From owner-freebsd-fs@freebsd.org Sun Oct 11 13:37:36 2015 Return-Path: Delivered-To: freebsd-fs@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 3F38CA0FC9A for ; Sun, 11 Oct 2015 13:37:36 +0000 (UTC) (envelope-from michael@ranner.eu) Received: from mail.azedo.at (mail.azedo.at [91.118.6.139]) by mx1.freebsd.org (Postfix) with ESMTP id D4CBB139 for ; Sun, 11 Oct 2015 13:37:35 +0000 (UTC) (envelope-from michael@ranner.eu) Received: from mail.azedo.at (mail.azedo.at [172.20.10.3]) by mail.azedo.at (Postfix) with ESMTP id 2FE3CA83015; Sun, 11 Oct 2015 15:37:33 +0200 (CEST) X-Virus-Scanned: amavisd-new at azedo.at Received: from mail.azedo.at ([172.20.10.3]) by mail.azedo.at (mail.azedo.at [172.20.10.3]) (amavisd-new, port 10024) with ESMTP id 9aRig--XbHjZ; Sun, 11 Oct 2015 15:37:19 +0200 (CEST) Received: from lynx.local (80-121-99-80.adsl.highway.telekom.at [80.121.99.80]) by mail.azedo.at (Postfix) with ESMTPSA id 6E0C6A83018; Sun, 11 Oct 2015 15:37:19 +0200 (CEST) Subject: Re: Zfs locking up process To: Steven Hartland , freebsd-fs@freebsd.org References: <561A2A4B.4080704@ranner.eu> <561A5445.40603@multiplay.co.uk> From: Michael Ranner Message-ID: <561A660E.1020905@ranner.eu> Date: Sun, 11 Oct 2015 15:37:18 +0200 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.10; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 MIME-Version: 1.0 In-Reply-To: <561A5445.40603@multiplay.co.uk> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-Content-Filtered-By: Mailman/MimeDel 2.1.20 X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 11 Oct 2015 13:37:36 -0000 Am 11.10.15 um 14:21 schrieb Steven Hartland: > > > On 11/10/2015 10:22, Michael Ranner wrote: >> Am 07.10.15 um 17:11 schrieb Rajil Saraswat: >>> Hello >>> >>> I have server running Freenas 9.3 with a few jails. The machine has >>> two new >>> disks setup in mirror. I have a dataset (/mnt/tank/media) which is >>> shared >>> in two jails. >>> >>> Unfortunately, sometimes when I do a ls in a jail in the shared >>> directory I >>> see that the process just hangs. >>> >>> Today in the jail I did an 'su' and process just hung. On the host >>> if i do >>> ls /mnt/tank/media it also hangs. >>> >>> The su process (pid 77477) is taking up 100% cpu in the jail. It >>> seems that >>> zfs is holding up the process. Any idea what could be wrong? >>> >>> >> It is a known problem with ZFS and nullfs. I had no problems under >> FreeBSD 8 witch such a setup, but since FreeBSD 9 it is very unstable to >> mount_nullfs on ZFS. I experienced the same behaviour with Apache jails >> and PHP, mostly PHP running with 100% CPU inside the jail. > I'd have to disagree with this we have hundreds of machines on 10.1 > which uses nullfs every day and we've never seen a lockup. > > Given that do you have more information about this e.g. PR? There are some posts to freebsd-fs in 2014 like this: https://lists.freebsd.org/pipermail/freebsd-fs/2014-November/020482.html And an in depth insight von Andriy Gapon: https://lists.freebsd.org/pipermail/freebsd-fs/2014-September/020072.html The problem will become more frequently with heavy snapshot usage on the underlying ZFS datasets. Regards Michael