From owner-freebsd-fs@FreeBSD.ORG Tue Aug 28 08:13:51 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 94FE0106564A; Tue, 28 Aug 2012 08:13:51 +0000 (UTC) (envelope-from mad@madpilot.net) Received: from micro.madpilot.net (micro.madpilot.net [88.149.173.206]) by mx1.freebsd.org (Postfix) with ESMTP id 2C47A8FC15; Tue, 28 Aug 2012 08:13:51 +0000 (UTC) Received: from micro.madpilot.net (localhost [127.0.0.1]) by micro.madpilot.net (Postfix) with ESMTP id 3X5jR175TMz29D; Tue, 28 Aug 2012 10:13:49 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=madpilot.net; h= user-agent:in-reply-to:content-disposition:content-type :content-type:mime-version:references:message-id:subject:subject :from:from:date:date:received:received; s=mail; t=1346141624; x= 1347956025; bh=I12sSkfX5OeQPF5FNaMHIgvL5bEspIjRj3fAPKmFgr0=; b=V GrvwNlgj/7tgl/t4mE16fZrrv6vmHzE5jXqWE6QdtT72iTaogF/lZ8s6RY+GdVxc aFfHVui6wU7mJoAAQ7fI4VE+tJnqHhllC0Ove8aPScqOxAofBjdAuGx5t8UBjFRr e/kjmzRUemGh5Fc5J3KdPQybzuj9nD2ldhecQlOxew= X-Virus-Scanned: amavisd-new at madpilot.net Received: from micro.madpilot.net ([127.0.0.1]) by micro.madpilot.net (micro.madpilot.net [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id VzDkTgpxqilb; Tue, 28 Aug 2012 10:13:44 +0200 (CEST) Received: by micro.madpilot.net (Postfix, from userid 1000) id 3X5jQw2rdJz29C; Tue, 28 Aug 2012 10:13:44 +0200 (CEST) Date: Tue, 28 Aug 2012 10:13:44 +0200 From: Guido Falsi To: Matthew Seaman Message-ID: <20120828081344.GA20350@micro.madpilot.net> References: <503C5F2A.701@FreeBSD.org> <503C633B.2070508@madpilot.net> <503C66C2.5010209@FreeBSD.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <503C66C2.5010209@FreeBSD.org> X-Operating-System: FreeBSD 9.1-PRERELEASE User-Agent: Mutt/1.5.21 (2010-09-15) Cc: freebsd-fs@FreeBSD.org Subject: Re: ZFS snapshot Folder Disappearing 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: Tue, 28 Aug 2012 08:13:51 -0000 On Tue, Aug 28, 2012 at 07:35:46AM +0100, Matthew Seaman wrote: > > I got hit by this a few times too. Ti me it looks like it's easier to > > get this problem on more low spec machines(low spec regarding ZFS, so > > anything under 3-4 GiB ram is on the low side, for example). > > My machine has 8GB RAM which I wouldn't call low spec particularly. No, Definitely not. But in my experience when I have upgraded machines showing this problem it's frequency decreased a lot. > > > Using nullfs across snapshots did trigger this easily. I did that to > > have a nullfs mounted snapshot of the whole filesystem structure. I'm > > using read only zfs clones for that now. > > Interesting. I do have certain ZFSes null-mounted into a jail. I > wonder if that's a common factor? That could be a common trigger in my opinion, but it just exposes some other problem. I know very little about ZFS internals so I have been unable to dig any further. -- Guido Falsi