From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2FBA5377031 for ; Mon, 30 Mar 2026 18:46:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774896413; cv=none; b=NuAxo6FfLorZK2wznc9aS84nMddlz3bRH3NXyRoXaeqSPZLUyrTLsZJHjGf/5tXo+1jMnGXWqAMerYlMobzl9Lkgu7bofzU55FO5Q93Jv+12zlt3d0n+XJc8agn/g3wlgnI1D4OD1NlUOiXjYZEgZUeqH21bv68RRYsk1uBMMLU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774896413; c=relaxed/simple; bh=ualoCU9xZiTW/5azMt6BlLYYx9lZyL0DJlQD7dTMZQI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=gJYaPNKdVpecHQk5KWPLXAjOT4d2nrCl7H7AiDYYjCpsBa8epwKtBOzC9QSb+T4CTQ5QakV3NtwgW6isetY/9FKNdLxbT6SONgGrk4XPodnAV+K/Gk+3OfxATdAIRcr0SaY8PbRx8S4PONluUAX0W3D7ypeSmIJEkiHkSEJ939s= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Efg8pyHy; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Efg8pyHy" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 955BEC4CEF7; Mon, 30 Mar 2026 18:46:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1774896412; bh=ualoCU9xZiTW/5azMt6BlLYYx9lZyL0DJlQD7dTMZQI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Efg8pyHyrJjzKx1JfO65rRvEbi+18yDM2pSEcGbf24gbPEBmaRhUy4XOnAYpkJ1tz UFccLxvgeQAykim1aqgaFAx98JjkJTseok25y3WOXh4/Fvsj5EfmGk/GdeH1l/QUEL mIZj61Oqx0jfJoY3uzem3dRyZ79YmjJCv+k36jslxgD0kCdW2SCCe5bRdMLU0vStEj nyUbYIoW5odE5ueAM9oo3CIeIS9yKl+MGes5wJ9y3naTNyQ4QhCLJlFtbmuwvwpLvu IxfLWAM9Goe+RTwL4ArDOlfSFVkKs8xU4joSO25VzhPNEKyGZOPcjfLr7LX0zMAFX1 yzed1AqNRqeIw== Date: Mon, 30 Mar 2026 14:46:51 -0400 From: Mike Snitzer To: Anna Schumaker Cc: Chuck Lever , Cedric Blancher , Linux NFS Mailing List Subject: Re: Increase default NFSv4 server size "max_block_size" to 4MB Message-ID: References: <5acaa8e7-0691-4cbd-b501-c26831a7be81@app.fastmail.com> <88adbb3b-38da-4279-a4b8-db68551d6a8b@app.fastmail.com> Precedence: bulk X-Mailing-List: linux-nfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <88adbb3b-38da-4279-a4b8-db68551d6a8b@app.fastmail.com> On Tue, Mar 17, 2026 at 09:51:23AM -0400, Anna Schumaker wrote: > > > On Mon, Mar 16, 2026, at 8:39 AM, Chuck Lever wrote: > > On Mon, Mar 16, 2026, at 3:51 AM, Cedric Blancher wrote: > >> As debated a while ago, can the default NFSv4 server size for > >> "max_block_size" be increased to 4MB, please? > > > > There is an administrative setting to raise this limit for > > recent versions of the kernel. Can you report your experience > > when you raise the limit? Hiccups, performance issues, etc? I > > would kind of like this exercise to be data-driven. > > > > What is still unknown to me is which NFS client implementations > > can support 4MB or 8MB. Without client support, an increase in > > the default in NFSD doesn't mean anything. Rick, Anna, Roland? > > The NFS client would need a code change to support >1MB sizes. I > spent some time playing around with 4MB yesterday and it passed > all my tests. Is this something you'd be open to posting to the list? Would be interested to see how 'git clone' improves with it. Thanks, Mike