From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from pigeon.gentoo.org ([208.92.234.80] helo=lists.gentoo.org) by finch.gentoo.org with esmtp (Exim 4.60) (envelope-from ) id 1NM11T-00055W-6T for garchives@archives.gentoo.org; Sat, 19 Dec 2009 15:15:11 +0000 Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id A1CFAE0848; Sat, 19 Dec 2009 15:15:01 +0000 (UTC) Received: from mail.digimed.co.uk (82-69-83-178.dsl.in-addr.zen.co.uk [82.69.83.178]) by pigeon.gentoo.org (Postfix) with ESMTP id 3C66CE0848 for ; Sat, 19 Dec 2009 15:15:01 +0000 (UTC) Received: from digimed.co.uk (grunthos.digimed.co.uk [192.168.1.4]) (using TLSv1 with cipher DHE-RSA-AES128-SHA (128/128 bits)) (No client certificate requested) by mail.digimed.co.uk (Postfix) with ESMTPSA id 735C54886E5 for ; Sat, 19 Dec 2009 15:15:00 +0000 (GMT) Date: Sat, 19 Dec 2009 15:15:45 +0000 From: Neil Bothwick To: gentoo-user@lists.gentoo.org Subject: Re: [gentoo-user] Re: dd - bytes at a time Message-ID: <20091219151545.500abcf4@digimed.co.uk> In-Reply-To: <758FF530-4CDB-49A8-95DD-5D01B1291C4C@stellar.eclipse.co.uk> References: <49bf44f10912161049v3768a3f8m60dddbae4b8777b@mail.gmail.com> <15719e8b0912161154o6f634c9bk6b1f9e3f9204ac20@mail.gmail.com> <49bf44f10912180908x6fa39920k7048c718a16a018b@mail.gmail.com> <49bf44f10912181505h7993994h4bf342380654dbf6@mail.gmail.com> <4B2C3187.7060701@cox.net> <49bf44f10912181758q15cb100k87bb42634d799cee@mail.gmail.com> <20091219105915.1c9bc778@digimed.co.uk> <758FF530-4CDB-49A8-95DD-5D01B1291C4C@stellar.eclipse.co.uk> Organization: Digital Media Production X-Mailer: Claws Mail 3.7.3cvs39 (GTK+ 2.18.5; i686-pc-linux-gnu) X-GPG-Fingerprint: 7260 0F33 97EC 2F1E 7667 FE37 BA6E 1A97 4375 1903 Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-user@lists.gentoo.org Reply-to: gentoo-user@lists.gentoo.org Mime-Version: 1.0 Content-Type: multipart/signed; micalg=PGP-SHA1; boundary="Sig_/bjJ3orWK_vOefeyYBDP6Kgn"; protocol="application/pgp-signature" X-Archives-Salt: 4e81ba3d-a17f-4187-a1c8-ce7521bdb4b4 X-Archives-Hash: 3d940eef35a60c0338d7bdfccc43a1a0 --Sig_/bjJ3orWK_vOefeyYBDP6Kgn Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable On Sat, 19 Dec 2009 12:11:27 +0000, Stroller wrote: > > Incidentally, if you want to use dd, adding bs=3D4096 speeds it up quite > > significantly. =20 >=20 > Thank you. I have always wondered what the optimal bs might be. > And why - could you possibly explain that, please? >=20 > Is bs=3D4096 best for all disk-based operations? Many filesystems are set up with 4K blocks, so matching this with dd is more efficient. The default is 512 byte blocks and anything larger than this is good, I sometimes use 40960 but that isn't significantly faster. I prefer to avoid using dd on hard disks altogether, it's just so damn slow for large amounts of data. --=20 Neil Bothwick You can't teach a new mouse old clicks. --Sig_/bjJ3orWK_vOefeyYBDP6Kgn Content-Type: application/pgp-signature; name=signature.asc Content-Disposition: attachment; filename=signature.asc -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.13 (GNU/Linux) iEYEARECAAYFAkss7ikACgkQum4al0N1GQNpqQCfbuXzi5+L9R0OlOclltT5p0wW 2nEAn2XKT58NaCKoEZFCuzbkB7A2rkyi =O6JZ -----END PGP SIGNATURE----- --Sig_/bjJ3orWK_vOefeyYBDP6Kgn--