From owner-freebsd-fs@FreeBSD.ORG Wed Aug 8 15:55:15 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 D1DBB1065670 for ; Wed, 8 Aug 2012 15:55:15 +0000 (UTC) (envelope-from ndenev@gmail.com) Received: from mail-ee0-f54.google.com (mail-ee0-f54.google.com [74.125.83.54]) by mx1.freebsd.org (Postfix) with ESMTP id 5DF938FC17 for ; Wed, 8 Aug 2012 15:55:15 +0000 (UTC) Received: by eeke52 with SMTP id e52so310271eek.13 for ; Wed, 08 Aug 2012 08:55:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=subject:mime-version:content-type:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to:x-mailer; bh=QP4qft1ypxwnqECzseUp3i49V/7CldhO1qmBt5CtReo=; b=UdG1Vmiso17TKt1EYsE2GwJkuUJwZxwwxsBrn9H7Yy57zuy3fJlefa1g0SFCx18E3H mV6nSBO0F8omdAYVyevxCZ3F6NDCu+Y4zEIvtWRii03DuDryaWXA2ackABKkfgWEnvhD bc6o+HR9mRST/ekcyy9zgbDt1zW8+YG8Ly9rjOzdfRjX4TZYf5jvk08a88EcE8z5yrGW fIoc7VkW3W8nphAppWLhjTWwQ4lT+acVxZoNSwbSkn5lcXKT9N9dgk2Wn0d/fAGVvcYA 5IQaMdsg3AorhNF+VPelUsdF9L9kVJQv7yO6uumUgguDz+3aYkPhk25BUQnr9xUANYhw EkQw== Received: by 10.14.173.71 with SMTP id u47mr450049eel.22.1344441314337; Wed, 08 Aug 2012 08:55:14 -0700 (PDT) Received: from imba-brutale.totalterror.net ([93.152.184.10]) by mx.google.com with ESMTPS id e7sm29632708eep.2.2012.08.08.08.55.12 (version=TLSv1/SSLv3 cipher=OTHER); Wed, 08 Aug 2012 08:55:13 -0700 (PDT) Mime-Version: 1.0 (Mac OS X Mail 6.0 \(1485\)) Content-Type: text/plain; charset=us-ascii From: Nikolay Denev In-Reply-To: <0c8801cd757a$601018e0$20304aa0$@simons-rock.edu> Date: Wed, 8 Aug 2012 18:55:14 +0300 Content-Transfer-Encoding: quoted-printable Message-Id: <63850C98-E472-40B9-8E7F-93FD6AC6B95E@gmail.com> References: <0c8801cd757a$601018e0$20304aa0$@simons-rock.edu> To: Brian Gold X-Mailer: Apple Mail (2.1485) Cc: freebsd-fs@freebsd.org Subject: Re: undoing zfs deduplication 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: Wed, 08 Aug 2012 15:55:15 -0000 On Aug 8, 2012, at 6:27 PM, Brian Gold wrote: > I've got a system running 9.0-release w/ a zfs v28 pool. Within that = pool I have 3 datasets, two of which have deduplication > enabled. I've recently been having a lot of performance issues with = deduplication and have determined that I need far more ram that > I currently have in order to support dedupe. I don't have the budget = for the ram necessary so I would like to move away from > deduplication. I'm aware that you can't simply turn dedupe off, you = need to completely nuke the filesystem.=20 >=20 > What I'm wondering is, would it be possible for me to create new = datasets within the same pool (I have a ton of available space) and > use a combination of "zfs send" & "zfs receive" to migrate my deduped = datasets and all of their snapshots (daily, weekly, & monthly) > over to the new dataset?=20 >=20 > Brian Gold > System Administrator > Bard College at Simon's Rock >=20 >=20 >=20 > _______________________________________________ > freebsd-fs@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-fs > To unsubscribe, send any mail to "freebsd-fs-unsubscribe@freebsd.org" I believe simply disabling dedup should be enough. Some blocks still will be just a "reference" to the original block = because of the previously enabled deduplication, but this won't use = additional memory. New files will be written without being deduped. If you want to de-dedup the files you can probably just "rsync $source = $source.tmp && mv $source.tmp $source" in a loop to rewrite them.=