From owner-freebsd-current@freebsd.org Tue Dec 26 17:05:21 2017 Return-Path: Delivered-To: freebsd-current@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 283A5EA2B06 for ; Tue, 26 Dec 2017 17:05:21 +0000 (UTC) (envelope-from ohartmann@walstatt.org) Received: from mout.gmx.net (mout.gmx.net [212.227.17.20]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "mout.gmx.net", Issuer "TeleSec ServerPass DE-2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 96C947E81D; Tue, 26 Dec 2017 17:05:20 +0000 (UTC) (envelope-from ohartmann@walstatt.org) Received: from thor.intern.walstatt.dynvpn.de ([78.55.225.232]) by mail.gmx.com (mrgmx101 [212.227.17.168]) with ESMTPSA (Nemesis) id 0MOBOi-1eZOyf34TM-005ZPQ; Tue, 26 Dec 2017 18:05:17 +0100 Date: Tue, 26 Dec 2017 18:04:44 +0100 From: "O. Hartmann" To: Allan Jude Cc: freebsd-current@freebsd.org Subject: Re: ZFS: alignment/boundary for partition type freebsd-zfs Message-ID: <20171226180511.4d7d422e@thor.intern.walstatt.dynvpn.de> In-Reply-To: References: <20171226172521.611a89b0@thor.intern.walstatt.dynvpn.de> Organization: WALSTATT User-Agent: OutScare 3.1415926 X-Operating-System: ImNotAnOperatingSystem 3.141592527 MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; boundary="Sig_/GflVNx9FQAYEcP..BDCX8zP"; protocol="application/pgp-signature" X-Provags-ID: V03:K0:25AvfdidlJURc46YfdC4SDF14N5JcxjkYwl5hIzhViWTQ8Mq3sA 2I/bdfi8eNxuscupzjtlHkKBk1wqMc51cQ2SVzwrrKn3qOWBG5duaiVVUNKXliXrow0yoFt e2yyFSoqqJep/mAc/0AF25MlcWqqQ+Iq6ksX/liYz3DZW1XFyWfgCqU1MSjmTu2nDpcZ9Md 6jxz6LKEFr6kdMXs5JSeA== X-UI-Out-Filterresults: notjunk:1;V01:K0:i/BaTaLp3v0=:aN71KENyeY6G+fTdt9NMFE Q45pqdXDN6iFb3m6KaRX2JeUdgrdIm29zXvWPOlzsNGnIOV7ILuYxNd0MqIOd7q+Klw4ann7g YWON+uMGyy8oSto6oTN/ASDr7RhL9XFPQCOQFkqDfIFPWQbMZ39nNKaDylzG+exiu1ZHoHxfQ r4JyVbh7GA+86rhzdckno24sKbKkpf/sRoaJ0sZABoCT9SkvcolGtw38YhJ7W/CU8zReHKAMC HDnvcEebj817OZHvjR7hcIiZmFsX+5yMvjJI9/EKR5pGhKBIfGjTTj4ljI8Rw5IUVx0InbUiH Jzki70IDyzEhHfgN5FIhoanfhpewtZ4+fV3wbnX0ftyceDbbVmtorkEULDWaQuRn5SbczuunC 4RpcYdE/Cp6qD8zntYjIO3mmWDgUCMQig+J9TYBuFWyzAvSwRTotL+qdSeBS8BYlraeAIgztg O761Bk2mezyaWs/TQUBUhlZvEJ1MMYjoTqIx6vNa086RftTLhH5NDWO6MGn1KJsksvz5XM6yD NBaAy6ApVWhIKSc1LQPjPCMrBIKbWb/BYL6CtbM58X9bswDx6ziclEME2LGLDh7webAFKktzq bnRFgAUcyLA78JhX3Emw044l3b0AaPRJFd/cObv7qmAMLwaEGDwdApqpoc9N2mQ/c0FfMJ19a AvxlqI+v3zkSJZdLLctCDtEBP224UAtORNI9tUxzIW2/PSuXYljj1on5YACuSk22+kCiY/1Xn FP9NjsaGmRm6h42h4c1RBpDSXe/uNTDFHEH4nmgoDcUowffVJvlkw8MMYIz3fQ0nqxQJtuANz JoLi6XhqRZRHX5rh3O91pLiF44AVQ== X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.25 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: Tue, 26 Dec 2017 17:05:21 -0000 --Sig_/GflVNx9FQAYEcP..BDCX8zP Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Am Tue, 26 Dec 2017 11:44:29 -0500 Allan Jude schrieb: > On 2017-12-26 11:24, O. Hartmann wrote: > > Running recent CURRENT on most of our lab's boxes, I was in need to rep= lace and > > restore a ZFS RAIDZ pool. Doing so, I was in need to partition the disk= s I was about > > to replace. Well, the drives in question are 4k block size drives with = 512b emulation > > - as most of them today. I've created the only and sole partiton on eac= h 4 TB drive > > via the command sequence > >=20 > > gpart create -s GPT adaX > > gpart add -t freebsd-zfs -a 4k -l nameXX adaX > >=20 > > After doing this on all drives I was about to replace, something drove = me to check on > > the net and I found a lot of websites giving "advices", how to prepare = large, modern > > drives for ZFS. I think the GNOP trick is not necessary any more, but m= any blogs > > recommend to perform > >=20 > > gpart add -t freebsd-zfs -b 1m -a 4k -l nameXX adaX > >=20 > > to put the partition boundary at the 1 Megabytes boundary. I didn't do = that. My > > partitions all start now at block 40. > >=20 > > My question is: will this have severe performance consequences or is th= at negligible? > >=20 > > Since most of those websites I found via "zfs freebsd alignement" are f= rom years ago, > > I'm a bit confused now an consideration performing all this days-taking= resilvering > > process let me loose some more hair as the usual "fallout" ... > >=20 > > Thanks in advance, > >=20 > > Oliver > > =20 >=20 > The 1mb alignment is not required. It is just what I do to leave room > for the other partition types before the ZFS partition. >=20 > However, the replacement for the GNOP hack, is separate. In addition to > aligning the partitions to 4k, you have to tell ZFS that the drive is 4k: >=20 > sysctl vfs.zfs.min_auto_ashift=3D12 >=20 > (2^12 =3D 4096) >=20 > Before you create the pool, or add additional vdevs. >=20 I didn't do the sysctl vfs.zfs.min_auto_ashift=3D12 :-(( when I created the= vdev. What is the consequence for that for the pool? I lived under the impression that th= is is necessary for "native 4k" drives. How can I check what ashift is in effect for a specific vdev? --=20 O. Hartmann Ich widerspreche der Nutzung oder =C3=9Cbermittlung meiner Daten f=C3=BCr Werbezwecke oder f=C3=BCr die Markt- oder Meinungsforschung (=C2=A7 28 Abs.= 4 BDSG). --Sig_/GflVNx9FQAYEcP..BDCX8zP Content-Type: application/pgp-signature Content-Description: OpenPGP digital signature -----BEGIN PGP SIGNATURE----- iLUEARMKAB0WIQQZVZMzAtwC2T/86TrS528fyFhYlAUCWkKBRwAKCRDS528fyFhY lNE/AgCP/mI7TEfhdTPDYjVAny5DGWXylgPb4BpzzPcYSWBOAg+2nIdT9ySrwIq2 pLtsY9iAUqb9mmNDEVnn7LAkSQ0DAf9OdpNlKh+bcU8SAsmxNflih9NScl8djrdb 7Hsc1MFS1crG8Wwvwv8KFpZnfcPAyB6AjV3M4hKYNb+DwduO61Fu =gHOZ -----END PGP SIGNATURE----- --Sig_/GflVNx9FQAYEcP..BDCX8zP--