Snapshot/Rollback using LVM/EVMS

["pavel.orehov@gmail.com" <pavel.orehov@gmail.com>]

Hi,

I am using debian linux and i want to make a system snapshot using LVM
or EVMS.
Now i am having running system with one partition (/dev/hda1 of 30GB,
~7GB used) and i can't modify or delete existing data.
I want to take the snapshot (one or more) in some point, save it
locally and rollback if needed.

My question is what better to use LVM or EVMS?

What exact steps to make system snapshot and rollback with both of
them?

Note: I have the User Guide of both of them, but it a little confusing.

Thanks,
Pavel