I did next operation for nfs adjusting.
On server 192.168.0.1 in file /etc/exports made the record
/obmin2 192.168.0.20(rw)
then run /usr/sbin/exportfs -r
and got
/obmin2 192.168.0.20(rw,sync,wdelay,hide,secure,root_squash,not_all_squash,subtree_check,secure_locks,mappin g=identity,annonuid=-2) in /var/libs/nfs/xtab
Then started nfs: /etc/rc.d/init.d/nfs start
On client 192.168.0.20 in /etc/fstab:
192.168.0.1:/obmin2 /obmin2 nfs rw 0 0
And run mount -t nfs 192.168.0.1:/obmin2 /obmin2
Then got mount: RPC: remote system error - Connection failed.
Why?

Do you have portmap running on the client side?

No