add swap logic

swap.sh

umount /data
mkdir /cy
cp /data/* /cy
#e2fsck -fy  /dev/mapper/centos-data
lvreduce -L -10G /dev/mapper/centos-data
#resize2fs /dev/mapper/centos-data
#mke2fs /dev/mapper/centos-data
#xfs_repair /dev/mapper/centos-data
#xfs_growfs /dev/mapper/centos-data
mkfs.xfs -f /dev/mapper/centos-data
mount /data
cp /cy/* /data
rm -rf /cy
fdisk /dev/sdb

lvcreate -L 9G -n swap centos
 mkfs.xfs -f /dev/mapper/centos-swap
#mount /dev/mapper/centos-swap /swap
#mount /dev/mapper/centos-data /data
#dd if=/dev/mapper/zero of=/data/swap bs=1024 count=8000M
#mkswap /data/swap
#swapon /data/swap
mkswap /dev/mapper/centos-swap
swapon  /dev/mapper/centos-swap
echo "/dev/mapper/centos-swap swap                    swap    defaults        0 0" >> /etc/fstab