsche
phil at brutsche.us