OT: Revisiting LVM2

[Fairlight]

I have blasted LVM[2] as being an overly-complex subsystem that was not
worth its additional difficulty in return for meagre payoffs for all but
the biggest installations.

Okay, I'm eating my words.

I had cause the other night to move my entire in-house development system
from OpenSuSE to CentOS.  I already had a CentOS VM in VirtualBox, but it
was not used for anything except a testing sandbox, and as a client system
for a particular OpenVPN connection.  It really had half the disk space
that my OpenSuSE VM did (10GB as opposed to 20GB), and the OpenSuSE was
starting to get a bit tight in ways.

So it was particularly nice to be able to allocate a second VDI of 20GB,
issue two commands, and end up with a combined 30GB logical volume with
a (just about) 30GB filesystem on top of it, all without rescue disks or
anything of the sort.  Saved me a reinstall/reconfigure, and a bunch of
time and effort.

It also proved how easy LVM makes reprovisioning when you outgrow your
current provisioning unexpectedly.  Toss another drive (or disk image for
VMs) at it, and away you go in just a few minutes.  There are many ways
around the issue, including separate filesystems, creative use of symlinks
and data migration, and combinations of the two.  I've used these over the
years.  This simplicity and seamlessness trumps them--easily.

Okay, that -is- worth the trouble of learning a bit about how it works.
My opinion of the cost:benefit of LVM is hereby officially changed.

mark->
-- 
Fairlight->   ||| "Blend and balance, pain and       | Fairlight Consulting
  __/\__      ||| comfort deep within you / till you | http://www.fairlite.com
 <__<>__>     ||| will not want me any other way" -- | fairlite at fairlite.com
    \/        ||| Tool                               | (502) 509-3840