From owner-freebsd-stable@FreeBSD.ORG Thu Nov 13 08:35:12 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 8A179106567E; Thu, 13 Nov 2008 08:35:12 +0000 (UTC) (envelope-from tdb@carrick.bishnet.net) Received: from carrick.bishnet.net (carrick.bishnet.net [IPv6:2a01:348:132::1]) by mx1.freebsd.org (Postfix) with ESMTP id 491278FC14; Thu, 13 Nov 2008 08:35:11 +0000 (UTC) (envelope-from tdb@carrick.bishnet.net) Received: from tdb by carrick.bishnet.net with local (Exim 4.66 (FreeBSD)) (envelope-from ) id 1L0XfM-000Kwj-Sd; Thu, 13 Nov 2008 08:35:04 +0000 Date: Thu, 13 Nov 2008 08:35:04 +0000 From: Tim Bishop To: Jeremy Chadwick Message-ID: <20081113083504.GF24360@carrick.bishnet.net> References: <20081112175826.GD26195@carrick.bishnet.net> <20081112194735.GK47073@deviant.kiev.zoral.com.ua> <20081113004102.GD24360@carrick.bishnet.net> <20081113044200.GA10419@icarus.home.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20081113044200.GA10419@icarus.home.lan> X-PGP-Key: 0x5AE7D984, http://www.bishnet.net/tim/tim-bishnet-net.asc X-PGP-Fingerprint: 1453 086E 9376 1A50 ECF6 AE05 7DCE D659 5AE7 D984 User-Agent: Mutt/1.5.13 (2006-08-11) X-Bishnet-MailScanner-Information: Contact postmaster@bishnet.net X-Bishnet-MailScanner-VirusCheck: Found to be clean X-Bishnet-MailScanner-SpamCheck: not spam, SpamAssassin (not cached, score=-1.087, required 5, BAYES_00 -2.60, DNS_FROM_SECURITYSAGE 1.51, NO_RELAYS -0.00) X-Bishnet-MailScanner-From: tdb@carrick.bishnet.net Cc: Kostik Belousov , Tim Bishop , freebsd-stable@freebsd.org Subject: Re: System deadlock when using mksnap_ffs 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: Thu, 13 Nov 2008 08:35:12 -0000 Jeremy, On Wed, Nov 12, 2008 at 08:42:00PM -0800, Jeremy Chadwick wrote: > On Thu, Nov 13, 2008 at 12:41:02AM +0000, Tim Bishop wrote: > > On Wed, Nov 12, 2008 at 09:47:35PM +0200, Kostik Belousov wrote: > > > On Wed, Nov 12, 2008 at 05:58:26PM +0000, Tim Bishop wrote: > > > > I run the mksnap_ffs command to take the snapshot and some time later > > > > the system completely freezes up: > > > > > > > > paladin# cd /u2/.snap/ > > > > paladin# mksnap_ffs /u2 test.1 > > > > > > You need to provide information described in the > > > http://www.freebsd.org/doc/en_US.ISO8859-1/books/developers-handbook/kerneldebug.html > > > and especially > > > http://www.freebsd.org/doc/en_US.ISO8859-1/books/developers-handbook/kerneldebug-deadlocks.html > > > > Ok, I've done that, and removed the patch that seemed to fix things. > > > > The first thing I notice after doing this on the console is that I can > > still ctrl+t the process: > > > > load: 0.14 cmd: mksnap_ffs 2603 [newbuf] 0.00u 10.75s 0% 1160k > > > > But the top and ps I left running on other ttys have all stopped > > responding. > > Then in my book, the patch didn't fix anything. :-) The system is > still "deadlocking"; snapshot generation **should not** wedge the system > hard like this. You missed the part where I said I "removed the patch". I did that so I could provide details with it wedged. I agree that there's still some fundamental speed issues with snapshotting though. And I'm sure the FS itself will still be locked out for a while during the snapshot. But with the patch at least the whole thing doesn't lock up. Tim. -- Tim Bishop http://www.bishnet.net/tim/ PGP Key: 0x5AE7D984