From owner-freebsd-questions@FreeBSD.ORG Fri Oct 31 13:15:52 2008 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 995461065687 for ; Fri, 31 Oct 2008 13:15:52 +0000 (UTC) (envelope-from freebsd-questions@m.gmane.org) Received: from ciao.gmane.org (main.gmane.org [80.91.229.2]) by mx1.freebsd.org (Postfix) with ESMTP id 4D6898FC21 for ; Fri, 31 Oct 2008 13:15:52 +0000 (UTC) (envelope-from freebsd-questions@m.gmane.org) Received: from list by ciao.gmane.org with local (Exim 4.43) id 1Kvtqt-0007MA-0S for freebsd-questions@freebsd.org; Fri, 31 Oct 2008 13:15:47 +0000 Received: from lara.cc.fer.hr ([161.53.72.113]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Fri, 31 Oct 2008 13:15:47 +0000 Received: from ivoras by lara.cc.fer.hr with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Fri, 31 Oct 2008 13:15:47 +0000 X-Injected-Via-Gmane: http://gmane.org/ To: freebsd-questions@freebsd.org From: Ivan Voras Date: Fri, 31 Oct 2008 14:16:38 +0100 Lines: 40 Message-ID: References: <490AC650.3000904@kukulies.org> <20081031110159.GA30244@icarus.home.lan> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig6A75BBE435C7D5E489DF7E41" X-Complaints-To: usenet@ger.gmane.org X-Gmane-NNTP-Posting-Host: lara.cc.fer.hr User-Agent: Thunderbird 2.0.0.17 (X11/20080925) In-Reply-To: <20081031110159.GA30244@icarus.home.lan> X-Enigmail-Version: 0.95.0 Sender: news Subject: Re: fastest raw device copy? X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 31 Oct 2008 13:15:52 -0000 This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig6A75BBE435C7D5E489DF7E41 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Jeremy Chadwick wrote: > On Fri, Oct 31, 2008 at 09:48:16AM +0100, Christoph Kukulies wrote: >> What would be the fastest way to do that sector by sector copy? I'm =20 >> using dd right now, >> >> dd if=3D/dev/ad0 of=3D/dev/da0 bs=3D10000000 > On the flip side, your blocksize (bs) there is quite high for no good > reason. I'd pick something more like bs=3D64k or bs=3D128k. The defau= lt > (512) is too small for what you want, but 10MBytes is silly. Not only that, but "10000000" isn't even correct - it needs to be a multiple of sector size. Generally, using suffixes will do the right thin= g: dd if=3D/dev/ad0 of=3D/dev/da0 bs=3D1m --------------enig6A75BBE435C7D5E489DF7E41 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFJCwU2ldnAQVacBcgRAt9RAKDQI13rdhkjPwJ2qgcFDy7oWFvIjQCgyhWc J2+LuU157FnLhikw2rmmZBE= =rb04 -----END PGP SIGNATURE----- --------------enig6A75BBE435C7D5E489DF7E41--