From owner-freebsd-stable@freebsd.org Fri Aug 5 14:11:13 2016 Return-Path: Delivered-To: freebsd-stable@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 20478BB0749 for ; Fri, 5 Aug 2016 14:11:13 +0000 (UTC) (envelope-from asomers@gmail.com) Received: from mail-oi0-x234.google.com (mail-oi0-x234.google.com [IPv6:2607:f8b0:4003:c06::234]) (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 D6EE71C3F for ; Fri, 5 Aug 2016 14:11:12 +0000 (UTC) (envelope-from asomers@gmail.com) Received: by mail-oi0-x234.google.com with SMTP id f189so90695473oig.3 for ; Fri, 05 Aug 2016 07:11:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:from:date:message-id :subject:to:cc; bh=irkkYFavEtBZinsZGto7Ii8NPoHP3fzc+U6ZB+P7ifA=; b=hC3CzHG7/+T+ktNCpM+7YHwQzpdzVJb4XUEeIccIfwLz/YEhy8O1yW+prx6TRTSMTe ygbAHAOsPKvMe5DfOWE2+Qm9nnpmZlMi8bU+v+G38gH3htF+EBnyOapD+RMX1Wxz/jae kHBMrZXNffdqaOwrB1EBqKnCheZFyzwBrsa3j0kYpj9UxGYBRtL353hlMZrYe8uq0Etn Dlrpjwp+0gdKV4Q5AZz5pQc6otM1cYom/Oy6wDh1BFeqigfKBrtlCtcf1L5roDT5wcWU oQR5YPqlB7aFYCzsRAa3hdVxvjMNOalug7g8DdKSYNWwZPDgTHK929AC6cpcwuz3HA25 c5BA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:sender:in-reply-to:references:from :date:message-id:subject:to:cc; bh=irkkYFavEtBZinsZGto7Ii8NPoHP3fzc+U6ZB+P7ifA=; b=k3nVudMFnjHdOOSZYRe5i29HHDURsxucNc1ZT2YQPMhpp+J9N41ePP5czbHidL21id cHYUxgAjUq9kCbeK0T9Zvgy2WHcEvsp3XrLOHqveGjd2gF6rz5WlBQ0ocqU+kLVVqKzz s9v4XjTZwNksTqdjEWDD4QvB2KyjcuH/lLiXE8size1dWQ1xSbdUSiDwyDWLdpCx9lLR mk7F0PoIIC4HAYbDenhwcY5R/oRh/7vwEKFxKJtR3Dr6tcRD4/u15EDpj/Hc6JtoesF5 ERrRjUKShOiewMhG6SfvmtvZvoesddJKuTWQoOZ+aNlPBWGzCfVxiCNU5DZoAjyPny6G VPhA== X-Gm-Message-State: AEkoousO+OZafTxn/SPP/4estS+XDh8fR48jrS0L/LnWH7rAmT1YEStcOD72hzEsXWzC1QmlpbcxSvDGdkjPvw== X-Received: by 10.157.9.175 with SMTP id q44mr1319743otd.164.1470406272102; Fri, 05 Aug 2016 07:11:12 -0700 (PDT) MIME-Version: 1.0 Sender: asomers@gmail.com Received: by 10.202.196.149 with HTTP; Fri, 5 Aug 2016 07:11:11 -0700 (PDT) In-Reply-To: <1df33129-0c3e-dfc3-6867-46ab0473ae57@gmx.de> References: <1df33129-0c3e-dfc3-6867-46ab0473ae57@gmx.de> From: Alan Somers Date: Fri, 5 Aug 2016 08:11:11 -0600 X-Google-Sender-Auth: JVzDq9ZgL7H2VyMIJ4I4ZXyz3CA Message-ID: Subject: Re: zfs recv causes nfs server to throw NFSERR_IO i/o errors To: Daniel Genis Cc: FreeBSD Content-Type: text/plain; charset=UTF-8 X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.22 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 05 Aug 2016 14:11:13 -0000 On Fri, Aug 5, 2016 at 7:22 AM, Daniel Genis wrote: > Hi everyone, > > we've been tracing an issue where snapshot replication is causing > interruptions for the NFS serivce. > > The problem is as follows: > > Every time a zfs recv finishes, there is a chance for the NFS server to > return an NFSERR_IO for a GETATTR call. This shows up as input/output > errors on the nfs clients. > > Here the tcpdump showing the NFS conversation: > https://nopaste.me/view/95d1a79d > > NFS 202 V3 GETATTR Call (Reply In 6043), FH: 0x8c711a60 > NFS 98 V3 GETATTR Reply (Call In 6042) Error: NFS3ERR_IO > NFS 222 V3 LOOKUP Call (Reply In 6046), DH: 0x6694634f/example.file.txt > NFS 102 V3 LOOKUP Reply (Call In 6045) Error: NFS3ERR_ACCES > > We've been able to verify that there is a _direct_ correlation between > the zfs recv command and these NFS errors. For every input/output error > we can find a log entry of a replication just finishing (zfs recv exiting). > > The receiving server is running 10.3-RELEASE > > I've read about a VFS/ZFS deadlock issue which is to be included/fixed > in Freebsd 11.0-BETA4. > > Could our issue be related? > Otherwise does anyone have any suggestions how to tackle this issue? > > > For the record, say we have two volumes: > tank/volumeA and tank/volumeB > > If there is a zfs recv busy for tank/volumeA then tank/volumeB can get > these NFS "io" errors, it does not have to be the same volume. > > > Has anyone else seen/experience this as well? > > Any insights are appreciated! > > With kind regards, > > Daniel Try adding mountd_flags="-S" to /etc/rc.conf.