15.2. Removing Swap Space
Sometimes it can be prudent to reduce swap space after installation. For example, you have 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.
15.2.1. 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 15.3. Reducing an LVM2 Swap Logical Volume
- Disable swapping for the associated logical volume:
#
swapoff -v /dev/VolGroup00/LogVol01 - Reduce the LVM2 logical volume by 512 MB:
#
lvreduce /dev/VolGroup00/LogVol01 -L -512M - Format the new swap space:
#
mkswap /dev/VolGroup00/LogVol01 - Activate swap on the logical volume:
#
swapon -v /dev/VolGroup00/LogVol01 - To test if the swap logical volume was successfully reduced, inspect active swap space:
$
cat /proc/swaps$free -h
15.2.2. 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 15.4. Remove a Swap Volume Group
- Disable swapping for the associated logical volume:
#swapoff -v /dev/VolGroup00/LogVol02 - Remove the LVM2 logical volume:
#lvremove /dev/VolGroup00/LogVol02 - Remove the following associated entry from the
/etc/fstabfile:/dev/VolGroup00/LogVol02 swap swap defaults 0 0
- Regenerate mount units so that your system registers the new configuration:
#systemctl daemon-reload - Remove all references to the removed swap storage from the
/etc/default/grubfile:#vi /etc/default/grub - Rebuild the grub configuration:
- on BIOS-based machines, run:
#grub2-mkconfig -o /boot/grub2/grub.cfg - on UEFI-based machines, run:
#grub2-mkconfig -o /boot/efi/EFI/redhat/grub.cfg
- To test if the logical volume was successfully removed, inspect active swap space:
$
cat /proc/swaps$free -h
15.2.3. Removing a Swap File
To remove a swap file:
Procedure 15.5. Remove a Swap File
- At a shell prompt, execute the following command to disable the swap file (where
/swapfileis the swap file):#
swapoff -v /swapfile - Remove its entry from the
/etc/fstabfile. - Regenerate mount units so that your system registers the new configuration:
#systemctl daemon-reload - Remove the actual file:
#
rm /swapfile
