Re: partition magic-ally

["prash" <iprash@gmail.com>]

hello,
  i installed the partitions using lvm on my home machine which only
has 10 GB.

here is a df -h:

mantra:/home/prash# df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/rootvol-root
                      1.7G  200M  1.4G  13% /
tmpfs                 126M     0  126M   0% /dev/shm
/dev/mapper/rootvol-home
                      2.8G   40M  2.6G   2% /home
/dev/mapper/rootvol-usr
                      1.7G  1.5G   59M  97% /usr
/dev/mapper/rootvol-usr_local
                      2.8G  472M  2.2G  18% /usr/local

---------------

i then realised /usr has no more free space. so, i used a combination
of lvreduce and lvextend to change the sizes a little bit and here is
the output of lvdisplay:

--------------

mantra:/home/prash# lvdisplay
  --- Logical volume ---
  LV Name                /dev/rootvol/root
  VG Name                rootvol
  LV UUID                bgdtx8-x12o-hH3U-0GZY-iWVk-9Z0Z-dE1nUF
  LV Write Access        read/write
  LV Status              available
  # open                 1
  LV Size                1.75 GB
  Current LE             448
  Segments               1
  Allocation             inherit
  Read ahead sectors     0
  Block device           254:0

  --- Logical volume ---
  LV Name                /dev/rootvol/usr
  VG Name                rootvol
  LV UUID                a0j5aF-ej5f-fq9y-j32N-TA1I-aLmG-zAR5xB
  LV Write Access        read/write
  LV Status              available
  # open                 1
  LV Size                2.75 GB
  Current LE             704
  Segments               2
  Allocation             inherit
  Read ahead sectors     0
  Block device           254:1

  --- Logical volume ---
  LV Name                /dev/rootvol/usr_local
  VG Name                rootvol
  LV UUID                wO8fh0-H7Wc-e1Nf-Ek6M-Ek51-r1As-ifZmhj
  LV Write Access        read/write
  LV Status              available
  # open                 1
  LV Size                2.75 GB
  Current LE             704
  Segments               1
  Allocation             inherit
  Read ahead sectors     0
  Block device           254:2

  --- Logical volume ---
  LV Name                /dev/rootvol/home
  VG Name                rootvol
  LV UUID                JjAi4a-NqqR-8n8G-eaHU-eVQV-8sIi-hYsD0l
  LV Write Access        read/write
  LV Status              available
  # open                 1
  LV Size                1.73 GB
  Current LE             444
  Segments               2
  Allocation             inherit
  Read ahead sectors     0
  Block device           254:3

  --- Logical volume ---
  LV Name                /dev/rootvol/swap
  VG Name                rootvol
  LV UUID                ShUUbV-q6Im-fVIj-2EPF-w1jz-DUQp-CWrfDF
  LV Write Access        read/write
  LV Status              available
  # open                 1
  LV Size                556.00 MB
  Current LE             139
  Segments               1
  Allocation             inherit
  Read ahead sectors     0
  Block device           254:4

------------------------


as can be seen, it says that /dev/rootvol/usr (which is mapped to /usr)
has 2.75G now and /home has reduced to 1.73G.
my problem is that df -h is still showing the old status (/usr is still
1.7G and /home is still 2.8G)! no change at all!
how come lvdisplay is showing the changes in the logical volumes, but
df is not showing them?
i am assuming df is the right representation of my system, so what's up
with lvm?

any help will be much appreciated,
-prash.