From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1B275C433DF for ; Mon, 25 May 2020 07:02:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E8491206DD for ; Mon, 25 May 2020 07:02:54 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Nk53v7n9" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388934AbgEYHCy (ORCPT ); Mon, 25 May 2020 03:02:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32834 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388385AbgEYHCy (ORCPT ); Mon, 25 May 2020 03:02:54 -0400 Received: from mail-io1-xd42.google.com (mail-io1-xd42.google.com [IPv6:2607:f8b0:4864:20::d42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E88A0C061A0E for ; Mon, 25 May 2020 00:02:53 -0700 (PDT) Received: by mail-io1-xd42.google.com with SMTP id d7so17721740ioq.5 for ; Mon, 25 May 2020 00:02:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=7+iOOw/QgAxLsV68rqYZ9eEavEEmLiM3PxzBIfCvL3Y=; b=Nk53v7n9XhZ6f8aXEPvl+q8ekmQPGy1P71wg7iCQE7SdOGLlFT2aozVvPfzBfhXL+w 6rS0eRSKOKT5CydHgI8maYfuK6YvBrAvUW9PpmDCh+3w57nEdCJMUpTCQrKfy3xVxbI0 KSTAoKQyFrFK7tFzEMGFsYc0E1p7cJiywGLqdxEmDWCG6u88vcs3Z9TTVN/sdsqFfASi gRmjVSnxStvnAwlMrewNtq3YyFxDVEB3MCv2l4rMtbLgm/Kn/NH3WH7sogc5CAZcSNBg lSuMqkwJa9RF3pfjI+iguQPBTchPldzTAgs7D72iYQH6RKU272OP0RHyoQUmDPzaTI5W 881Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=7+iOOw/QgAxLsV68rqYZ9eEavEEmLiM3PxzBIfCvL3Y=; b=glRJbttQ3CevffKk2Tv3LD7+BFkFgkTq0ehwVmWsxZzdK/e4JF6JKO+l7Sv710q/kq za6yv5xXF5tIfR7TthsW4e3ksz3aG1voqKcOqS/Jj0zAW4eOkzheUSjJaK8z2ZN3izXT Jw0lXP43a4U7mXIbNR1Jz4YdO6bwX2qi3aX/j4xI+5Y5sEDGeYrFKsxoNRFP1/a26Hp5 zNvB1roPAvBmZqDnuGv6Tyn82hRh6n1oU+CI8ueIU+cniNkiIToboRNy+XG1WAx6JZCU 23BubFCoZxjDVhBdR/p7ZntIQSIXnzarMTqxWvuAwmmSAWPUnKEaVeFeP8b9xFKnDf5L ut5A== X-Gm-Message-State: AOAM532UTpzxfHHwMqr3dKR97XjUSh8sWlUnElqTGzjVyuQgJlj29FVr jbom4IlvMppUTMVnAGNfpwhJ/5Xo9vrv10E1p14= X-Google-Smtp-Source: ABdhPJxNPqg16Oaz2ZvHJTrRIMnlr5UI/OO2eo8qNp7Zd0G7apZhCE6nXSzv/2lySKVOAACcBPHV7GUs29wQMNp9Hg8= X-Received: by 2002:a05:6602:2437:: with SMTP id g23mr3421370iob.5.1590390173228; Mon, 25 May 2020 00:02:53 -0700 (PDT) MIME-Version: 1.0 References: <20200513023618.GA2040@dread.disaster.area> <20200519062338.GH17627@magnolia> <20200520011430.GS2040@dread.disaster.area> <20200520151510.11837539@harpe.intellique.com> <20200525032354.GV2040@dread.disaster.area> <20200525060804.GC252930@magnolia> In-Reply-To: <20200525060804.GC252930@magnolia> From: Amir Goldstein Date: Mon, 25 May 2020 10:02:42 +0300 Message-ID: Subject: Re: [XFS SUMMIT] Deprecating V4 on-disk format To: "Darrick J. Wong" Cc: Dave Chinner , Emmanuel Florac , linux-xfs Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Sender: linux-xfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org On Mon, May 25, 2020 at 9:12 AM Darrick J. Wong w= rote: > > On Mon, May 25, 2020 at 01:23:54PM +1000, Dave Chinner wrote: > > On Wed, May 20, 2020 at 03:15:10PM +0200, Emmanuel Florac wrote: > > > Le Wed, 20 May 2020 11:14:30 +1000 > > > Dave Chinner =C3=A9crivait: > > > > > > > Well, there's a difference between what a distro that heavily > > > > patches the upstream kernel is willing to support and what upstream > > > > supports. And, realistically, v4 is going to be around for at least > > > > one more major distro release, which means the distro support time > > > > window is still going to be in the order of 15 years. > > > > > > IIRC, RedHat/CentOS v.7.x shipped with a v5-capable mkfs.xfs, but > > > defaulted to v4. That means that unless you were extremely cautious > > > (like I am :) 99% of RH/COs v7 will be running v4 volumes for the > > > coming years. How many years, would you ask? > > > > Largely irrelevant to the question at hand, as support is dependent > > on the distro lifecycle here. Essentially whatever is in RHEL7 is > > supported by RH until the end of it's life. > > > > In RHEL8, we default to v5 filesystems, but fully support v4. That > > will be the case for the rest of it's life. Unless the user > > specifically asks for it, no new v4 filesystems are being created on > > current RHEL releases. > > > > If we were to deprecate v4 now, then it will be marked as deprecated > > in the next major RHEL release. That means it's still fully > > supported in that release for it's entire life, but it will be > > removed in the next major release after that. So we are still > > talking about at least 15+ years of enterprise distro support for > > the format, even if upstream drops it sooner... > > We probably ought to do it sooner than later though, particularly if we > think/care about 5.9 turning into an LTS. > > > > As for the lifecycle of a filesystem, I just ended support on a 40 TB > > > archival server I set up back in 2007. I still have a number of > > > supported systems from the years 2008-2010, and about a hundred from > > > 2010-2013. That's how reliable XFS is, unfortunately :) > > > > Yup, 10-15 years is pretty much the expected max life of storage > > systems before the hardware really needs to be retired. We made v5 > > the default 5 years ago, so give it another 10 years (the sort of > > timeframe we are talking about here) and just about > > everything will be running v5 and that's when v4 can likely be > > dropped. > > > > The other thing to consider is that we need to drop v4 before we get > > to y2038 support issues as the format will never support dates > > beyond that. Essentially, we need to have the deprecation discussion > > and take action in the near future so that people have stopped using > > it before y2038 comes along and v4 filesystems break everything. > > > > Not enough people think long term when it comes to computers - it > > should be more obvious now why I brought this up for discussion... > > Ok then, who would like to help me get the y2038 timestamp patches > reviewed for ~5.9? :D > I can help with review. Already looked at your branch. Thanks, Amir.