Re: [BUG?] Maybe NFS bug since 2.6.37 on SPARC64

Chuck Lever
2011-11-04T14:02:23Z

On Nov 4, 2011, at 9:20 AM, Jim Rees wrote:

> As for a fix... we're trying to move away from udp transport anyway. Maybe
> someone should figure out a way to get it to work with tcp? I have zero
> experience with nfs over udp, at least on linux. Just for fun, have you
> tried tcp transport (proto=tcp)?

TCP is a real problem in this environment, because it deals poorly with NIC initialization timing issues. UDP is still the best approach (as long as it is retransmitting appropriately). To support TCP, ultimately what we need to do is to introduce serialization to make the kernel wait for the NIC to become ready before attempting network activity.

> As we move toward nfs4 someone will have to give some thought to nfsroot.
> It's hard to imagine we could put enough nfs4 cruft into the kernel (gssd,
> idmapd) to make it work.

A kernel-level basic id mapper is being considered. That would allow NFSv4 with AUTH_SYS, if we can get the NIC problems squared away.

--
Chuck Lever
chuck[dot]lever[at]oracle[dot]com