Re: Increase FreeBSD NFSv4 nfsd buffer size? Re: Increase default NFSv4 server size "max_block_size" to 4MB

Rick Macklem <[email protected]> Thu, 14 May 2026 16:36:18 -0700

Newsgroups	gmane.os.freebsd.devel.hackers
Message-ID	<CAM5tNy77YFyfBfydG_NVyT0KT1WX7+bFL1Bm-tdnpsDe=7sw=g@mail.gmail.com>

On Thu, May 14, 2026 at 4:26 PM vermaden <[email protected]> wrote:
>
> > ps: I'll ask over on [email protected] to see if they
> >       think setting to a larger value to make nfs_server_maxio
> >       work is ok with them.
> >
> > rick
>
> I mean ... the script can check if the 'kern.ipc.maxsockbuf' is already 4x'nfs_server_maxio' value or larger.
>
> If 'kern.ipc.maxsockbuf' is larger then needed - do not touch it.
>
> If 'kern.ipc.maxsockbuf' is too small for required 'nfs_server_maxio' value - then set it as 4x'nfs_server_maxio' value.
>
> I doubt this way it will hurt anyone.
We'll see what the transport folk say. They set the default lower for
some reason, I'd assume. It's how much can sit in a socket's recv
queue and I'd guess that might affect things like the recv window
size for TCP,  etc.

rick


>
> Regards,
> vermaden