add swap

pgup12

　　借的



#!/bin/bash
#########################################
#Function:    add a new swap partition
#Usage:       bash add_swap.sh
#Author:      Customer service department
#Company:     Alibaba Cloud Computing
#Version:     2.1
#########################################
check_os_release()
{
while true
do
if cat /proc/version | grep redhat >/dev/null 2>&1
then
os_release=redhat
echo "$os_release"
break
fi
if cat /proc/version | grep centos >/dev/null 2>&1
then
os_release=centos
echo "$os_release"
break
fi
if cat /proc/version | grep ubuntu >/dev/null 2>&1
then
os_release=ubuntu
echo "$os_release"
break
fi
if cat /proc/version | grep -i debian >/dev/null 2>&1
then
os_release=debian
echo "$os_release"
break
fi
break
done
}
check_memory_and_swap()
{
mem_count=$(free -m|grep Mem|awk '{print $2}')
swap_count=$(free -m|grep Swap|awk '{print $2}')
if [ "$mem_count" -ge 15000 ]  && [ "$mem_count" -le 32768 ]
then
if [ "$swap_count" -ge 8000 ]
then
echo -e "\033[1;40;31mYour swap is already enough.Do not need to add swap.Script will exit.\n\033[0m"
rm -rf $LOCKfile
exit 1
elif [ "$swap_count" -ne 0 ]
then
echo -e "\033[40;32mYour swap is not enough,need to add swap.\n\033[40;37m"
remove_old_swap
create_swap 8192
else
echo -e "\033[40;32mYour swap is not enough,need to add swap.\n\033[40;37m"
create_swap 8192
fi
elif [ "$mem_count" -ge 3900 ] && [ "$mem_count" -lt 15000 ]
then
if [ "$swap_count" -ge 3900 ]
then
echo -e "\033[1;40;31mYour swap is already enough.Do not need to add swap.Script will exit.\n\033[0m"
rm -rf $LOCKfile
exit 1
elif [ "$swap_count" -ne 0 ]
then
echo -e "\033[40;32mYour swap is not enough,need to add swap.\n\033[40;37m"
remove_old_swap
create_swap 4096
else
echo -e "\033[40;32mYour swap is not enough,need to add swap.\n\033[40;37m"
create_swap 4096
fi
else
if [ "$swap_count" -ge 2000 ]
then
echo -e "\033[1;40;31mYour swap is already enough.Do not need to add swap.Script will exit.\n\033[0m"
rm -rf $LOCKfile
exit 1
elif [ "$swap_count" -ne 0 ]
then
echo -e "\033[40;32mYour swap is not enough,need to add swap.\n\033[40;37m"
remove_old_swap
create_swap 2048
else
echo -e "\033[40;32mYour swap is not enough,need to add swap.\n\033[40;37m"
create_swap 2048
fi
fi
}
create_swap()
{
root_disk_size=$(df -m|grep -w "/"|awk '{print $4}')
if [ "$1" -gt "$((root_disk_size-1024))" ]
then
echo -e "\033[1;40;31mThe root disk partition has no space for $1M swap file.Script will exit.\n\033[0m"
rm -rf $LOCKfile
exit 1
fi
if [ ! -e $swapfile ]
then
dd if=/dev/zero of=$swapfile bs=1M count=$1
/sbin/mkswap $swapfile
/sbin/swapon $swapfile
/sbin/swapon -s
echo -e "\033[40;32mStep 3.Add swap partition successful.\n\033[40;37m"
else
echo -e "\033[1;40;31mThe /var/swap_file already exists.Will exit.\n\033[0m"
rm -rf $LOCKfile
exit 1
fi
}
remove_old_swap()
{
old_swap_file=$(grep swap $fstab|grep -v "#"|awk '{print $1}')
swapoff $old_swap_file
cp -f $fstab ${fstab}_bak
sed -i '/swap/d' $fstab
}
config_rhel_fstab()
{
if ! grep $swapfile $fstab >/dev/null 2>&1
then
echo -e "\033[40;32mBegin to modify $fstab.\n\033[40;37m"
echo "$swapfile swap swap defaults 0 0" >>$fstab
else
echo -e "\033[1;40;31m/etc/fstab is already configured.\n\033[0m"
rm -rf $LOCKfile
exit 1
fi
}
config_debian_fstab()
{
if ! grep $swapfile $fstab >/dev/null 2>&1
then
echo -e "\033[40;32mBegin to modify $fstab.\n\033[40;37m"
echo "$swapfile none swap sw 0 0" >>$fstab
else
echo -e "\033[1;40;31m/etc/fstab is already configured.\n\033[0m"
rm -rf $LOCKfile
exit 1
fi
}
##########start######################
#check lock file ,one time only let the script run one time
LOCKfile=/tmp/.$(basename $0)
if [ -f "$LOCKfile" ]
then
echo -e "\033[1;40;31mThe script is already exist,please next time to run this script.\n\033[0m"
exit
else
echo -e "\033[40;32mStep 1.No lock file,begin to create lock file and continue.\n\033[40;37m"
touch $LOCKfile
fi
#check user
if [ $(id -u) != "0" ]
then
echo -e "\033[1;40;31mError: You must be root to run this script, please use root to install this script.\n\033[0m"
rm -rf $LOCKfile
exit 1
fi
os_release=$(check_os_release)
if [ "X$os_release" == "X" ]
then
echo -e "\033[1;40;31mThe OS does not identify,So this script is not executede.\n\033[0m"
rm -rf $LOCKfile
exit 0
else
echo -e "\033[40;32mStep 2.Check this OS type.\n\033[40;37m"
echo -e "\033[40;32mThis OS is $os_release.\n\033[40;37m"
fi
swapfile=/var/swap_file
fstab=/etc/fstab
echo -e "\033[40;32mStep 3.Check the memory and swap.\n\033[40;37m"
check_memory_and_swap
echo -e "\033[40;32mStep 4.Begin to modify $fstab.\n\033[40;37m"
case "$os_release" in
redhat|centos)
config_rhel_fstab
;;
ubuntu|debian)
config_debian_fstab
;;
esac
free -m
echo -e "\033[40;32mAll the operations were completed.\n\033[40;37m"
rm -rf $LOCKfile