[NTLUG:Discuss] Resizing Linux partitions

[Robert Citek]

On 06/18/2007 02:21 PM, Robert Pearson wrote:
> Thanks. This is great.
> It cleared up a lot of confusion for me.
> Now I need some help understanding the Volume Manager (LVM),
> partitions and file systems.
> The goal is to be able to resize (shrink or grow) using the Volume Manager.
> The reading indicates this pretty much makes you file system and
> partition independent.

Sort of.  For example, you can't resize a partition if it's in use, i.e.
part of a volume group, IIRC.

> So far I have destroyed everything I have tried using all three of these.
> All help is appreciated.

It's been a while since I've worked with LVM, but the concept is
similar.  It helps me to think in terms of containers.  Disks contain
partitions.  Partitions contain filesystems.  Filesystems contain files.
 Files contain data.  But all of those containers are organizational
conveniences.  In the end, it's all data on a disk.  That's why you can
create images of disks, partitions, and filesystems.

With LVM, you put all your real block devices (e.g. partitions, drives,
loopback files, etc.) into a pool (a volume group).  From this pool you
 create a virtual partition (a logical volume).  You then put a file
system in the virtual partition.

BTW, I recommend playing with LVM (or RAID or anything involving
partitions) on a second internal drive, an external drive, or with
loop-backed files.  In my experience, it just simplifies the learning
process.

Regards,
- Robert