Migrated a lvm space to a swap memory on CentOS 7
1. lvmdisplay to get lv path 2. lvreduce -L -8G /dev/centos /dev/centos/sharedisk 3. lvcreate -L 8G -n lvswap centos # centos is VG Name 4. mkswap /dev/centos/lvswap 5. swapon -a