From owner-freebsd-fs@freebsd.org Mon Aug 10 11:38:24 2015 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 C0E7E99EDCF for ; Mon, 10 Aug 2015 11:38:24 +0000 (UTC) (envelope-from wjw@digiware.nl) Received: from smtp.digiware.nl (smtp.digiware.nl [31.223.170.169]) (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 822131FF for ; Mon, 10 Aug 2015 11:38:24 +0000 (UTC) (envelope-from wjw@digiware.nl) Received: from rack1.digiware.nl (unknown [127.0.0.1]) by smtp.digiware.nl (Postfix) with ESMTP id 4BCBB153466; Mon, 10 Aug 2015 13:38:15 +0200 (CEST) X-Virus-Scanned: amavisd-new at digiware.nl Received: from smtp.digiware.nl ([127.0.0.1]) by rack1.digiware.nl (rack1.digiware.nl [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id BU_McFat9Nk2; Mon, 10 Aug 2015 13:37:56 +0200 (CEST) Received: from [IPv6:2001:4cb8:3:1:21eb:d0a9:8ec7:27cb] (unknown [IPv6:2001:4cb8:3:1:21eb:d0a9:8ec7:27cb]) by smtp.digiware.nl (Postfix) with ESMTP id 4CFD7153401; Mon, 10 Aug 2015 13:37:56 +0200 (CEST) Message-ID: <55C88D16.8090700@digiware.nl> Date: Mon, 10 Aug 2015 13:37:58 +0200 From: Willem Jan Withagen Organization: Digiware Management b.v. User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 To: Fabian Keil CC: freebsd-fs@freebsd.org Subject: Re: Urgently need some help solving lost space due to snapshots during receive op References: <55C82BCD.2050404@herveybayaustralia.com.au> <55C863DE.3000200@digiware.nl> <60563a3f.3d0a7128@fabiankeil.de> In-Reply-To: <60563a3f.3d0a7128@fabiankeil.de> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 10 Aug 2015 11:38:24 -0000 On 10-8-2015 12:34, Fabian Keil wrote: > Willem Jan Withagen wrote: > >> On 10-8-2015 06:42, Da Rock wrote: >>> I'm trying to move a pool from one system to another - exact same hdd >>> and config, different in other areas. Both register same space >>> available, and so should be no issue. The old system is quite full - >>> still at least 5% free though. > >> Are the versions of your FreeBSD also equal? >> >> Because in newer version, the free space reservation is significantly >> bigger. So if disks are equal size, then with newer FreeBSDs you have >> less usable space available. >> Don't know the exact SVN commit where it happened. But there are more >> question on this topic in the list, and they all boil down to the same >> thing: ZFS needs more reserved space to be able to do certain things >> without freezing the system. >> >> I've not read any suggestions that you can circumvent this setting. > > You can increase the usable space by increasing vfs.zfs.spa_slop_shift: > > fk@r500 ~ $sysctl vfs.zfs.spa_slop_shift > vfs.zfs.spa_slop_shift: 6 > fk@r500 ~ $zfs list tank > NAME USED AVAIL REFER MOUNTPOINT > tank 190G 34.4G 136K /tank > fk@r500 ~ $sudo sysctl vfs.zfs.spa_slop_shift=7 > vfs.zfs.spa_slop_shift: 6 -> 7 > fk@r500 ~ $zfs list tank > NAME USED AVAIL REFER MOUNTPOINT > tank 190G 36.2G 136K /tank Ah, Really nice info... Bet that that is going to "rescue" some of the migrating ZFS users. --WjW