From owner-freebsd-fs@FreeBSD.ORG Wed Mar 24 18:07:58 2010 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 A06F2106564A; Wed, 24 Mar 2010 18:07:58 +0000 (UTC) (envelope-from delphij@gmail.com) Received: from mail-px0-f200.google.com (mail-px0-f200.google.com [209.85.216.200]) by mx1.freebsd.org (Postfix) with ESMTP id 6F76F8FC12; Wed, 24 Mar 2010 18:07:58 +0000 (UTC) Received: by pxi38 with SMTP id 38so4631608pxi.27 for ; Wed, 24 Mar 2010 11:07:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:message-id:subject:from:to:cc:content-type :content-transfer-encoding; bh=evEPG31T6Tiqd3UM1fCe5RgJXJUIX6P8v0uSeAK8/d0=; b=OJEm8Rwhx0cXS+2RSvXZVics1uborksN9UnXZLDGBOk+HIREErAdPNNVtXpQHBAyH9 k7rmPisA5JOZsaF7Ogl9oRIG2VLeQLLkIInMDz/2iTgYk3GL6rFCF/M6KcJdqfMYCz6X t4yNP1yZd8oXdiMnO0pepwhU47QSyxqn6yfPc= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=Y3LPwJP10s1r1xDLoNFmm5WBTpo/ryu/7FkSJVXlrNtgHsz0a5nEPJqcpiTb2IT3G+ zsYyWFdf3R+PBJWon/bKEHdFSUcKfvb8KR4X5tW029RX2irHy4sqD22AQdR7CdDt1Eg8 1qc3PjEugajfFYr3RgHhh8vLG65bqLtKE5jPs= MIME-Version: 1.0 Received: by 10.142.248.11 with SMTP id v11mr240976wfh.22.1269454077681; Wed, 24 Mar 2010 11:07:57 -0700 (PDT) In-Reply-To: <2FF0A3E3-AF2F-4674-8648-FC01EC87445E@mac.com> References: <4BAA3E25.9040108@icyb.net.ua> <2FF0A3E3-AF2F-4674-8648-FC01EC87445E@mac.com> Date: Wed, 24 Mar 2010 11:07:57 -0700 Message-ID: From: Xin LI To: Steve Pate Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Cc: freebsd-fs@freebsd.org, Pawel Jakub Dawidek , Andriy Gapon Subject: Re: ZFS and 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, 24 Mar 2010 18:07:58 -0000 Hi, Steve, On Wed, Mar 24, 2010 at 10:24 AM, Steve Pate wrote: > I'm really not familiar with the FreeBSD development process so I apologi= ze if I'm asking questions which appear naive. > > We'd like to ship a FreeBSD-based product by early next year that contain= s ZFS with de-dup. From what I see, FreeBSD seems to be tracking Solaris in= terms of taking stable versions of ZFS. In other words, you're taking the = version of ZFS that will next move from Open Solaris to Solaris. Is that co= rrect? > > >From what I understand FreeBSD 8-STABLE includes ZFS version 14, which b= rings it to parity with Solaris 10. > > ZFS version 21 contains de-duplication so is quite a long way ahead of wh= ere FreeBSD is today. This implies that it will take quite some time for ZF= S + de-dupe to get into a stable version of FreeBSD. Correct? > > Now, if we were to port ZFS version 22 (or later) to FreeBSD 8.x (version= number TBD), how could we work with the FreeBSD team to get ZFS version 21= + back into a subsequent FreeBSD release? Pawel is working on porting the -HEAD ZFS version from OpenSolaris right no= w. For FreeBSD 8.x I think there are some things that we need to take into consideration. OpenSolaris generally strives to keep API/ABI stability but for ZFS management tools like zfs(1m) and friends this does not apply, e.g., the ioctl request structure changes from time to time. In the past we broke ABI across ZFS v6 -> v13 update. This basically means one will have to update kernel and userland at the same time, which would make the upgrade an one-way ticket (otherwise it would be impossible to do operations like zpool import once kernel is upgraded and restarted). I think, if we plan to MFC it we need to make some compatibility shims instead of using the current approach. Cheers, --=20 Xin LI http://www.delphij.net