Network Design are an important consideration for NFS. Note the followings:

1. If possible, dedicate the network to isolate the NFS Traffic.
2. Trunking of multiple network to imporive network connections (Will write a blog entry later)
3. If you have budget, you can consider a high-quality NAS which uses NFS accelerator components such as nonvolative RAM to commit NFS write operation as soon as possible which equivalent up to equivalent of async with reliability.