From owner-freebsd-fs@FreeBSD.ORG Tue Jul 31 15:31:35 2012 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 6CF941065673 for ; Tue, 31 Jul 2012 15:31:35 +0000 (UTC) (envelope-from fjwcash@gmail.com) Received: from mail-lpp01m010-f54.google.com (mail-lpp01m010-f54.google.com [209.85.215.54]) by mx1.freebsd.org (Postfix) with ESMTP id 967DB8FC19 for ; Tue, 31 Jul 2012 15:31:34 +0000 (UTC) Received: by laai10 with SMTP id i10so4960424laa.13 for ; Tue, 31 Jul 2012 08:31:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; bh=AiwsPqpLajDblmfwVZFmm4G9n6taFlr90WZyacFgnmw=; b=FSZCQVBSbSlI7725sM1i7q4945jGTSRMqkt95NspbxZE274hxxSrIRC4szJvY6uqN7 gx64/tqrGOJVHcrCqNQcZttCn16p0eQjzs0J52v9jUXcMddlRmF2qyDHdnrMNPedNltu neak7zChqv8Y9gbpGnu0GkQEkPLpIRcxWyMuon3zSHQ9br/J8Gyxwcqd7HLr5lK9TbUx Z/u+5zzWm4acvV6BgRuFejd5YWgtH6R5pWt5mrn51jwOqPHkpZSP/M1SaHY4G9EMTOXj dtIgPkPLXlMMbVYsUjWscBfd99sUoZmwQ830xQ9cc0HMPpJu8jbGrEI9uwULFWf5h6P0 CSPA== MIME-Version: 1.0 Received: by 10.112.82.165 with SMTP id j5mr6930928lby.50.1343748693354; Tue, 31 Jul 2012 08:31:33 -0700 (PDT) Received: by 10.114.37.74 with HTTP; Tue, 31 Jul 2012 08:31:33 -0700 (PDT) In-Reply-To: References: Date: Tue, 31 Jul 2012 08:31:33 -0700 Message-ID: From: Freddie Cash To: =?UTF-8?Q?Karli_Sj=C3=B6berg?= Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Cc: "freebsd-fs@freebsd.org" Subject: Re: Hang when importing pool X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 31 Jul 2012 15:31:35 -0000 On Mon, Jul 30, 2012 at 11:31 PM, Karli Sj=C3=B6berg = wrote: > I=C2=B4m really struggling with this. I have had a pool with imported fil= esystems from a Solaris system that had dedup activated. Then, when the tim= e came to erase them, it just stalled. When rebooting, it stalled again at = mounting filesystems, and since then, I=C2=B4ve installed two USB drives to= act as root pool with FreeBSD-9.0-RELEASE so that I could import the origi= nal pool in recovery, but it always stalls after a couple of hours. Looking= at top, I could see that the 16GB RAM was maxed out, so I have heavily tun= ed down kmem, arc, etc: You're running out of RAM during the import, as it loads the DDT. Stuff a bunch more RAM into the machine (32 GB, 48 GB, even 64 GB). Then you will be able to load the full DDT into RAM, finish the aborted destroy process, and import the pool. We've run into this three or four times now on systems with dedupe enabled and only 16 GB of RAM. We've since upgraded all our boxes to a minimum of 32 GB, with one having 64 GB. ZFS dataset destruction with dedupe enabled takes *a lot* of time and RAM, as the DDT needs to be updated for every block freed. And rebooting in the middle of a "zfs destroy" operation means that the operation needs to finish at pool import time. --=20 Freddie Cash fjwcash@gmail.com