14.2. 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.

14.2.1. Reducing Swap on an LVM2 Logical Volume

To reduce an LVM2 swap logical volume (assuming /dev/VolGroup00/LogVol01 is the volume you want to reduce):

Procedure 14.3. Reducing an LVM2 Swap Logical Volume

  1. Disable swapping for the associated logical volume:
    # swapoff -v /dev/VolGroup00/LogVol01
  2. Reduce the LVM2 logical volume by 512 MB:
    # lvreduce /dev/VolGroup00/LogVol01 -L -512M
  3. Format the new swap space:
    # mkswap /dev/VolGroup00/LogVol01
  4. Enable the extended logical volume:
    # swapon -v /dev/VolGroup00/LogVol01
To test if the swap's logical volume size was successfully reduced, use cat /proc/swaps or free to inspect the swap space.

14.2.2. Removing an LVM2 Logical Volume for Swap

To remove a swap volume group (assuming /dev/VolGroup00/LogVol02 is the swap volume you want to remove):

Procedure 14.4. Remove a Swap Volume Group

  1. Disable swapping for the associated logical volume:
    # swapoff -v /dev/VolGroup00/LogVol02
  2. Remove the LVM2 logical volume of size 512 MB:
    # lvremove /dev/VolGroup00/LogVol02
  3. Remove the following entry from the /etc/fstab file:
    /dev/VolGroup00/LogVol02 swap swap defaults 0 0
To test if the logical volume size was successfully removed, use cat /proc/swaps or free to inspect the swap space.

14.2.3. Removing a Swap File

To remove a swap file:

Procedure 14.5. Remove a Swap File

  1. At a shell prompt, execute the following command to disable the swap file (where /swapfile is the swap file):
    # swapoff -v /swapfile
  2. Remove its entry from the /etc/fstab file.
  3. Remove the actual file:
    # rm /swapfile