From owner-freebsd-fs@freebsd.org Mon Feb 27 09:08:58 2017 Return-Path: Delivered-To: freebsd-fs@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 03748CEFD2A for ; Mon, 27 Feb 2017 09:08:58 +0000 (UTC) (envelope-from crest@rlwinm.de) Received: from smtp.rlwinm.de (smtp.rlwinm.de [IPv6:2a01:4f8:201:31ef::e]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id C559F62D for ; Mon, 27 Feb 2017 09:08:57 +0000 (UTC) (envelope-from crest@rlwinm.de) Received: from crest.lan.bultmann.eu (unknown [87.253.189.132]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.rlwinm.de (Postfix) with ESMTPSA id E73497544; Mon, 27 Feb 2017 10:08:54 +0100 (CET) Subject: Re: ufs2+su+journal-snapshots To: Sergey Matveychuk , freebsd-fs@freebsd.org References: From: Jan Bramkamp Message-ID: <83019546-b7a8-52cf-7fed-768874b50d42@rlwinm.de> Date: Mon, 27 Feb 2017 10:08:54 +0100 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.12; rv:45.0) Gecko/20100101 Thunderbird/45.7.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 27 Feb 2017 09:08:58 -0000 On 26/02/2017 19:59, Sergey Matveychuk wrote: > Hi. > > I know, it's an annoying question but is there a plan to fix snapshots > with journaling? May be any project to try and to test? > > Journal enabled in default install now and we lost snapshots (and > backups). It does ufs2 almost useless now. Sure, I can disable > journaling and back to 2000s but it's sadly. > > Many fellows has moved to ZFS and I did the same on a few servers but > often ZFS is overkill (and slow) for me. I'm just reporting hearsay from the last EuroBSDcon, but afaik there is nobody working on UFS with SU+J and Snapshots. The main problem is the interaction of the SU+J code and Snapshots across reboots. Apparently it would be a lot simpler to implement Snapshots that are lost at shutdown. This would be enough for dump -L and other backup tools. Disabling just the journaling part of the soft-updates isn't that bad for small file systems. It should even improve performance in most cases, but it requires a *background* fsck after an unclean shutdown. On small file systems this isn't a huge problem. It becomes a problem if either the ratio of bandwidth to capacity or the ratio of physical RAM to capacity become too large. In either case ZFS and (a bit) more RAM is the best solution available in FreeBSD.