From owner-freebsd-performance@FreeBSD.ORG Fri Nov 18 12:22:21 2011 Return-Path: Delivered-To: freebsd-performance@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id F330E1065670 for ; Fri, 18 Nov 2011 12:22:21 +0000 (UTC) (envelope-from tevans.uk@googlemail.com) Received: from mail-vw0-f54.google.com (mail-vw0-f54.google.com [209.85.212.54]) by mx1.freebsd.org (Postfix) with ESMTP id B22318FC12 for ; Fri, 18 Nov 2011 12:22:21 +0000 (UTC) Received: by vbbfa15 with SMTP id fa15so209373vbb.13 for ; Fri, 18 Nov 2011 04:22:21 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlemail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; bh=x0IG38v6p1YOQwQUZ4sowN56bQ4CuHvZjLbQrCi8gpk=; b=rKEZFO6eISuMWQ4aC1NKodPvUrAK5ho2rbrUxv/K8WgUKufqWGaSs1+cIHwJ8fCX8Z 6Zj73+0rqppXJ102jFX9fg6yuJkF5KzVkQPRwnTTggH5ua3O0QjJSBNx41VXdGz+L0bH 7hUbcptEHygb241stQxaU+ZlWcg9Llp6HYCKU= MIME-Version: 1.0 Received: by 10.52.89.206 with SMTP id bq14mr3186083vdb.39.1321618940916; Fri, 18 Nov 2011 04:22:20 -0800 (PST) Received: by 10.52.182.40 with HTTP; Fri, 18 Nov 2011 04:22:20 -0800 (PST) In-Reply-To: <4ec63674.03d5960a.7701.58bfSMTPIN_ADDED@mx.google.com> References: <4ec60f6b.893a440a.4ce1.ffffa30dSMTPIN_ADDED@mx.google.com> <4ec63674.03d5960a.7701.58bfSMTPIN_ADDED@mx.google.com> Date: Fri, 18 Nov 2011 12:22:20 +0000 Message-ID: From: Tom Evans To: Eduardo Morras Content-Type: text/plain; charset=UTF-8 Cc: freebsd-performance@freebsd.org Subject: Re: ZFS Few Questions X-BeenThere: freebsd-performance@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Performance/tuning List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 18 Nov 2011 12:22:22 -0000 On Fri, Nov 18, 2011 at 10:40 AM, Eduardo Morras wrote: > I mean that surely db will be corrupted and nothing could be recovered. I > know postgresql and there you have a begin snapshot - end snapshot for this > topic, data changes are stored in temporal archives and main db files are > consistent, allowing you to make a filesystem snapshot. For mysql don't > know. You can do similar thing with MySQL - 'FLUSH TABLES WITH READ LOCK', zfs snapshot, release lock, job done. It's not as good as postgresql, which doesn't require the tables to be locked for writes. I would imagine as ZFS and MySQL are both owned by Oracle the situation will improve. Cheers Tom