NFS Locking Issue

[Michael Collette]

Michel Talon wrote:
>> I guess I'm still just a bit stunned that a bug this obvious not only 
>> found it's way into the STABLE branch, but is still there.  Maybe it's 
>> not as obvious as I think, or not many folks are using it?  All I know 
>> for sure here is that if I had upgraded to 6.1 my network would have 
>> been crippled.
> 
> Strange, since i upgraded to FreeBSD-6.1 and the NFS server to Fedora Core 5,
> my machine, NFS client is happy, and lockd works. It is first time since
> years i have no problem. It certainly did not work with FreeBSD-5 and i still
> have a machine with FreeBSD-6.0 which does not work properly (frequently loses
> the NFS mount, but it gets remounted some times later by amd). Anyways i have
> exactly 0 problem with the 6.1 machine. I could extend that to say that
> everything works very well on that machine, nothing is slow, including disk
> access. This has not always been the case. Stability wise, i have not seen any
> panic, hang or whatever since i have compiled a kernel adapted to my hardware.
> I got a panic with the generic kernel soon after installation, but now
> machine is totally stable.

Based on prior reading about this problem, I'd venture to guess that the 
file locking between FC5 and FreeBSD simply isn't.  See, between just 2 
machines sharing files without rpc.lockd running you won't see a 
problem.  Both the client and the server must not only be running 
rpc.lockd, but they must be able to actually talk to each other.

For a simple 2 machine setup, you don't really need much in the way of 
locking control, as you don't have to deal with multiple requests for 
the same resource.  This is why folks just running the "-L" flag on 
their mount command also aren't having any problems.

To actually see the problem isn't too hard to set up.  Just have 
rpc.lockd, rpc.statd, and rpcbind enabled on both the client and the 
server.  Then just starting trying to transfer a stack of files from one 
to the other.  I found this to be true even trying to go from a 5.4 
server to my 6.1 laptop here.

There was quite a thread on this back in March of this year, along with 
a few PR's that are still opened up.  I'm personally just coming head 
long into all of this.

Later on,
-- 
Michael Collette
IT Manager
TestEquity Inc
Michael.Collette at TestEquity.com