[linux-lvm] finding the right size for rootvg

[<cmc2slack-lvm yahoo com>]

I'm re-installing slackware 9.1 on my linux box,
trying to set up LVM and ReiserFs. I'm pretty new
at this, learning as I go along.

I originally installed to another partition, now
I've creating a fresh partition and following the
LVM how-to about how to set up a root volume group. 
My questions are about partition and volume group size.

The first time I created a partition and PV I made
it 5GB and found that I had created the rootvg too
small by default to allocate enough space. So reading the
man pages I figured out that I need to specify a
certain extent size when I create the rootvg in order
to use the space properly. Right now the partition is
a little over 4GB and the rootvg is 3.97GB with an
extent size of 8MB. Is this small extent size a good
idea or will it cause problems later?

Thanks for any advice,