NFS share problems - RPC: fragment too large: xxxxx

We have a virtual server with an NFS share that is written to by other servers. Today the NFS share became inaccessible. The syslog was full off messages like this:

RPC: fragment too large: 311176

I've seached on google but can't find much information about this. Could someone explain what this means?

A rpc message (and NFS is rpc based service) can be split into multiple frames (chunks). Any RPC server has a limit on frame size as well as a limit on message size. "RPC: fragment too large: " indicates that NFS server got a rpc frame which is bigger than max allowed size. This message can point to a bug in the client code, server code or network issues. Port scans can trigger such situation as well.