For anybody who try to install simplest home NFS on 2 computers with RedHat(7.3;8.0):
Wihout details, but only important things.
This way - is not best way, but for fast installation of simple home network.

0)Check your NFS deamons work(how to do it - look another threads)

1) turn off DEFAULT firewalls on both computers,
there are number ways how to do it, but simplest one(not best) - remove packages:
rpm -e lokkit
rpm -e ipchains

2)reboot(remember windows)

3)write in /etc/export on server side:
/exportFolder 192.168.0.2/255.255.255.0(rw,sync)
Parameters:
192.168.0.2/255.255.255.0 - client IP with subnet mask

/exportFolder - path to exported directory on server
side

4)Open terminal and execute : exportfs -rv

5)on client's /etc/fstab write:
servername.serverdomain:/exportFolder /importFolder nfs rsize=8192,wsize=8192,user

Paremeters:
/importFolder - directory on client side:
You must create this directory before.
6)In your /etc/hosts.allow on server side:
write :
portmap: 192.168.0.2/255.255.255.0
Parameters:192.168.0.2/255.255.255.0 - IP/subNetMask
of your client
7)In servers /etc/hosts.deny
write:
portmap: ALL

8)restart client or mount by fingers(how to do it look another threads)


Gurus will find here 100 security and others faults, but
this message only for simplest and easy NFS.