[LUNI] Setting up / on an LVM

[Trev Peterson]

Jay,

The system I have is:

/boot on md0 (raid1)
/ on md1 (raid1)
LVM on md2 (raid1 on one system and raid5 on another)
/var, /usr, /home, /tmp on the LVM Volume

I tested it with the / on the LVM and it complicates the process of
recovering from a boot CD (unless you customize the CD).  Most CDs I've
used don't load the md and lvm modules needed to activate the array and
I had to activate the array and volume group by hand.  Finally, the
filter for the lvm config had to be changed to filter out the raw drive
partitions (/dev/sda5) so the volume is built off the md device.
Mistakes with this can be costly (I tanked a test raid late one night
while testing it).  Having the / partition on a separate md (instead of
in an LVM volume) saves you these headaches.

I believe Martin recommended 500 Mb for the / partition and that sounds
about right.  Martin also recommended having /boot and / be the same
partition.  To be honest I can't think of any current reasons right now
not to do this.  I have always kept /boot on a separate partition but
that may be for reasons that no longer apply (legacy BIOS issues, etc).
I need to think about that when I am a bit more awake.

Hope this helps,

	Trev

On Wed, 2005-02-09 at 16:28 -0600, Jay Strauss wrote:
> 
> Trev, I just want to make sure I understand what you are saying.  Currently:
> 
> you have /boot on a mirror (md)
> The rest of your system, including "/", on a lvg on top of a mirror (md)
> 
> But you'd suggest, instead:
> 
> "/" and /boot on an (md) by themselves
> and put everything else on an lvg
> 
> Is that correct?
> 
> If so, my next question is, how big to make the / + /boot partition
> 
> Thanks
> Jay
-- 
Trev Peterson <trev at advanced-reality.com>
Advanced Reality