To use dCore as an NFS server, import the following packages:

nfs-kernel-server
filesystems-$KERNELVERSION

KERNELVERSION can be found with the below command:

uname -r

Use sce-load to load those packages, and then create an entry in
/etc/exports like below if you want to share /mnt/sda1 and your
network is 192.168.0.*:

/mnt/sda1     192.168.0.*(fsid=0,rw,sync,no_subtree_check)

Then issue the following commands:

sudo /etc/init.d/rpcbind start
sudo /etc/init.d/nfs-kernel-server start

On the client, you have the choice of using Busybox mount to mount the 
NFS share, or import the nfs-common package and use the regular mount
command which may have more options.  If using Busybox, do the following
on the client:

sudo mkdir /tmp/sda1
sudo busybox mount -o nolock 192.168.0.7:/mnt/sda1 /tmp/sda1

This is if your server address is 192.168.0.7, and the NFS share is 
/mnt/sda1.  Alternately, the nfs-common package can be imported on 
the client and used.  

sce-import nfs-common
sce-load nfs-common
sudo /etc/init.d/rpcbind start

Then the regular mount command can be used to mount NFS shares.

sudo mount 192.168.0.7:/mnt/sda1 /tmp/sda1

On the client, if you want a user to be able to mount the NFS share
then enter the below line in /etc/fstab:

192.168.0.7:/mnt/sda1 /tmp/sda1 nfs rw,noauto,user 0 0

Then mount the NFS share with the appropriate below command:

busybox mount -o nolock /tmp/sda1
mount /tmp/sda1