From owner-freebsd-hackers@FreeBSD.ORG Sun Jun 1 01:16:53 2014 Return-Path: Delivered-To: hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 15664DF6 for ; Sun, 1 Jun 2014 01:16:53 +0000 (UTC) Received: from kib.kiev.ua (kib.kiev.ua [IPv6:2001:470:d5e7:1::1]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 756892E79 for ; Sun, 1 Jun 2014 01:16:52 +0000 (UTC) Received: from tom.home (kostik@localhost [127.0.0.1]) by kib.kiev.ua (8.14.9/8.14.9) with ESMTP id s511GjhF001394; Sun, 1 Jun 2014 04:16:45 +0300 (EEST) (envelope-from kostikbel@gmail.com) DKIM-Filter: OpenDKIM Filter v2.8.3 kib.kiev.ua s511GjhF001394 Received: (from kostik@localhost) by tom.home (8.14.9/8.14.8/Submit) id s511GjQK001393; Sun, 1 Jun 2014 04:16:45 +0300 (EEST) (envelope-from kostikbel@gmail.com) X-Authentication-Warning: tom.home: kostik set sender to kostikbel@gmail.com using -f Date: Sun, 1 Jun 2014 04:16:45 +0300 From: Konstantin Belousov To: "Michael W. Lucas" Subject: Re: fdisk(8) vs gpart(8), and gnop Message-ID: <20140601011645.GQ3991@kib.kiev.ua> References: <20140601004242.GA97224@bewilderbeast.blackhelicopters.org> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="ZRLamLUCLuRJXeX8" Content-Disposition: inline In-Reply-To: <20140601004242.GA97224@bewilderbeast.blackhelicopters.org> User-Agent: Mutt/1.5.23 (2014-03-12) X-Spam-Status: No, score=-2.0 required=5.0 tests=ALL_TRUSTED,BAYES_00, DKIM_ADSP_CUSTOM_MED,FREEMAIL_FROM,NML_ADSP_CUSTOM_MED autolearn=no autolearn_force=no version=3.4.0 X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on tom.home Cc: hackers@freebsd.org X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 01 Jun 2014 01:16:53 -0000 --ZRLamLUCLuRJXeX8 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Sat, May 31, 2014 at 08:42:42PM -0400, Michael W. Lucas wrote: > Finally, while UFS isn't picky about changing the underlying sector > size on a dump/restore, I believe it's a good idea to always gnop the > underlying disk. Disks lie about sector size, and while it's OK to > assume a 4k-sector disk, assuming a 512b-sector disk on a 4k-sector > disk causes write multiplication. >=20 > Are my beliefs correct? FFS never reads/writes less than the fragment size for the data or inode access. Default current setting for newfs is 4K fragment size. Earlier the fragment size was 2K, AFAIR, but this is irrelevant for the new disks, unless sector-to-sector copy is performed. FFS uses cg block size to access cylinder groups, which is definitely greater than 8K. --ZRLamLUCLuRJXeX8 Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.22 (FreeBSD) iQIcBAEBAgAGBQJTin78AAoJEJDCuSvBvK1BDDEP/0anwQWPalkAFeJDXWWxgOPg W6UVfCkh/Wj+zwYNIFeScoWTxrvXwCgcXx2aeA4WF6+hUeDmUxQDDI/2cFqskQ3M Rl6+YGskToxd80R/e+7YCRrPapUiXH/RnKhi4QOjSOjv41paW85f0yemlvezCchf hG5NVTo4NXu3/+udE7ks4AKlm019kcqrk8OxmFVNLzkDN8qjDcNE4wmVZX+lT6zc 1DOLlDIIkLxSLf3HC6CIUI1B9CxfQb/hh6yalm/k0gydEWCEOH13PQUGkpK8oSLj Jo+aKhr9Z+3pxdTOUisOyWXdY/nHokj1WPEL/d+abYlSf6iPxX9QlfiRiaPyQlxT J3pnIP42TnEKkEN5cwq3//rOu2eSVKp0EfCpAIfM2vQfDjN88p51DNmWD7gFDD4p w4YLgFJKsXyAdPD0xESxa7rwdhng8Abbop3/JRNhypg7waKkMTgQNm5Yp1TmejM8 zKjpvChmBpybq4pZHhviY8vkhbZny7GNPoOK8zUtOXrsvZu9e1wEsuub1+qGcVQU 2EES3WvliXXLwmgeDc8a+VIeJDcuBojwlK/MzefAIVs00lJYZV4EAuTT3VZbBlHf 3S2UVAIRu9mw0IRuzP6ZEUERP2z0EkSDKZL0PmZE+ZhoGz4hMkFE0S2L5HPX05eZ T141NnTrb3z9gbdFqm+6 =2H04 -----END PGP SIGNATURE----- --ZRLamLUCLuRJXeX8--