[kwlug-disc] LVM Questions

[Chris Irwin]

Quick question for any LVM geniuses out there:

I am looking at putting an SSD into my laptop. Since my wallet does
not allow me to get a SSD that would actually hold all of my data, I'm
looking at getting a caddy that will put the SSD in place of the
optical drive (which I don't use very often), thus I'll be able to
keep my high-capacity hard disk for less-frequently accessed, but
large media (isos, videos, etc), while keeping the system and /home on
the SSD for speed and battery life during regular use (i.e. when the
big disk is sleeping).

I would prefer to have both disks as part of a single volume group so
I can migrate logical volumes between them. My question is this: Will
LVM keep all extents of a particular logical volume together? Can I
just use the command below[1]? What about if/when I grow the disk?
Should I change my allocation policy[2]?

1. lvcreate -L 10G -n LVName VGName /dev/sda1
2. vgchange --alloc cling VGName

-- 
Chris Irwin
<chris at chrisirwin.ca>