Add/Increase swap space in Linux

[root@myhost ~]# dd if=/dev/zero of=/swapfile1 bs=1024 count=10485760
10485760+0 records in
10485760+0 records out
10737418240 bytes (11 GB) copied, 110.084 s, 97.5 MB/s
[root@myhost ~]# chown root:root /swapfile1
[root@myhost ~]# chmod 0600 /swapfile1
[root@myhost ~]# mkswap /swapfile1
Setting up swapspace version 1, size = 10485756 KiB
no label, UUID=a7a5c45b-d56a-424f-8c50-41149fdd0935
[root@myhost ~]# swapon /swapfile1
[root@myhost ~]# free -m
              total        used        free      shared  buff/cache   available
Mem:          15456        7999          87         161        7369        7132
Swap:         17919           0       17919
[root@myhost ~]# vi /etc/fstab
add the following line



/swapfile1 none swap sw 0 0

[root@myhost ~]# free -m
              total        used        free      shared  buff/cache   available
Mem:          15456        8573          89         161        6793        6553
Swap:         17919           0       17919