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 Copy linkLink copied to clipboard!
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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
# swapoff -v /dev/VolGroup00/LogVol01
Copy to Clipboard Copied! Toggle word wrap Toggle overflow - Reduce the LVM2 logical volume by 512 MB:
lvreduce /dev/VolGroup00/LogVol01 -L -512M
# lvreduce /dev/VolGroup00/LogVol01 -L -512M
Copy to Clipboard Copied! Toggle word wrap Toggle overflow - Format the new swap space:
mkswap /dev/VolGroup00/LogVol01
# mkswap /dev/VolGroup00/LogVol01
Copy to Clipboard Copied! Toggle word wrap Toggle overflow - Activate swap on the logical volume:
swapon -v /dev/VolGroup00/LogVol01
# swapon -v /dev/VolGroup00/LogVol01
Copy to Clipboard Copied! Toggle word wrap Toggle overflow - To test if the swap logical volume was successfully reduced, inspect active swap space:
cat /proc/swaps free -h
$ cat /proc/swaps $ free -h
Copy to Clipboard Copied! Toggle word wrap Toggle overflow
15.2.2. Removing an LVM2 Logical Volume for Swap Copy linkLink copied to clipboard!
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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
# swapoff -v /dev/VolGroup00/LogVol02
Copy to Clipboard Copied! Toggle word wrap Toggle overflow - Remove the LVM2 logical volume:
lvremove /dev/VolGroup00/LogVol02
# lvremove /dev/VolGroup00/LogVol02
Copy to Clipboard Copied! Toggle word wrap Toggle overflow - Remove the following associated entry from the
/etc/fstab
file:/dev/VolGroup00/LogVol02 swap swap defaults 0 0
/dev/VolGroup00/LogVol02 swap swap defaults 0 0
Copy to Clipboard Copied! Toggle word wrap Toggle overflow - Regenerate mount units so that your system registers the new configuration:
systemctl daemon-reload
# systemctl daemon-reload
Copy to Clipboard Copied! Toggle word wrap Toggle overflow - Remove all references to the removed swap storage from the
/etc/default/grub
file:vi /etc/default/grub
# vi /etc/default/grub
Copy to Clipboard Copied! Toggle word wrap Toggle overflow - Rebuild the grub configuration:
- on BIOS-based machines, run:
grub2-mkconfig -o /boot/grub2/grub.cfg
# grub2-mkconfig -o /boot/grub2/grub.cfg
Copy to Clipboard Copied! Toggle word wrap Toggle overflow - on UEFI-based machines, run:
grub2-mkconfig -o /boot/efi/EFI/redhat/grub.cfg
# grub2-mkconfig -o /boot/efi/EFI/redhat/grub.cfg
Copy to Clipboard Copied! Toggle word wrap Toggle overflow
- To test if the logical volume was successfully removed, inspect active swap space:
cat /proc/swaps free -h
$ cat /proc/swaps $ free -h
Copy to Clipboard Copied! Toggle word wrap Toggle overflow
15.2.3. Removing a Swap File Copy linkLink copied to clipboard!
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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
/swapfile
is the swap file):swapoff -v /swapfile
# swapoff -v /swapfile
Copy to Clipboard Copied! Toggle word wrap Toggle overflow - Remove its entry from the
/etc/fstab
file. - Regenerate mount units so that your system registers the new configuration:
systemctl daemon-reload
# systemctl daemon-reload
Copy to Clipboard Copied! Toggle word wrap Toggle overflow - Remove the actual file:
rm /swapfile
# rm /swapfile
Copy to Clipboard Copied! Toggle word wrap Toggle overflow