From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0AF4EC433F5 for ; Wed, 22 Sep 2021 09:48:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D87CD610A1 for ; Wed, 22 Sep 2021 09:48:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234288AbhIVJtn (ORCPT ); Wed, 22 Sep 2021 05:49:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46928 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234233AbhIVJtn (ORCPT ); Wed, 22 Sep 2021 05:49:43 -0400 Received: from mail-ed1-x52d.google.com (mail-ed1-x52d.google.com [IPv6:2a00:1450:4864:20::52d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 18B00C061574 for ; Wed, 22 Sep 2021 02:48:13 -0700 (PDT) Received: by mail-ed1-x52d.google.com with SMTP id v24so7720623eda.3 for ; Wed, 22 Sep 2021 02:48:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=dneg.com; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=qceiZJW+xNuPv6DC8Ddv9FCnq8sX7E1T/cLTUPwqWEI=; b=W4DnfMgdaR/KzheXlvRl+xb/caTettvk56FczFBf1MvCyCiE0Pg9FI0B7Ghq3EzDQA yNrURYUJ+3iFprxCGyDcgN5uYyAE/ntZz3mnCMTUnW6OyGrYmM3ALiVYE5Bdq16O/Im8 tNuSvTlwHhHRXf1wD02GWryGuA0LcQRm67CRIC1c2YHZAiusSLfaiVjxNj8HrZYXUxvP FmyMs1WKIqXzr2LVqo/AlRu9K3X6eHUL9HqomKwFQWrt2S5f/44mXmrvmNxh11U6NUlE wU2NfRpznZXfSmP5gICxgNOcyXljSjG0/g30K0ldmo/Z+kf6/tU/Cm2vYNRro00njGlv 5cxQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=qceiZJW+xNuPv6DC8Ddv9FCnq8sX7E1T/cLTUPwqWEI=; b=3tmn/ybj/lMbEd787BQFvnN7W8oYv0b6fT8VzK9yxGdGSPSHjh4497zK42x6gxhxl1 oGqEmUlJwEJrRfEuenLBFtrRR7JT3TOMW8JTE3YgsY3uL4YJXU1E/C681f+Xp2MzMgMS 6RQYu1d9mlwBuenmK+b9FLEl7v2B4r45pwAnk+C/SVdzmonao1Fy3A8RLDypIBo7WmVK Q0ZbxzlyIcfudN2z9mXRAEgufxpkovMxnFyUsIeoIrBuu55n5Uj6UEJHieVO6MbVavOf RcEPb2ZSjZgx/2TF8VKLkYPUB7RZ1wSKF17QvH1qCq2gfIBB1otDycPrILz5wTTT4pAT 6cvQ== X-Gm-Message-State: AOAM532YqKwGgJLiFBrkjvX7wLW/qHFfHTB1VQD4nTasfL4GHICqATHR Y34hrBjWscWC0EYaw5X18HX7RQZi7sfidIFJO1mOyQ== X-Google-Smtp-Source: ABdhPJwOItM4/kumpCdPGX63zXOJImLAqUljPGeP3BP972olG9mw0oXDNowo/+aHVOM7yjbevRT35w0MVBJiXc+DwiE= X-Received: by 2002:a17:906:3745:: with SMTP id e5mr40672498ejc.400.1632304091632; Wed, 22 Sep 2021 02:48:11 -0700 (PDT) MIME-Version: 1.0 References: <20210921143259.GB21704@fieldses.org> <37851433-48C9-4585-9B68-834474AA6E06@oracle.com> <20210921160030.GC21704@fieldses.org> In-Reply-To: <20210921160030.GC21704@fieldses.org> From: Daire Byrne Date: Wed, 22 Sep 2021 10:47:35 +0100 Message-ID: Subject: Re: [PATCH] nfs: reexport documentation To: Bruce Fields Cc: Chuck Lever III , Linux NFS Mailing List Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org On Tue, 21 Sept 2021 at 17:00, Bruce Fields wrote: > > > Any recommended workarounds? Or does this simply mean that > > administrators need to notify client users to unmount (or > > at least stop their workloads) before rebooting the proxy? > > I think so. > > If you don't use any file locking or delegations I suppose you're also > OK. Delegations might be useful, though. > > I'd expect reexport to be useful mainly for data that changes very > rarely, if that helps. > > --b. Firstly, it's great to see this documentation and the well maintained wiki page for something we use in production (a lot) - thanks Bruce! I can only draw on our experience to say: * if the nfs re-export server doesn't crash, we rarely have cause to reboot it. * we re-export read-only software repositories to WAN/cloud instances (an ideal use case). * we also re-export read/write production storage but every client process is writing unique files - there are no writes to the same file(s) from any clients of the re-export server. We don't use or need crossmnt functionality, but I know from chatting to others within our industry that the fsid/crossmnt limitation causes them the most grief and confusion. I think in the case of Netapps, there are similar problems with trying to re-export a namespace made up of different volumes? As noted on the wiki, the only way around that is probably to have a "proxy" mode (similar to what ganesha does?). Daire