From owner-freebsd-fs@FreeBSD.ORG Sun Feb 12 08:40:54 2012 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 648701065672 for ; Sun, 12 Feb 2012 08:40:54 +0000 (UTC) (envelope-from jdc@koitsu.dyndns.org) Received: from qmta13.emeryville.ca.mail.comcast.net (qmta13.emeryville.ca.mail.comcast.net [76.96.27.243]) by mx1.freebsd.org (Postfix) with ESMTP id 4C3A78FC08 for ; Sun, 12 Feb 2012 08:40:53 +0000 (UTC) Received: from omta03.emeryville.ca.mail.comcast.net ([76.96.30.27]) by qmta13.emeryville.ca.mail.comcast.net with comcast id YwfU1i0050b6N64ADwgtuK; Sun, 12 Feb 2012 08:40:53 +0000 Received: from koitsu.dyndns.org ([67.180.84.87]) by omta03.emeryville.ca.mail.comcast.net with comcast id Ywgt1i00F1t3BNj8PwgtAh; Sun, 12 Feb 2012 08:40:53 +0000 Received: by icarus.home.lan (Postfix, from userid 1000) id 0168E102C1E; Sun, 12 Feb 2012 00:40:52 -0800 (PST) Date: Sun, 12 Feb 2012 00:40:52 -0800 From: Jeremy Chadwick To: Matthew Seaman Message-ID: <20120212084052.GA43095@icarus.home.lan> References: <4F377457.4080807@FreeBSD.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4F377457.4080807@FreeBSD.org> User-Agent: Mutt/1.5.21 (2010-09-15) Cc: freebsd-fs@FreeBSD.org Subject: Re: ZFS Snapshot problems X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 12 Feb 2012 08:40:54 -0000 On Sun, Feb 12, 2012 at 08:12:07AM +0000, Matthew Seaman wrote: > > Since about a week ago I've been intermittently getting a problem where > I cannot access a snapshot after creating it: > > lucid-nonsense:~:# zfs snapshot zroot@test > lucid-nonsense:~:# zfs list -t snapshot > NAME USED AVAIL REFER MOUNTPOINT > zroot@test 67K - 8.36G - > lucid-nonsense:~:# cd /.zfs/snapshot/test > /.zfs/snapshot/test: Not a directory. > > This is playing silly buggers with my backups. Apart from that, the > system is behaving normally. Nothing in syslog, nothing in dmesg. > The only way I've found so far to clear the problem is to reboot, but > then the problem seems to recur within a few days. > > 'zpool status' says everything is fine. 'zpool scrub' has no effect. > > lucid-nonsense:~:# uname -a > FreeBSD lucid-nonsense.infracaninophile.co.uk 8.2-STABLE FreeBSD > 8.2-STABLE #2 r231394: Fri Feb 10 20:35:13 GMT 2012 > root@lucid-nonsense.infracaninophile.co.uk:/usr/obj/usr/src/sys/LUCID-NONSENSE > amd64 > lucid-nonsense:~:# zpool upgrade > This system is currently running ZFS pool version 28. > > All pools are formatted using this version. > lucid-nonsense:~:# zfs upgrade > This system is currently running ZFS filesystem version 5. > > All filesystems are formatted with the current version. > > Any clues about how I can debug this, and hopefully prevent it happening? Could this be related (somehow) to the below commit? I'm doubting it, but... http://www.freebsd.org/cgi/cvsweb.cgi/src/cddl/contrib/opensolaris/cmd/zfs/zfs_main.c I realise you're not destroying a snapshot, but I wonder if an old snapshot which was previously destroyed wasn't really destroyed, thus resulting in the behaviour you see. As stated, I doubt it, but I imagine it depends on how this issue manifests itself. -- | Jeremy Chadwick jdc@parodius.com | | Parodius Networking http://www.parodius.com/ | | UNIX Systems Administrator Mountain View, CA, US | | Making life hard for others since 1977. PGP 4BD6C0CB |