=> vgdisplay                                                                                                                                               [1]
  --- Volume group ---
  VG Name               VolGroup00
  System ID             
  Format                lvm2
  Metadata Areas        2
  Metadata Sequence No  10
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                2
  Open LV               1
  Max PV                0
  Cur PV                2
  Act PV                2
  VG Size               150.66 GB
  PE Size               32.00 MB
  Total PE              4821
  Alloc PE / Size       3644 / 113.88 GB
  Free  PE / Size       1177 / 36.78 GB
  VG UUID               J3nU9B-fqX2-dGep-L54d-rTst-rXtI-JDRSjl

=> swapoff -a                                
=> free -m
             total       used       free     shared    buffers     cached
Mem:          2533       2439         93          0         98        984
-/+ buffers/cache:       1357       1175
Swap:            0          0          0
=> lvreduce -L -500M /dev/VolGroup00/LogVol01
  Rounding up size to full physical extent 480.00 MB
  WARNING: Reducing active logical volume to 544.00 MB
  THIS MAY DESTROY YOUR DATA (filesystem etc.)
Do you really want to reduce LogVol01? [y/n]: y
  Reducing logical volume LogVol01 to 544.00 MB
  Logical volume LogVol01 successfully resized
=> mkswap /dev/VolGroup00/LogVol01 
Setting up swapspace version 1, size = 570421 kB
=> swapon -a                                 
=> free -m
             total       used       free     shared    buffers     cached
Mem:          2533       2433         99          0         97        978
-/+ buffers/cache:       1357       1175
Swap:          543          0        543
=> vgdisplay 
  --- Volume group ---
  VG Name               VolGroup00
  System ID             
  Format                lvm2
  Metadata Areas        2
  Metadata Sequence No  12
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                2
  Open LV               2
  Max PV                0
  Cur PV                2
  Act PV                2
  VG Size               150.66 GB
  PE Size               32.00 MB
  Total PE              4821
  Alloc PE / Size       3645 / 113.91 GB
  Free  PE / Size       1176 / 36.75 GB
  VG UUID               J3nU9B-fqX2-dGep-L54d-rTst-rXtI-JDRSjl