From owner-freebsd-stable@FreeBSD.ORG Wed Jul 29 09:52:18 2009 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 4872E10656D4 for ; Wed, 29 Jul 2009 09:52:18 +0000 (UTC) (envelope-from arnaud.houdelette@tzim.net) Received: from golanth.tzim.net (unknown [IPv6:2001:41d0:1:d91f:21c:c0ff:fe4b:cf32]) by mx1.freebsd.org (Postfix) with ESMTP id DA0678FC15 for ; Wed, 29 Jul 2009 09:52:17 +0000 (UTC) (envelope-from arnaud.houdelette@tzim.net) Received: from alarante.irisa.fr ([131.254.13.244]) by golanth.tzim.net with esmtpsa (TLSv1:AES256-SHA:256) (Exim 4.69 (FreeBSD)) (envelope-from ) id 1MW5pY-0009ec-N5; Wed, 29 Jul 2009 11:52:16 +0200 Message-ID: <4A701BCB.4030805@tzim.net> Date: Wed, 29 Jul 2009 11:52:11 +0200 From: Arnaud Houdelette User-Agent: Thunderbird 2.0.0.21 (Macintosh/20090302) MIME-Version: 1.0 To: Mark Stapper References: <14989d6e0907290045j94bab06wb5d0114fe2af2331@mail.gmail.com> <4A7008F2.6090107@mapper.nl> In-Reply-To: <4A7008F2.6090107@mapper.nl> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-Authenticated-User: tzim@tzim.net X-Authenticator: plain Cc: FreeBSD Subject: Re: Cannot rm files when ZFS is full X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 29 Jul 2009 09:52:18 -0000 Mark Stapper a écrit : > Christian Walther wrote: > >> 2009/7/29 grarpamp : >> >> >>> One week old build... >>> >>> # df -i . >>> Filesystem 1K-blocks Used Avail Capacity iused ifree %iused Mounted on >>> ram01/mnt1 239465344 239465344 0 100% 13163 0 100% /mnt1 >>> # ls -aliT zero >>> 20797 -rw-r--r-- 1 user user 43515904 Jul 28 23:20:57 2009 zero >>> # rm -f zero >>> rm: zero: No space left on device >>> # :> zero >>> cannot create zero: File exists >>> # cp /dev/null zero >>> overwrite zero? (y/n [n]) y >>> # ls -aliT zero >>> 20797 -rw-rw-rw- 1 root wheel 0 Jul 28 23:25:17 2009 zero >>> # rm -f zero >>> [gone] >>> >>> >> this is a known problem with the current version of ZFS. Due to the >> way ZFS handles access to the data it stores, even a rm causes a >> write, which requires some additional disk space in the beginning: >> Instead of simply unlinking what should be removed ZFS creates another >> tree without the removed data. Only if this new tree has been entirely >> written to disk the old information is removed. This is a rather rough >> explanation and probably not entirely correct, but I hope it suffices. >> Only hope: Make sure that not all disk space is used. >> >> Christian >> >> > Indeed, if by some coincident (like a growing logfile) every single byte > is used, even the copy action might fail... > To prevent this you could set the maximum size of all partitions in your > pool so that the sum of them is smaller then the size of your pool. > Just a thought. > Greetz, > Mark > > Wouldn't that be counterproductive ? One avantage of ZFS is that you don't need to manage space, and that free space is shared. Setting size as this would reintroduce the hassle of free space management. Wouldn't the simplest be to set a reservation on an unused (or known as non-growing) filesystem, and/or quotas to filesystem susceptible of growing out of control ? Arnaud