Alan McKinnon wrote:
Apparently, though unproven, at 12:48 on Saturday 09 April 2011, Dale did
opine thusly:
Yes.
PVs, VGs, LVs all have a concept of extend|resize|reduce. What that means
depends on what you are working with, but they all make the thing bigger or
smaller.
For a PV it means the underlying device's size changed, so the PV must change
to match. Take a 500G drive, create 1 partition on it of 100G and make it a
PV. Now enlarge the partition to 200G, you must extend the PV to match.
A VG isn't a single thing, it's a collection of things. Extending it means to
add more PVs, reducing it means to take PVs out of the VG. Hopefully you will
always remember to migrate the data off a PV before removing it from a VG :-)
Extend/Reduce an LV means to make the device larger/smaller. It is exactly the
same thing as changing a partition size using fdisk. Obviously, you need to
tweak the filesystem at the same time
So, when I get me a new drive, I use pvcreate to get it ready for LVM,
then use vgextend to add it to the VG, then it is available for whatever
LV I want to extend or to make a new LV?
I think I am catching on here. It was just difficult for me to grasp
how things are layered for some reason. Some of the pictures I found
helped a good bit tho. Just helped me picture what the commands are
doing exactly.
I did learn the hard way to resize the file system tho. I forgot that
earlier. Sort of had me scratching my head for a bit. lol
Dale
:-) :-)
