From owner-freebsd-fs@FreeBSD.ORG Tue Feb 24 17:52:59 2015 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 4AB144A2 for ; Tue, 24 Feb 2015 17:52:59 +0000 (UTC) Received: from mail-wi0-f175.google.com (mail-wi0-f175.google.com [209.85.212.175]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id D5A7BD9E for ; Tue, 24 Feb 2015 17:52:58 +0000 (UTC) Received: by mail-wi0-f175.google.com with SMTP id r20so27494035wiv.2 for ; Tue, 24 Feb 2015 09:52:50 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:message-id:date:from:user-agent:mime-version:to :subject:references:in-reply-to:content-type :content-transfer-encoding; bh=hjeCOwg5/vpCanpwx52u0ED/wvt3aj8C4F9q5DWYUPA=; b=LnPBC9xk7BWPzTRRLf3NbcOEPDXNLHGBNWqkyxRpyn8MemEaW79PGSN+5mbWlED+Ph jAmhnpe2FWOOOgyxZ0lM4PsZLXaVCErRGv+Le4aH313gNA1vdw9XwxggfhGYgVa9r6Ig en3ATfRD5qPV59zhVJ7Si2QCodd6g49vvZkVjcXM2y1xXRCaB1IZgyn5O5LjMndh/J/s UmxP4XHOKoTxeds09Lc5DpJEJkXqoh+LllRdtEC82E/QLGYDxAwPAvh52X8YP72RcYZ7 3SN/HwkNjTfHwsHalYnZ3vQJPk1OUJpK8pEyhPSXjBbgC3j4WAqx9R3RuiXqHk/sFQOR Ggww== X-Gm-Message-State: ALoCoQmFLJmhJYuW0LJNb76Xp6+5ft+aFOSoMYyiW52UBuquokJbLEJGQ0Nc+mG7CNxW+YSwsqng X-Received: by 10.194.178.161 with SMTP id cz1mr35508636wjc.102.1424799889404; Tue, 24 Feb 2015 09:44:49 -0800 (PST) Received: from [10.10.1.68] (82-69-141-170.dsl.in-addr.zen.co.uk. [82.69.141.170]) by mx.google.com with ESMTPSA id bd3sm13928499wib.17.2015.02.24.09.44.48 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 24 Feb 2015 09:44:48 -0800 (PST) Message-ID: <54ECB88C.5060305@multiplay.co.uk> Date: Tue, 24 Feb 2015 17:44:44 +0000 From: Steven Hartland User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:31.0) Gecko/20100101 Thunderbird/31.4.0 MIME-Version: 1.0 To: freebsd-fs@freebsd.org Subject: Re: Proposal: enhancing zfs hold, atomic holds on create, snap and receive References: In-Reply-To: Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 8bit X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 24 Feb 2015 17:52:59 -0000 Bookmarks? On 24/02/2015 16:38, Borja Marcos wrote: > Hi :) > > I''ve been doing some incremental replication work with ZFS, and I am using holds to prevent user errors. > When someone destroys the wrong snapshot, a dataset must be sent wholly beacuse it's no longer > possible to perform an incremental send. A hold can prevent it, marking the snapshot as "critical for incremental > replication". Of course holds are even better as you can assign several labelled holds > to a single snapshot, so that each hold can represent a different reason to keep it. > > But there's a missing feature which would make them as perfect as they can get: holds > are somewhat of an afterthough, a second class citizen compared to properties and, unlike properties, > you can't (for example) place a hold atomically on a snapshot when creating it. > > ZFS has a nice feature that allows you to create an object (snapshot or dataset) and, *atomically* assign a property to it. > The same feature applies to create and clone, of course, although it doesn´t to receive, which might be useful. > > So, the proposal is to add a "-h hold1,hold2,..holdN" option to "zfs snap" and ideally zfs receive, so that a hold would be > placed atomically with the snapshot creation. > > This feature would prevent some possible race conditions in snapshot management, which would make them much more useful. > I imagine that the -o option as added with the same purpose. > > What do you think? > > > Thanks! > > > > > Borja. > _______________________________________________ > 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"