[CentOS] Advice on setting up Raid and LVM

Thu Mar 2 17:49:36 UTC 2006
Steve Huff <shuff at vecna.org>

On Mar 2, 2006, at 9:47 AM, Bowie Bailey wrote:

> Or you could do this:
>
> RAID 1 partition:
> md0 = 80GB (or whatever the useable total is)
>
> Then include md0 in VolGroup00 and create your logical volumes.
>
> LV0 = 300MB (/boot)
> LV1 = 500MB (swap)
> LV2 = 9.2GB (/)
> LV3 = 70GB  (/home)
>
> This way everything is mirrored and everything is in one VG.  If you
> need more space, add another pair of mirrored drives and add the new
> mirrored device into VolGroup00.  Then you can use the space to expand
> whichever filesystem needs it.  I would also advise following the
> previous poster's advice and leaving a few GB unused so that you
> aren't forced to add more drives immediately when LV2 fills up faster
> than you expected.

i was under the impression that GRUB doesn't know how to boot from a  
logical volume, and so the configuration you describe won't work  
without a bit of tweaking, like so:

two SW RAID 1 sets:
md0: 100MB, format as ext3, /boot
md1: the remaining space, mark as LVM

VolGroup00:
LV0 = 1GB swap
LV1 = 1GB /var
LV2 = 9.2GB /
LV3 = some more space for whatever you need

also, does anyone know if RHEL4 has fixed the problem of GRUB only  
being installed on the first drive of a SW RAID set?  refer to this  
doc for more discussion:

http://lists.us.dell.com/pipermail/linux-poweredge/2003-July/008898.html

-steve

---
If this were played upon a stage now, I could condemn it as an  
improbable fiction. - Fabian, Twelfth Night, III,v