Can UDP be used with NFSv2 ?

[Mel Burslan]

I have been asked this question by a colleague of mine and befuddled. Does anyone use NFS2 anymore ? More importantly does anyone know the answer to this ?
Also any other constraints that one should be aware of like client's NFS version or any other software running on either side ?
Thanks for the help in advance.

[Stuart Browne]

Given that NFS is a tcp based protocol, which uses RPC Portmap for it's port handling, I'd say flat out that UDP is not used anywhere in the conversation.

Given the nature of the data transferred, i.e. files which require integrity, TCP is the only choice. UDP is not guaranteed delivery, no error checking and not good for sustained data streams.

TCP has all of this stuff built in.

[Steven E. Protter · Accepted solution]

On Unix NFS v2's problem was that it was using UDP. Going to v3 and tcp was a major improvement in performance and reliablity.

I honestly don't know about Linux, but that applies to NFS in general.

You probably can do what you state. I don't know why though.

SEP

[Claudio Cilloni]

mmmmh... in my home LAN (rh73 <-> rh9) nfs works with UDP... I configured it with almost all the default settings. I don't know if it can be configured to use TCP.Once I read something about nfs uses UDP because over a LAN it is enoughreliable and it gives less overload than TCP...hthClaudio

[Huc_1]

To make matters worst this is what I found edit/reading my /usr/src/linux/.config

# Network File Systems
#
CONFIG_CODA_FS=m
CONFIG_INTERMEZZO_FS=m
CONFIG_NFS_FS=m
CONFIG_NFS_V3=y
CONFIG_NFSD=m
CONFIG_NFSD_V3=y
CONFIG_SUNRPC=m
CONFIG_LOCKD=m
CONFIG_LOCKD_V4=y

I do not really now what this means... perhaps if not yes at CONFIG_NFS_V3=y then
it use V2 per default ? just guessing.

J-P