Update: 2017-01-06
Warn 1: for non-English, use samba/sshfs instead. unless win has NFS v4 or above which can solve non-UTF8 problems.
Warn 2: svchost consumes 1.5GB ram, don't know why.

See Also Links
SSHFS/SFTP
CIFS/SMB/Samba

OBS

Combining simlink (ln -s) with NFS may cause weird file path problems. We tried to have a link at NFS to Dropbox in nfs, also tried to have a link at home to mount point at /mnt. Both caused some minor path and file issues, but no series problems.

UBUNTU SERVER

sudo -s

apt-get install nfs-kernel-server && vim /etc/exports

<absolutePathFolderToShare> 192.168.1.0/24(rw,async,no_subtree_check,no_root_squash)

OBS: not 192.168.1.*
To run:

/usr/sbin/exportfs -a
service nfs-kernel-server restart
service nfs-kernel-server status

To change UID/GID when exporting, use all_squash,anonuid=xxx,anongid=yyy. [serverfault]

To use usernames instead of IDs, use echo N > /sys/module/nfs/parameters/nfs4_disable_idmapping. [serverfault]

UBUNTU AS A CLIENT

temporarily

sudo -s

apt-get -q install -y nfs-common && mkdir -p /mnt/nfsMountPoint
mount -t nfs serverIpOrDomain:/absolute/path /mnt/nfsMountPoint

1. Option -o nolock can be used for mount, which disables file locking. This setting is occasionally required when connecting to older NFS servers. ref.
2. Use umount to unmount.

permanently

mkdir -p /local/nfsMountPoint
echo 'nfsServerOrIp:/absolute/path/    /local/nfsMountPoint   nfs    defaults  0  0' >> /etc/fstab

defaults could be replaced by some of auto,nofail,noatime,nolock,intr,tcp,actimeo=1800. [ ref1, ref2 ]

For Synology NAS, see the official tutorial.

WINDOWS 7 AS A CLIENT

set permission

To have write permission, we need to set userId:groupId the same as server side.
Check server's /etc/passwd for server side folder's owner, it is usually 1000:1000 (in decimal base) for the 1st non-root ubuntu user.
Modify window regedit (the win sys service should be started once to have this reg key):

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\ClientForNFS\CurrentVersion\Default]
"AnonymousUid"=dword:000003e8
"AnonymousGid"=dword:000003e8

(if the .reg is used after enabling win NFS feature, restart the windows service or reboot, then remount.)

enable

Enable the windows feature "Client for NFS". ref

mount

Run in cmd (NOT powerShell !!!)

mount <serverIpOrDomain>:<absolutePathFolderToShare> Z:
# e.g.:
mount google.com:/home/abc/theFolder Z:

To unmount: use umount, (ref)
Note: Persistent NFS mount (after reboot) is not an option with NFS. Also this scenario is not recommended and does not guarantee a sure shot solution (ref).

ref

encoding problem (only in win???)

Description: files created in win with non-ASCII chars will become question marks '?' in linux, also when read again in win.
Solution: no way to solve, unless NFS v4. see super.user

To check nfs versions on server: nfsstat
To check on linux clinet: mount -v; nfsstat -m ref
To check on win client: ？？？

RESTART

service nfs-kernel-server restart

RESULTS

The right side drive (Z:) is NFS, which shows wrong space usage, and display speed is much slower than SMB (left side, Y:) when mounted in windows. For space usage, by default, ext2/3/4 filesystems reserve 5% of the space to be useable only by root, see ref.