[wplug] LVM and RAID

[James O'Kane]

On Wed, 13 Nov 2002, Coutch, Robert wrote:
> Why should choose LVM over RAID? 

Because they do different things. In your case, the functionality seems to 
overlap, but LVM can do things like resizing of volumes and filesystems 
and I don't think RAID can.

> Is LVM useful for a single drive system?

Possibly. As above, if you partitioned things one way, and then you decide 
you need an extra 2 gigs for your / partition, you can resize things on 
the fly.
 
> I've heard a system runs faster with less partitions, any opinions?

eh. I don't think it matters all that much with recent hardware. My guess 
on why it might run slower with more partitions, is when it encounters a 
new mount point, it needs to check the superblock of that filesystem and 
start searching the directory structure of that device. If that is the 
reasoning for the concern, I wouldn't worry about it.
 
> If I use LVM on a single drive, should I make only a system partition and a
> swap partition then use LVM to create several virtual partitions? Why or why
> not? 
> 
> Does LVM affect system speed? I assume it does.


I can't say since I've not used it for much yet. I would point you to a 
post I made in April or so about EVMS, which is a beefed up version of LVM 
from IBM. It is available on sourceforge.

-james