LVM: Reduce SWAP size by removing a Logical Volume -

LVM: Reduce SWAP size by removing a Logical Volume

# Tested on RHEL 5, 6 & 7

# Check current swap volume(s) and its size

root@<server>:/#> cat /etc/fstab | grep swap
/dev/rvg/swaplv         swap                    swap    defaults        0 0
/dev/rvg/newswaplv      swap                    swap    defaults        0 0

root@<server>:/#> free -m
             total       used       free     shared    buffers     cached
Mem:         11239        392      10846          0        102        120
-/+ buffers/cache:        169      11069
Swap:        15039          0      15039                                       <----

root@<server>:/#> cat /proc/swaps
Filename                                Type            Size    Used    Priority
/dev/mapper/rvg-swaplv                  partition       14352376        0       -1
/dev/mapper/rvg-newswaplv               partition       1048568 0       -2

# We will reduce swap space by removing /dev/mapper/rvg-newswaplv Logical Volume

# Disable swapping on selected LV

root@<server>:/#> swapoff /dev/rvg/newswaplv

# Check new size and partitions being used by swap

root@<server>:/#> free
             total       used       free     shared    buffers     cached
Mem:      11508864     401412   11107452          0     104992     123432
-/+ buffers/cache:     172988   11335876
Swap:     14352376          0   14352376                                       <----

root@<server>:/#> cat /proc/swaps
Filename                                Type            Size       Used    Priority
/dev/mapper/rvg-swaplv                  partition       14352376        0       -1

# Remove following line from /etc/fstab to prevent system from mounting removed LV

/dev/rvg/newswaplv         swap                    swap    defaults        0 0

# If necessary, completely remove Logical Volume

# root@<server>:/#> lvremove /dev/rvg/newswaplv
# Do you really want to remove active logical volume newswaplv? [y/n]: y
# Logical volume "newswaplv" successfully removed