From owner-freebsd-current@FreeBSD.ORG Sun Dec 7 11:35:12 2008 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id B19BA1065670 for ; Sun, 7 Dec 2008 11:35:12 +0000 (UTC) (envelope-from scode@hyperion.scode.org) Received: from hyperion.scode.org (cl-1361.ams-04.nl.sixxs.net [IPv6:2001:960:2:550::2]) by mx1.freebsd.org (Postfix) with ESMTP id 325828FC28 for ; Sun, 7 Dec 2008 11:35:12 +0000 (UTC) (envelope-from scode@hyperion.scode.org) Received: by hyperion.scode.org (Postfix, from userid 1001) id AD16B23C482; Sun, 7 Dec 2008 12:35:10 +0100 (CET) Date: Sun, 7 Dec 2008 12:35:10 +0100 From: Peter Schuller To: Marius =?iso-8859-1?Q?N=FCnnerich?= Message-ID: <20081207113509.GA19385@hyperion.scode.org> References: <20081117205526.GC1733@garage.freebsd.pl> <20081202203308.GA13818@hyperion.scode.org> <200812021254.21242.fjwcash@gmail.com> <20081202232924.GA19134@hyperion.scode.org> <31C70CBC-488A-4A9A-A642-37855E8F1DD1@lassitu.de> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="Nq2Wo0NMKNjxTN9z" Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.18 (2008-05-17) Cc: FreeBSD Current Subject: Re: HEADS UP: New ZFS in the tree. X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 07 Dec 2008 11:35:12 -0000 --Nq2Wo0NMKNjxTN9z Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable > While you are talking about it: Does anyone know if the fsync blocks > until the data is really stable on the device or if it simply returns > when ZIL is disabled? >=20 > In my understanding the topmost block would need to be written for the > "commit" to be on disk. My understanding is that disabling the ZIL *will* break the semantics of fsync(). The claim of "always consistent on disk" is not violated and is still maintained, since consistency refers to ZFS' internal consistency. The tuning guide someone posts a link to later in this thread has specific claims about this IIRC; such as NFS breaking (because fsync-on-close semantics mandated by NFS, among other things, will not be honored). --=20 / Peter Schuller PGP userID: 0xE9758B7D or 'Peter Schuller ' Key retrieval: Send an E-Mail to getpgpkey@scode.org E-Mail: peter.schuller@infidyne.com Web: http://www.scode.org --Nq2Wo0NMKNjxTN9z Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.9 (FreeBSD) iEYEARECAAYFAkk7tOwACgkQDNor2+l1i31wYQCeLkDSKHb1kfvO9ln6WRDD9vJP UFEAn1NzQ4lJadbEDsMmTh5ubK1krbYK =TciO -----END PGP SIGNATURE----- --Nq2Wo0NMKNjxTN9z--