On Fri, 5 Jun 2009 02:16:20 -0400, Philip Webb wrote:

> That's not how it works: you need to create the LVs with enough space
> for your likely needs & LVM then assigns them in its own way to the PVs;
> later, if you made an LV too small, you can increase it
> (you also have to extend the file system after you've done that,
> but of couse don't simply reformat the whole LV);
> if you want to decrease an LV -- rather unlikely in real life -- ,
> the problem is that you may risk losing data, if that part is dropped:
> I would imagine the correct procedure is to copy everything somewhere
> -- another LV, another partition, a USB stick -- ,
> then delete the LV & recreate it with the smaller size.

You shrink an LV in much the same way that you increase its size, except
in the opposite order - resize the filesystem and then the LV. It's not
difficult but it does take longer, because the filesystem resize
generally results in data being moved around. The main difficulty is that
you cannot shrink a mounted filesystem, so if you can't unmount it you
have to use a live CD to do the job.


-- 
Neil Bothwick

2 + 2 = 5 for extremely large values of 2.