From owner-freebsd-stable@FreeBSD.ORG Wed Oct 15 09:48:12 2008 Return-Path: Delivered-To: freebsd-stable@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 99F97106568B; Wed, 15 Oct 2008 09:48:12 +0000 (UTC) (envelope-from peterjeremy@optushome.com.au) Received: from mail13.syd.optusnet.com.au (mail13.syd.optusnet.com.au [211.29.132.194]) by mx1.freebsd.org (Postfix) with ESMTP id 29BD48FC12; Wed, 15 Oct 2008 09:48:11 +0000 (UTC) (envelope-from peterjeremy@optushome.com.au) Received: from server.vk2pj.dyndns.org (c122-106-215-175.belrs3.nsw.optusnet.com.au [122.106.215.175]) by mail13.syd.optusnet.com.au (8.13.1/8.13.1) with ESMTP id m9F9mAct004863 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Wed, 15 Oct 2008 20:48:11 +1100 X-Bogosity: Ham, spamicity=0.000000 Received: from server.vk2pj.dyndns.org (localhost.vk2pj.dyndns.org [127.0.0.1]) by server.vk2pj.dyndns.org (8.14.2/8.14.2) with ESMTP id m9F9m9Md093570; Wed, 15 Oct 2008 20:48:09 +1100 (EST) (envelope-from peter@server.vk2pj.dyndns.org) Received: (from peter@localhost) by server.vk2pj.dyndns.org (8.14.2/8.14.2/Submit) id m9F9m9GQ093569; Wed, 15 Oct 2008 20:48:09 +1100 (EST) (envelope-from peter) Date: Wed, 15 Oct 2008 20:48:09 +1100 From: Peter Jeremy To: Jeremy Chadwick Message-ID: <20081015094809.GG26536@server.vk2pj.dyndns.org> References: <20081015082428.GE26536@server.vk2pj.dyndns.org> <20081015083538.GA72190@icarus.home.lan> <20081015085843.GF26536@server.vk2pj.dyndns.org> <20081015090848.GA72852@icarus.home.lan> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="Ls2Gy6y7jbHLe9Od" Content-Disposition: inline In-Reply-To: <20081015090848.GA72852@icarus.home.lan> X-PGP-Key: http://members.optusnet.com.au/peterjeremy/pubkey.asc User-Agent: Mutt/1.5.18 (2008-05-17) Cc: freebsd-stable@FreeBSD.org Subject: Re: System hanging during dump X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 15 Oct 2008 09:48:12 -0000 --Ls2Gy6y7jbHLe9Od Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On 2008-Oct-15 02:08:48 -0700, Jeremy Chadwick wrote: >On Wed, Oct 15, 2008 at 07:58:43PM +1100, Peter Jeremy wrote: >> On 2008-Oct-15 01:35:38 -0700, Jeremy Chadwick wrot= e: >> >On Wed, Oct 15, 2008 at 07:24:28PM +1100, Peter Jeremy wrote: >> >> Last night, I attempted a full, compressed backup of my 181GB /home >> >> (on a PATA disk) to a remote system. The backup started at 2159 and >> >> everything appeared normal until about 0040 when the system became >> >> non-responsive and this lasted until the dump completed at 1033. This >> >> is the first full backup of /home I've made for several years (due to >> >> lack of space). >> ... >> >It's a known problem documented in my Wiki -- see "dump/restore". Note >> >the part about UFS2 snapshot generation. I'm almost certain this is >> >what you're describing. >>=20 >> * UFS2 snapshot generation (mksnap_ffs, dump -L) takes too long; system = is unusable during this time >> In my case, snapshot creation took ~4 minutes. The system was >> running normally for 2.6 hours after snapshot creation completed >> before it froze. > >Did you read the References, including the one from myself? Yes. In my case, dump started and ran mksnap_ffs. About 4 minutes later, actual dumping started and data streaming continued for about 12.6 hours. The system froze about 2.6 hours into the dump (after dump had written about 31GB). >Snapshot generation in some cases took only minutes, but *removal* of >the generated the snapshot took 1.5 hours or more, hanging the system >until the removal was complete. Based on progress reports from both dump and my fifo process, the snapshot removal began about 10 hours _after_ the system froze (during this time, dump wrote about 143GB). Given the timeline, it's fairly clear that neither mksnap_ffs nor the 'rm snapshot' were running at the time the system froze. I am therefore quite confident that the problem I saw is not related to either creation or removal of snapshots. I have been using FreeBSD snapshots for many years and am quite familiar with their quirks. I have never seen this particular problem before. (And FWIW, I _am_ using Doug Ambrisko's patch to ffs_snapshot.c). --=20 Peter Jeremy Please excuse any delays as the result of my ISP's inability to implement an MTA that is either RFC2821-compliant or matches their claimed behaviour. --Ls2Gy6y7jbHLe9Od Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.9 (FreeBSD) iEYEARECAAYFAkj1vFkACgkQ/opHv/APuIfmUgCdEe0Dhb8rl/ex8rl4qe2p7ZvO WaUAoIvgREtW4FIiV62mWHtiC90vZDx6 =FpOu -----END PGP SIGNATURE----- --Ls2Gy6y7jbHLe9Od--