11.3. Removing Swap Space

Sometimes it can be prudent to reduce swap space after installation. For example, say you downgraded the amount of RAM in your system from 1 GB to 512 MB, but there is 2 GB of swap space still assigned. It might be advantageous to reduce the amount of swap space to 1 GB, since the larger 2 GB could be wasting disk space.
You have three options: remove an entire LVM2 logical volume used for swap, remove a swap file, or reduce swap space on an existing LVM2 logical volume.

11.3.1. Reducing Swap on an LVM2 Logical Volume

To reduce an LVM2 swap logical volume (assuming /dev/VolGroup00/LogVol01 is the volume you want to extend):
  1. Disable swapping for the associated logical volume:
     # swapoff -v /dev/VolGroup00/LogVol01 
  2. Reduce the LVM2 logical volume by 512 MB:
     # lvm lvreduce /dev/VolGroup00/LogVol01 -L -512M 
  3. Format the new swap space:
     # mkswap /dev/VolGroup00/LogVol01 
  4. Enable the extended logical volume:
     # swapon -va 
  5. Test that the logical volume has been reduced properly:
     # cat /proc/swaps # free