From owner-freebsd-doc@freebsd.org Wed Jun 10 07:42:08 2020 Return-Path: Delivered-To: freebsd-doc@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 27BAC32C2F7 for ; Wed, 10 Jun 2020 07:42:08 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mailman.nyi.freebsd.org (mailman.nyi.freebsd.org [IPv6:2610:1c1:1:606c::50:13]) by mx1.freebsd.org (Postfix) with ESMTP id 49hf8J0Jrkz4qTm for ; Wed, 10 Jun 2020 07:42:08 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: by mailman.nyi.freebsd.org (Postfix) id 0AAAA32C4D8; Wed, 10 Jun 2020 07:42:08 +0000 (UTC) Delivered-To: doc@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 0A6ED32C3F4 for ; Wed, 10 Jun 2020 07:42:08 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 49hf8H6Y1tz4qTl for ; Wed, 10 Jun 2020 07:42:07 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2610:1c1:1:606c::50:1d]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id DC1BC231F0 for ; Wed, 10 Jun 2020 07:42:07 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org ([127.0.1.5]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id 05A7g7DO021225 for ; Wed, 10 Jun 2020 07:42:07 GMT (envelope-from bugzilla-noreply@freebsd.org) Received: (from www@localhost) by kenobi.freebsd.org (8.15.2/8.15.2/Submit) id 05A7g72m021214 for doc@FreeBSD.org; Wed, 10 Jun 2020 07:42:07 GMT (envelope-from bugzilla-noreply@freebsd.org) X-Authentication-Warning: kenobi.freebsd.org: www set sender to bugzilla-noreply@freebsd.org using -f From: bugzilla-noreply@freebsd.org To: doc@FreeBSD.org Subject: [Bug 247136] Handbook, section 2.3.1.1: dd(1) command uses "bs=1M" (slow), should be "bs=4k" (/much/ faster) Date: Wed, 10 Jun 2020 07:42:07 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Documentation X-Bugzilla-Component: Documentation X-Bugzilla-Version: Latest X-Bugzilla-Keywords: X-Bugzilla-Severity: Affects Many People X-Bugzilla-Who: andrew@tao11.riddles.org.uk X-Bugzilla-Status: New X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: doc@FreeBSD.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: cc Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugs.freebsd.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: freebsd-doc@freebsd.org X-Mailman-Version: 2.1.33 Precedence: list List-Id: Documentation project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 10 Jun 2020 07:42:08 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D247136 andrew@tao11.riddles.org.uk changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |andrew@tao11.riddles.org.uk --- Comment #1 from andrew@tao11.riddles.org.uk --- My experience and benchmarks differ - from a freebsd stable/11 system to a random USB2 thumb drive, I get a slowdown on the order of 8x from using 4k rather than 64k block size. Block sizes of 64k, 128k, 256k, 1m give me indistinguishable speeds (note, there is basically no reason to ever use a blocksize greater than MAXPHYS w= hen writing to a raw device, and that is 128k in standard builds). All block si= zes below 64k are slower for me. status=3Dprogress is not needed on freebsd since you can always just use control-T. --=20 You are receiving this mail because: You are the assignee for the bug.=