From owner-freebsd-current@FreeBSD.ORG Tue Feb 1 16:28:03 2011 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id F02E31065673 for ; Tue, 1 Feb 2011 16:28:03 +0000 (UTC) (envelope-from luke@digital-crocus.com) Received: from mail.digital-crocus.com (node2.digital-crocus.com [91.209.244.128]) by mx1.freebsd.org (Postfix) with ESMTP id A5D4D8FC1B for ; Tue, 1 Feb 2011 16:28:03 +0000 (UTC) DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=dkselector; d=hybrid-logic.co.uk; h=Received:Received:Subject:From:Reply-To:To:Content-Type:Organization:Date:Message-ID:Mime-Version:X-Mailer:Content-Transfer-Encoding:X-Spam-Score:X-Digital-Crocus-Maillimit:X-Authenticated-Sender:X-Complaints:X-Admin:X-Abuse; b=OP9VqLUs0iPPAM4FNX7pGcDgcBmcxt7UeSn52b+201H4uIcLNnY6UlQpDo9uh4wif3A52GlEemCwcumSagGsHgWL0rEBGddzEtQ+s+YDwNxRosMim7uozvrnbbtpzVXy; Received: from luke by mail.digital-crocus.com with local (Exim 4.69 (FreeBSD)) (envelope-from ) id 1PkJ5F-0002EC-Ue for freebsd-current@freebsd.org; Tue, 01 Feb 2011 16:28:01 +0000 Received: from c-76-118-178-109.hsd1.ma.comcast.net ([76.118.178.109] helo=[192.168.1.51]) by mail.digital-crocus.com with esmtpa (Exim 4.69 (FreeBSD)) (envelope-from ) id 1PkJ5E-0002DK-Ko; Tue, 01 Feb 2011 16:28:01 +0000 From: Luke Marsden To: freebsd-stable@freebsd.org, freebsd-fs@FreeBSD.org, freebsd-current@FreeBSD.org Content-Type: text/plain; charset="UTF-8" Organization: Hybrid Web Cluster Date: Tue, 01 Feb 2011 11:27:59 -0500 Message-ID: <1296577679.2222.21.camel@pow> Mime-Version: 1.0 X-Mailer: Evolution 2.30.3 Content-Transfer-Encoding: 7bit X-Spam-Score: -1.0 X-Digital-Crocus-Maillimit: done X-Authenticated-Sender: luke X-Complaints: abuse@digital-crocus.com X-Admin: admin@digital-crocus.com X-Abuse: abuse@digital-crocus.com (Please include full headers in abuse reports) X-Mailman-Approved-At: Tue, 01 Feb 2011 16:59:48 +0000 Cc: Subject: ZFS hanging with simultaneous "zfs recv" and "zfs umount -f" X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: luke@hybrid-logic.co.uk List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 01 Feb 2011 16:28:04 -0000 Hi FreeBSD-{stable,current,fs}, I've reliably been able to cause the ZFS subsystem to hang under FreeBSD 8.1-RELEASE under the following conditions: Another server is sending the server an incremental snapshot stream which is in the process of being received with: zfs send -I $OLD $FS@$NEW |ssh $HOST zfs recv -uF $FILESYSTEM On the receiving server, we forcibly unmount the filesystem which is being received into with: zfs umount -f $FILESYSTEM (the filesystem may or may not actually be mounted) This causes any ZFS file operation (such as "ls") to hang forever and when attempting to reboot the machine, it goes down and stops responding to pings, but then hangs somewhere in the reboot process and needs a hard power cycle. Unfortunately we don't have a remote console on this machine. I understand this is a fairly harsh use case but the ideal behaviour would be for the zfs recv to emit an error message (if necessary) rather than rendering the entire machine unusable ;-) Let me know if you need any further information. I appreciate that providing a script to reliably reproduce the problem, testing on -CURRENT and 8.2-PRE, and submitting a bug report will help... I will do this in due course, but don't have time right now -- just wanted to get this bug report out there first in case there's an obvious fix. Thank you for supporting ZFS on FreeBSD!! -- Best Regards, Luke Marsden CTO, Hybrid Logic Ltd. Web: http://www.hybrid-cluster.com/ Hybrid Web Cluster - cloud web hosting Phone: +441172232002 / +16179496062