From owner-freebsd-fs@freebsd.org Tue Jul 31 21:32:14 2018 Return-Path: Delivered-To: freebsd-fs@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id AFDD91065AD6 for ; Tue, 31 Jul 2018 21:32:14 +0000 (UTC) (envelope-from fjwcash@gmail.com) Received: from mail-lj1-x236.google.com (mail-lj1-x236.google.com [IPv6:2a00:1450:4864:20::236]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 296717E74B; Tue, 31 Jul 2018 21:32:14 +0000 (UTC) (envelope-from fjwcash@gmail.com) Received: by mail-lj1-x236.google.com with SMTP id u7-v6so15042848lji.3; Tue, 31 Jul 2018 14:32:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=b/+vVOFuaNykVj1XnMcHciEjNsxy73fs97lB2VdrPQQ=; b=faUMWzCWkJ0CtuN8at6emKVq4ljSkaEQW/wZfPyEDXBvDEzaKxNFdYxGhoxQrPe3Sf z7S10U2IUGqm4WvzXjgYbneczjolvsTkv8CucuwI61nugUzbPygFgmqCxiRl555Rj+am YUU3dEznn4iBDtj0yoFoSQlYCU68SaRcOWEwgvngVrRGtDT4VuEURycAh64zHtuUvF+7 hNXqA4IlThR5+1dEt5qhqmDmNe33vSjynJ2cA6pwdOmsl/t/Q3sAJtHXwyvQhdzLS6ZL KoptORNkq/OE9uP3597+ZW982iqnetkbcRIkrZ+/zprSF+c8ZKLF4FGGZ3OzMARZrzo+ Qstw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=b/+vVOFuaNykVj1XnMcHciEjNsxy73fs97lB2VdrPQQ=; b=H5SZZNnp6nnnkcDgZIuyR4eQL7XL7qzJdvJdMwQYRCOCMLfcQpxh//2EQ0Wlye0orf vdYcnXqDYq0kyFDvKBe2Uv6piXsc0js/oJFeeUQrRzLaidVwWxUVbEnmvV0+C+dCKdPo qw+WSZSr2Vh7cxDMeE/bY/vGcNPieuUp0tZz9abUl6HlXlYb8vJlY5v3r7xrt52DjG7Y AywFNNPrjpCGyTf1td6Z5B5Z48i7kEy+EyeR0bWigwRete3z0GwMyUOVUFqhGFgvqh5H djASptv4JXimdsLxJqEh56TU+46uPby72FN5JPZ15wbOw//8mG2YJyssVCkWY0c7hFO1 E6SQ== X-Gm-Message-State: AOUpUlHHeOhDcIaJNQkmd4jmonYpd/zJTfw3CsL26oxRf/17I17tqPxz DO4tMuSEQVRPzXN/v2qqJ5hLodT2sH8QJlnol2EsQw== X-Google-Smtp-Source: AAOMgpfwgOF1tk+eFvQTEzxKDmLhioOK1Y/wtUIxgwvvZk1A1H50WYB8iztUt0wdZad21sIJxfz2GpCkvanfa27Pf7U= X-Received: by 2002:a2e:89c5:: with SMTP id c5-v6mr18649102ljk.19.1533072732671; Tue, 31 Jul 2018 14:32:12 -0700 (PDT) MIME-Version: 1.0 References: <20180731212355.GA19206@FreeBSD.org> In-Reply-To: <20180731212355.GA19206@FreeBSD.org> From: Freddie Cash Date: Tue, 31 Jul 2018 14:32:01 -0700 Message-ID: Subject: Re: Nfsroot .zfs/snapshot mounted on different mount? To: John Cc: FreeBSD Filesystems Content-Type: text/plain; charset="UTF-8" X-Content-Filtered-By: Mailman/MimeDel 2.1.27 X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.27 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 31 Jul 2018 21:32:14 -0000 On Tue, Jul 31, 2018 at 2:25 PM John wrote: > Hi Folks, > > I ran into something today I didn't expect and was wondering > how it is accomplished - or something is going on in the NFS > code I've never seen. > > I have some remote nfs booted systems where the OS lives > on ZFS volumes (the client is linux):. > > 10.121.56.21:/vol/nfsbt_sysgpu01 100G 4.7G 96G 5% / > > After installing the latest gpu drivers I was asked to > compare a few things and went into the /.zfs/snapshot directory > as typical. However, I then noticed a 2nd nfs mount had > appeared: > > 10.121.56.21:/vol/nfsbt_sysgpu01/.zfs/snapshot/rb_20180727-185554_drivers > 100G 4.7G 96G 5% /.zfs/snapshot/rb_20180727-185554_drivers > > To my knowledge, I have no auto-mounter that could have done > the mount. I'm curious where this is hooked in. > > The server is: > > FreeBSD 11.1-STABLE #11 r327104: Sat Dec 23 08:19:22 EST 2017 > > with standard nfsv3 exports. Other than this curiousness > the system is flawless. > Not sure about the NFS side of things, but the FreeBSD kernel has auto-mounted the .zfs/snapshot/ filesystem upon access from the first ZFS import into FreeBSD 7. Depending on how the NFS mount is setup, this may be carrying-over from the kernel auto-mount. -- Freddie Cash fjwcash@gmail.com