From owner-freebsd-hackers@FreeBSD.ORG Wed Oct 8 17:15:26 2008 Return-Path: Delivered-To: hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 709F4106568D for ; Wed, 8 Oct 2008 17:15:26 +0000 (UTC) (envelope-from zbeeble@gmail.com) Received: from mail-gx0-f21.google.com (mail-gx0-f21.google.com [209.85.217.21]) by mx1.freebsd.org (Postfix) with ESMTP id 076328FC14 for ; Wed, 8 Oct 2008 17:15:25 +0000 (UTC) (envelope-from zbeeble@gmail.com) Received: by gxk14 with SMTP id 14so8244102gxk.19 for ; Wed, 08 Oct 2008 10:15:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:date:from:to :subject:cc:in-reply-to:mime-version:content-type:references; bh=yy4EaRJhIOVySRlTgUeGSvfaLlKa0tHgfM3Sx6l4qsY=; b=sB6gFAnmev9FsN8R/I/Dx5HQTWze0aSpDaXB05+Ge70KEO3tB1TJkU0T7Iki8TDI8s AblGklTfZExjTZieFbiIfrhUBg0klNlQG+MV4ZTKGGk1/lI7CiyYGahEc3fxkfKQD5EF HLPdlcDxZ86yS3eRzgPD4iagASXJLucnhHQSY= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:cc:in-reply-to:mime-version :content-type:references; b=nxiM7kyMy9yiRXV72ALTcslTwwaad4FIrESfzzxwixVWupUeURYdKEKT4bHgz9xxPe QFZxJx5icVC9ZZPpqNeJp0jpzDu03+KSsJcFvESOHdKOqEpE349IdgsvmQiIvHVDWqLf gYdxVCVlDSriw7J2UPFei+4vVxRO770FBRGCE= Received: by 10.150.177.20 with SMTP id z20mr11873433ybe.192.1223486123179; Wed, 08 Oct 2008 10:15:23 -0700 (PDT) Received: by 10.150.137.11 with HTTP; Wed, 8 Oct 2008 10:15:23 -0700 (PDT) Message-ID: <5f67a8c40810081015p2c14e38evbeed0a97242a7c4a@mail.gmail.com> Date: Wed, 8 Oct 2008 13:15:23 -0400 From: "Zaphod Beeblebrox" To: "=?ISO-8859-1?Q?Dag-Erling_Sm=F8rgrav?=" In-Reply-To: <86iqs3sdtp.fsf@ds4.des.no> MIME-Version: 1.0 References: <48E9E1BB.6020908@ispro.net> <48EA56BB.6040702@vwsoft.com> <48EA8B3A.3090609@ispro.net> <861vysiv9i.fsf@ds4.des.no> <5f67a8c40810070937r5ba89773ncee407ace25fa0dd@mail.gmail.com> <86iqs3sdtp.fsf@ds4.des.no> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline X-Content-Filtered-By: Mailman/MimeDel 2.1.5 Cc: Volker , Evren Yurtesen , hackers@freebsd.org Subject: Re: continuous backup solution for FreeBSD X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 08 Oct 2008 17:15:26 -0000 On Wed, Oct 8, 2008 at 4:14 AM, Dag-Erling Sm=F8rgrav wrote: > "Zaphod Beeblebrox" writes: > > "Dag-Erling Sm=F8rgrav" writes: > > > What really annoys me with this thread is that nobody has provided > > > any information at all that would allow someone to understand what > > > needs to be done and estimate how hard it would be. > > Well... I hinted that a hammer port would be sufficient (although they > > need to finish their replication design) and I hinted that the hammer > > approach may be graftable to ZFS. Both reasonably large effort-wise > > (but probably within the scope of a single developer with sufficient > > time). > > No... you're so far off the mark it's not even funny, especially when > it's been repeatedly pointed out to you. This is not a file system, > it's a backup system. It's not designed to survive a disk crash or an > accidental file deletion, it's designed to survive a direct missile > strike on your colo center. > > To quote Wikipedia, "CDP is a service that captures changes to data to a > separate storage location" - emphasis on "separate". Wow... thanks for the flame, but there's no reason that the device that is receiving the hammer replication couldn't be on the other side of the globe and there's no reason it couldn't be considered a backup. Part of the advantage of the structure that allows you to efficiently select for new changes allows you to do the same kind of *backup* as they claim.