$ cat /etc/redhat-release
CentOS Linux release 8.3.2011
$ uname -a
Linux server 4.18.0-240.1.1.el8_3.x86_64 #1 SMP Thu Nov 19 17:20:08 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux
sudo systemctl disable --now firewalld
sudo sed -i s/^SELINUX=.*$/SELINUX=disabled/ /etc/selinux/config
sudo dnf install nfs-utils -y
sudo systemctl enable --now nfs-server
$ cat /proc/fs/nfsd/versions
-2 +3 +4 +4.1 +4.2
sudo mkdir /mnt/nfs_share -p
$ sudo chown nobody.nobody /mnt/nfs_share
$ ls -ld /mnt/nfs_share
drwxr-xr-x 2 nobody nobody 6 Aug 11 04:21 /mnt/nfs_share
$ sudo vi /etc/exports
/mnt/nfs_share 192.168.2.21(rw,sync,no_all_squash,root_squash)
sudo systemctl restart nfs-server
$ showmount -e 192.168.2.20
Export list for 192.168.2.20:
/mnt/nfs_share 192.168.2.21
$ sudo mount -t nfs 192.168.2.20:/mnt/nfs_share /mnt
$ df -h | grep /mnt/
192.168.2.20:/mnt/nfs_share 10G 3.4G 6.7G 34% /mnt
$ sudo touch /mnt/test.txt
$ ls -l /mnt/test.txt
-rw-r--r-- 1 nobody nobody 0 Aug 11 04:34 /mnt/test.txt
$ sudo vi /etc/fstab
192.168.2.20:/mnt/nfs_share /mnt nfs defaults,timeo=900 0 0
$ sudo shutdown -r now
$ df -h | grep /mnt/
192.168.2.20:/mnt/nfs_share 10G 3.4G 6.7G 34% /mnt
$ sudo umount /mnt/
$ df -h | grep /mnt/