Re: NFS locking and statd

Bill Hawes (
Mon, 15 Dec 1997 09:39:08 -0500

Olaf Kirch wrote:
> The basic idea of statd is to implement a notification service that tells
> the kernel when the NFS peer reboots. This enables the server to discard
> all locks held by the client (if the client reboots), and the client to
> re-establish all locks with the server (if the server reboots).
> The protocol underlying statd is NSM, the network service monitoring
> protocol. It would have been more appropriately named notification
> protocol, because in fact all it does is send around little messages
> saying 'I have just booted'. In order to avoid being fooled by
> retransmissions of these messages, NSM includes a state number that
> is incremented by 2 each time the host reboots.

Hi Olaf,

Thanks, that gives me a much clearer picture of the lockd-statd
interaction. But it seems to me that if statd is required to use lockd,
it might be better to subsume the operations into the lockd process
rather than having yad. Or would it be possible to make statd optional
for installations that seldom reboot and/or make only light use of

> I'll see what I can do. I had also planned to release some of my
> NFSv3 patches before christmas....

Thanks, this will help get more people involved in testing knfsd.

> As for a statd manpage, you should ask Jeff himself.

Will do.