[CentOS] hardware RAID5 - MBR and default grub config on CentOS 4

Mon Aug 29 18:23:29 UTC 2005
Bryan J. Smith <b.j.smith at ieee.org>

Craig White <craigwhite at azapple.com> wrote:
> and yes, one of the things that Brian did assume correctly
> was /boot should be separately partitioned IF you use LVM -
> but even if you don't use LVM, it's still much easier to
fix
> things if /boot is on it's own partition.

I use LVM and put everything under it except / (root).

I typically make 3 primary partitions of equal size (1-8GB),
using one (typically /dev/sda3) for / (root).  I have a
standard 256MB DR-DOS 7.03 image I plop down (typically in
/dev/sda1) so I can boot a minimal setup for firmware
updates).  I leave

Primary partition #4 (/dev/sda4) is the LVM (slice type e8h).

> Brian ;^)   thanks for clarifying my incorrect terminology
> though.

Well, I can't exactly call it "incorrect," but it's confusing
without following the traditional references.  So I was
trying to clarify.

On the PC, the "Master Boot Record" (MBR) traditionally means
cylinder 0 (512KiB for sectors/heads of 63/16, 8MiB for
sectors/heads of 63/255) of the fixed disk targetted as BIOS
disk 80h (which GRUB calls hd0).

The "bootstrap" is then sector 0+ of any given slice that is
bootable.  The concept of a "bootstrap" is commonplace on
most architectures for a given OS install.

The concept of the "MBR" as part of the disk is definitely
PC/BIOS centric.  Other platforms use other methods to
transfer control from the firmware to disk.  In fact,
sometimes the loader that targets bootstraps is in the
firmware instead.


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