From owner-freebsd-stable@FreeBSD.ORG Tue Mar 9 10:54:00 2010 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 DA44B106566B for ; Tue, 9 Mar 2010 10:54:00 +0000 (UTC) (envelope-from peterjeremy@acm.org) Received: from mail35.syd.optusnet.com.au (mail35.syd.optusnet.com.au [211.29.133.51]) by mx1.freebsd.org (Postfix) with ESMTP id 6B53A8FC13 for ; Tue, 9 Mar 2010 10:54:00 +0000 (UTC) Received: from server.vk2pj.dyndns.org (c122-106-253-149.belrs3.nsw.optusnet.com.au [122.106.253.149]) by mail35.syd.optusnet.com.au (8.13.1/8.13.1) with ESMTP id o29AruGW020916 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Tue, 9 Mar 2010 21:53:57 +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 (8.14.3/8.14.3) with ESMTP id o29ArtMo005360; Tue, 9 Mar 2010 21:53:55 +1100 (EST) (envelope-from peter@server.vk2pj.dyndns.org) Received: (from peter@localhost) by server.vk2pj.dyndns.org (8.14.3/8.14.3/Submit) id o29Artts005359; Tue, 9 Mar 2010 21:53:55 +1100 (EST) (envelope-from peter) Date: Tue, 9 Mar 2010 21:53:55 +1100 From: Peter Jeremy To: Stefan Bethke Message-ID: <20100309105355.GD3978@server.vk2pj.dyndns.org> References: <864468D4-DCE9-493B-9280-00E5FAB2A05C@lassitu.de> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="4zI0WCX1RcnW9Hbu" Content-Disposition: inline In-Reply-To: <864468D4-DCE9-493B-9280-00E5FAB2A05C@lassitu.de> X-PGP-Key: http://members.optusnet.com.au/peterjeremy/pubkey.asc User-Agent: Mutt/1.5.20 (2009-06-14) Cc: FreeBSD Stable Subject: Re: Many processes stuck in zfs 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: Tue, 09 Mar 2010 10:54:00 -0000 --4zI0WCX1RcnW9Hbu Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On 2010-Mar-09 10:15:53 +0100, Stefan Bethke wrote: >Over the past couple of months, I've more or less regularly observed machi= nes having more and more processes stuck in the zfs wchan. The processes n= ever recover from that, How long have you waited? There seems to be a problem with low free memory handling that causes ZFS to turn into cold molasses. The work-around is to run a program that allocates a decent size chunk of memory and then exits. The original suggestion was something like: perl -e '@x =3D (0) x 1000000;' I've written a short program that allocates and dirties ~100MB and then exits and run it from cron. --=20 Peter Jeremy --4zI0WCX1RcnW9Hbu Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.14 (FreeBSD) iEYEARECAAYFAkuWKMMACgkQ/opHv/APuIfMnACfXdRRLq7lnwMLvxpAIXxBySj/ QtgAmwUTQ5iSzx0QuxXcjq3kT0VKn8fb =L+vJ -----END PGP SIGNATURE----- --4zI0WCX1RcnW9Hbu--