software raid

[Vu Pham]

David A. Bandel wrote:
[...]
> 
> No.  /boot only needs a different partition if you have an encrypted
> LVM (like my laptops).  All my servers (over a dozen) are software
> RAIDed and boot from the RAID partition using LILO (don't know if GRUB
> can do this or not).  The initrd.img must have the appropriate md
> drivers and mdadm code is all (and the paritions marked as fd, not
> 83), but that is handled on Debian systems and I would assume most
> others as well.
> 
> /etc/lilo.conf extract (when booting from mbr):
> 
> boot=/dev/md0  # my /boot directory
> root=/dev/md1  # my / directory
> raid-extra-boot=mbr-only  # needed for mbr booting
> 
> You will get warnings about sdb not being the first drive, but lilo
> must write both mbr's to ensure you can boot from the second drive if
> the first one fails (in which case sdb would become sda after breaking
> the mirror).  You would get more errors w/ RAID 5, but same goes as
> before -- you need to write all mbr's just in case).
> 

My RHEL server, using GRUB, has /boot on raid-1. Disk Druid told me if I 
set up /boot on RAID, then only RAID-1 can be used.


Grub config shows
         root (hd0,0)
         kernel /vmlinuz-2.6.18-53.el5PAE ro root=/dev/md2 rhgb quiet
         initrd /initrd-2.6.18-53.el5PAE.img

so I think the boot-loader, at boot time, just loads the kernel as if it 
is in a normal ext3 partition

Vu