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.
To reduce an LVM2 swap logical volume (assuming
/dev/VolGroup00/LogVol01 is the volume you want
to extend):
Disable swapping for the associated logical volume:
# swapoff -v /dev/VolGroup00/LogVol01 |
Reduce the LVM2 logical volume by 512 MB:
# lvm lvreduce /dev/VolGroup00/LogVol01 -L -512M |
Format the new swap space:
# mkswap /dev/VolGroup00/LogVol01 |
Enable the extended logical volume:
Test that the logical volume has been reduced properly:
The swap logical volume cannot be in use (no system locks or processes
on the volume). The easiest way to achieve this it to boot your system
in rescue mode. Refer to Chapter 5 Basic System Recovery for
instructions on booting into rescue mode. When prompted to mount the
file system, select Skip.
To remove a swap volume group (assuming
/dev/VolGroup00/LogVol02 is the swap volume
you want to remove):
Disable swapping for the associated logical volume:
# swapoff -v /dev/VolGroup00/LogVol02 |
Remove the LVM2 logical volume of size 512 MB:
# lvm lvremove /dev/VolGroup00/LogVol02 |
Remove the following entry from the /etc/fstab file:
/dev/VolGroup00/LogVol02 swap swap defaults 0 0 |
Test that the logical volume has been extended properly:
To remove a swap file:
At a shell prompt as root, execute the following command to
disable the swap file (where /swapfile is the
swap file):
Remove its entry from the /etc/fstab file.
Remove the actual file:
