Adding SWAP space on Oracle Linux 8.x using swap file

This article will guide you how you can add the swap space on Oracle Linux 8.x operating system. In this method we will use the swap file for adding it to the swap memory. Currently allocated swap memory – 8 GB New swap memory to be added – 32 GB

[root@racnode1 ~]# df -h
Filesystem              Size  Used Avail Use% Mounted on
devtmpfs                756G     0  756G   0% /dev
tmpfs                   756G  4.0K  756G   1% /dev/shm
tmpfs                   756G   27M  756G   1% /run
tmpfs                   756G     0  756G   0% /sys/fs/cgroup
/dev/mapper/ol-root     100G  2.8G   98G   3% /
/dev/sda2               945M  223M  658M  26% /boot
/dev/sda1               488M  5.2M  483M   2% /boot/efi
/dev/mapper/ol-oracle   500G  3.6G  497G   1% /oracle
/dev/mapper/ol-ortrace  500G  3.6G  497G   1% /oracle/trace
tmpfs                   152G     0  152G   0% /run/user/0
[root@racnode1 ~]#

Create swap file with 32GB size:

[root@racnode1 ~]# dd if=/dev/zero of=/root/newswap bs=1M count=32768
32768+0 records in
32768+0 records out
34359738368 bytes (34 GB, 32 GiB) copied, 10.0707 s, 3.4 GB/s
[root@racnode1 ~]#

Verify the created swap file:

[root@racnode1 ~]# ls /root/newswap
/root/newswap
[root@racnode1 ~]# ls -l /root/newswap
-rw-r--r--. 1 root root 34359738368 Mar 15 13:00 /root/newswap

Enable swap file properties on newly created file:

[root@racnode1 ~]# chmod 600 /root/newswap
[root@racnode1 ~]# mkswap /root/newswap
Setting up swapspace version 1, size = 32 GiB (34359734272 bytes)
no label, UUID=24da1634-9c5c-41df-a9fb-5e53ff002d49
[root@racnode1 ~]#

Add the new swapfile to /etc/fstab for boot persistency:

[root@racnode1 ~]# vi /etc/fstab

Verify the newly added swap space:

[root@racnode1 ~]# swapon -sq
Filename                                Type            Size    Used    Priority
/dev/dm-1                               partition       8388604 0       -2
/root/newswap                           file            33554428        0       -3
[root@racnode1 ~]# swapon -s
Filename                                Type            Size    Used    Priority
/dev/dm-1                               partition       8388604 0       -2
/root/newswap                           file            33554428        0       -3
[root@racnode1 ~]# free
              total        used        free      shared  buff/cache   available
Mem:     1584370860     1683740  1548134020       26752    34553100  1575477784
Swap:      41943032           0    41943032
[root@racnode1 ~]#

Thanks for reading 😊 Regards, ZAHEER