From owner-freebsd-jail@freebsd.org Sun Dec 18 12:20:42 2016 Return-Path: Delivered-To: freebsd-jail@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 C2F91C719C4 for ; Sun, 18 Dec 2016 12:20:42 +0000 (UTC) (envelope-from 000.fbsd@quip.cz) Received: from elsa.codelab.cz (elsa.codelab.cz [94.124.105.4]) (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 7CD31192C for ; Sun, 18 Dec 2016 12:20:41 +0000 (UTC) (envelope-from 000.fbsd@quip.cz) Received: from elsa.codelab.cz (localhost [127.0.0.1]) by elsa.codelab.cz (Postfix) with ESMTP id 2885E28426; Sun, 18 Dec 2016 13:20:33 +0100 (CET) Received: from illbsd.quip.test (ip-86-49-16-209.net.upcbroadband.cz [86.49.16.209]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by elsa.codelab.cz (Postfix) with ESMTPSA id 1BAFB28417; Sun, 18 Dec 2016 13:20:32 +0100 (CET) Subject: Re: ZFS and Jail :: nullfs mount :: nothing visible from host :: solved [partial] To: Alexander Leidinger , SK Cc: freebsd-jail References: <584986D0.3040109@quip.cz> <2b6346f8-ed02-0e6d-bd89-106098e7eb2d@cps-intl.org> <58499446.3050403@quip.cz> <5849C5BF.7020005@quip.cz> <584A9179.9060508@quip.cz> <584A9D89.4040003@quip.cz> <3851c5d9-7646-b670-357e-ae937fcc7e8f@cps-intl.org> <584AB345.4080307@quip.cz> <33473585-3cb9-10d3-acf9-0a917c5a0079@cps-intl.org> <20161216141540.Horde.zfu3fokeVx7FuFkk7_s-nbW@webmail.leidinger.net> <20161217195949.Horde.PTQ3AH5YpaT79dVSxM5UvNr@webmail.leidinger.net> From: Miroslav Lachman <000.fbsd@quip.cz> Message-ID: <58567F0F.4010404@quip.cz> Date: Sun, 18 Dec 2016 13:20:31 +0100 User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:42.0) Gecko/20100101 Firefox/42.0 SeaMonkey/2.39 MIME-Version: 1.0 In-Reply-To: <20161217195949.Horde.PTQ3AH5YpaT79dVSxM5UvNr@webmail.leidinger.net> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-BeenThere: freebsd-jail@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: "Discussion about FreeBSD jail\(8\)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 18 Dec 2016 12:20:43 -0000 Alexander Leidinger wrote on 2016/12/17 19:59: > Quoting SK (from Fri, 16 Dec 2016 14:02:20 +0000): >> If I understand you correctly, what you are suggesting is, the dataset >> used by the jail itself for its root/base cannot be "worked on" from >> within the jail, but if I define a different dataset (under the same >> branch below the jail dataset), and attribute it to the jail, then I >> can manipulate that "other" dataset. Could you please confirm if I >> understood it correctly? > > Correct. > > You need the data in the root of the jail to boot, if you then attribute > this dataset to the jail, it will vanish until "zfs mount -a" is run (rc > script inside the jail). As it will vanish during the boot of the jail > (if added automatically), the rc script to mount all datasets can not be > found. [...] >> I think what you are trying to tell here is, unless and until that >> "vanished" dataset is put to use (mounted) from inside the jail, it >> will remain vanished/unusable from the host itself; however, once that >> dataset is put to use, the host system should be able to "see" and >> maybe even work on that dataset. Could you please confirm if I >> understood you correctly? > > Correct. > > A sub-dataset which is not needed to boot, or a dataset not within the > subtree of the jail (and not needed to boot) can be used. Thank you for this information! If it is somewhere in the docs it is well hidden to me :) Miroslav Lachman