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:
