From owner-freebsd-ports@FreeBSD.ORG Fri Jan 17 21:17:52 2014 Return-Path: Delivered-To: ports@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 31A027EF for ; Fri, 17 Jan 2014 21:17:52 +0000 (UTC) Received: from mail-pd0-x234.google.com (mail-pd0-x234.google.com [IPv6:2607:f8b0:400e:c02::234]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id 052AC1B3C for ; Fri, 17 Jan 2014 21:17:51 +0000 (UTC) Received: by mail-pd0-f180.google.com with SMTP id x10so3201017pdj.11 for ; Fri, 17 Jan 2014 13:17:51 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:date:message-id:subject :from:to:cc:content-type; bh=kqWPu3CCTwnOHuvOFMzeQ4FoiJz6Jfj1uiMWcs6zNGE=; b=KsaCxDe7bJ5QnRtAmX7lPyeaslfGTTXQadvWIoNAsrJU8TxpfO+cvwHo21ozFomd0O CJOV4QThAPg9Kqs6XlCT7OoSQA1PCcryuiKm1LXLPXhm/AEDsRy5LrwQ8XvsykKNLLzT whBSShMLrbvadkV05l2w33G4YcFcyXWeIrDjrJW6gTQRU//m7mPY35eeyiWhHHtTZtF4 djWNyRhT24rbZ2nfjziWMQcpJpcZMmpxADSFXneB534GZuYoD1jHwvzx8EiX9sqNxgjf 7nXuqfqK53a57rEnhemhu/1KffLVdRi/Y+dnR+nK5GfctwxRB9hyyirfaYgVEAztZ6/P XSFA== MIME-Version: 1.0 X-Received: by 10.69.31.97 with SMTP id kl1mr4680089pbd.62.1389993471502; Fri, 17 Jan 2014 13:17:51 -0800 (PST) Sender: kob6558@gmail.com Received: by 10.67.30.1 with HTTP; Fri, 17 Jan 2014 13:17:51 -0800 (PST) In-Reply-To: References: Date: Fri, 17 Jan 2014 13:17:51 -0800 X-Google-Sender-Auth: zTiDmOLbetcGq-UBZNpjfm1kwzo Message-ID: Subject: Re: clonehdd followup From: Kevin Oberman To: paul beard Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-Content-Filtered-By: Mailman/MimeDel 2.1.17 Cc: FreeBSD Ports , bart@tapolsky.net.ua X-BeenThere: freebsd-ports@freebsd.org X-Mailman-Version: 2.1.17 Precedence: list List-Id: Porting software to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 17 Jan 2014 21:17:52 -0000 On Fri, Jan 17, 2014 at 8:51 AM, paul beard wrote: > Grr. The return key should not be the same as Send. > > I had some problems with clonehdd that turned out to be hardware issued: = my > disks has somehow defaulted to PIO4 from UDMA which made this process run > so slow it would just quit with finishing. > > Now things are more what I expect, completing a clone of my root disk in > 524 minutes, down from multiple days=E2=80=A6 > > But it still seems slow if the disks are 1.5Gb/sec SATA disks. Looking > around, it looks like this might be useful to speed things up. > > > http://www.wonkity.com/~wblock/docs/html/disksetup.html > > -- > Paul Beard / www.paulbeard.org/ > Remember that 1.5GB/s is the speed supported by the electronics and the cache. It is not the speed that the disk actually reads or writes from/to the platters. When cloning, very little of the data is in cache, so you are generally limited by seek times (should be minimal if the code is well done) and rotational speed. The really then boils down to transfer speeds are going ot be close to what is possible with the rotational speed. Since I lack specifics on your disk drive, you'll have to do the arithmetic. It will only be approximate because of the tricks disks use for spatial optimization, but it won't be 1.5GB/s. Also be aware that disabling write cache will significantly reduce performance. (It should be "on" by default.) N.B. Several statements above are incomplete or slightly inaccurate. I think they are close enough for this discussion and being both complete and accurate would make this message way too long. --=20 R. Kevin Oberman, Network Engineer, Retired E-mail: rkoberman@gmail.com