[CentOS] resize LVM (ext3)

Hello guys,

my scenario is following


   1. I have LVM group named "system"
   2. I have a logical volumes
      - system/root , ext3 mounted as / (20GB)
      - system/swap, swap
      - system/home, ext3 mounted as /home (431GB)

I need to shrink system/home to 80GB (currently there is 57GB used) and use
free space to create another logical volumes.

My scenario is


   1. reduce ext3 fs size to 80GB by using resize2s
   2. reduce system/home size by using lvreduce
   3. create another logical volumes

Questions


   1. How can i be sure that i will shrink ext3 to exact size 80GB and that
   the same will lvreduce do? I do not want to cut from ext3 filesystem if i
   will reduce logical volume too much
   2. Can you please send me commands to achieve 1) and 2) part of my
   scenario?
   3. Or can i just use lvreduce and my ext3 will shrink automatically?
   4. Do i need to umount system/home when resizing?

Thanks in advance!

David
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.centos.org/pipermail/centos/attachments/20081029/85a7d501/attachment.html>