Re: How long should a dd take

From	Robert Heller <heller@deepsoft.com>
Organization	Deepwoods Software
Subject	Re: How long should a dd take
References	<r5crp4$mn1$1@dont-email.me> <m7ydna-qVbLelOfDnZ2dnUU7-LXNnZ2d@giganews.com> <j58qkg-a6h.ln1@Telcontar.valinor>
Newsgroups	comp.os.linux.misc
Message-ID	<jsednc2T3LFt4OfDnZ2dnUU7-bXNnZ2d@giganews.com> (permalink)
Date	2020-03-24 16:38 -0500

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At Tue, 24 Mar 2020 21:46:11 +0100 "Carlos E.R." <robin_listas@es.invalid> wrote:

> 
> On 24/03/2020 14.21, Robert Heller wrote:
> > At Tue, 24 Mar 2020 11:43:31 +0000 The Natural Philosopher <tnp@invalid.invalid> wrote:
> > 
> >>
> >>
> >>
> >> I have a 1TB internal disk which is full and also showing a rather high
> >> error rate.
> >>
> >> I have ordered a new disk to replace it of 4TB capacity.
> >>
> >>
> >> It contains backup data so its non essential mostly
> >>
> >> Yesterday I started to dd it in its entirety to a USB connected 1TB drive.
> >>
> >> as in
> >>
> >> dd if=/dev/sdb of=/dev/sdc
> >>
> >>
> >> Since I wasn't concerned about optimising for speed. However 15 hours
> >> later dd is still running!
> >>
> >>
> >> Is this reasonable or is something actually wrong?
> > 
> > I believe the default value for bs is small, so it will take a long time.
> > 
> > dd is not the fastest way to copy a disk.
> > 
> > Specificying a larger value for bs will speed dd up.  Larger values for bs
> > will speed things up more.  How large a value depends on how much memory you
> > have avaiable.
> 
> Very large values don't speed copy noticeably, but small values such as 
> the default do impair speed greatly. Enough buffer size to read a whole 
> track is ideal.

Yes, the Law of dimishing returns...

> 
> 

-- 
Robert Heller             -- 978-544-6933 Cell: 413-658-7953 GV: 978-633-5364
Deepwoods Software        -- Custom Software Services
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How long should a dd take The Natural Philosopher <tnp@invalid.invalid> - 2020-03-24 11:43 +0000
  Re: How long should a dd take "Carlos E.R." <robin_listas@es.invalid> - 2020-03-24 13:13 +0100
    Re: How long should a dd take The Natural Philosopher <tnp@invalid.invalid> - 2020-03-24 16:37 +0000
      Re: How long should a dd take Robert Heller <heller@deepsoft.com> - 2020-03-24 12:25 -0500
        Re: How long should a dd take Eli the Bearded <*@eli.users.panix.com> - 2020-03-24 18:12 +0000
        Re: How long should a dd take The Natural Philosopher <tnp@invalid.invalid> - 2020-03-25 04:05 +0000
          Re: How long should a dd take "Carlos E.R." <robin_listas@es.invalid> - 2020-03-25 21:25 +0100
            Re: How long should a dd take The Natural Philosopher <tnp@invalid.invalid> - 2020-03-26 12:25 +0000
              Re: How long should a dd take "Carlos E.R." <robin_listas@es.invalid> - 2020-03-26 13:52 +0100
                Re: How long should a dd take The Natural Philosopher <tnp@invalid.invalid> - 2020-03-26 15:43 +0000
                Re: How long should a dd take Rich <rich@example.invalid> - 2020-03-26 15:55 +0000
                Re: How long should a dd take The Natural Philosopher <tnp@invalid.invalid> - 2020-03-26 18:36 +0000
                Re: How long should a dd take Rich <rich@example.invalid> - 2020-03-26 18:53 +0000
                Re: How long should a dd take The Natural Philosopher <tnp@invalid.invalid> - 2020-03-27 08:09 +0000
                Re: How long should a dd take Rich <rich@example.invalid> - 2020-03-27 10:00 +0000
                Re: How long should a dd take The Natural Philosopher <tnp@invalid.invalid> - 2020-03-27 10:15 +0000
                Re: How long should a dd take Rich <rich@example.invalid> - 2020-03-27 15:58 +0000
                Re: How long should a dd take Jean-David Beyer <jeandavid8@verizon.net> - 2020-03-27 13:43 -0400
                Re: How long should a dd take Roger Blake <rogblake@iname.invalid> - 2020-03-27 22:45 +0000
                Re: How long should a dd take ant@zimage.comANT (Ant) - 2020-03-28 17:00 -0500
                Re: How long should a dd take "Carlos E.R." <robin_listas@es.invalid> - 2020-03-27 14:11 +0100
                Re: How long should a dd take The Natural Philosopher <tnp@invalid.invalid> - 2020-03-27 13:49 +0000
                Re: How long should a dd take Rich <rich@example.invalid> - 2020-03-27 17:44 +0000
                Re: How long should a dd take The Natural Philosopher <tnp@invalid.invalid> - 2020-03-27 18:31 +0000
                Re: How long should a dd take Rich <rich@example.invalid> - 2020-03-27 19:58 +0000
                Re: How long should a dd take The Natural Philosopher <tnp@invalid.invalid> - 2020-03-27 20:14 +0000
                Re: How long should a dd take Robert Heller <heller@deepsoft.com> - 2020-03-27 15:13 -0500
                Re: How long should a dd take "Carlos E.R." <robin_listas@es.invalid> - 2020-03-27 21:47 +0100
                Re: How long should a dd take The Natural Philosopher <tnp@invalid.invalid> - 2020-03-28 05:30 +0000
                Re: How long should a dd take Robert Heller <heller@deepsoft.com> - 2020-03-28 07:33 -0500
                Re: How long should a dd take The Natural Philosopher <tnp@invalid.invalid> - 2020-03-28 13:41 +0000
                Re: How long should a dd take Robert Heller <heller@deepsoft.com> - 2020-03-28 09:47 -0500
                Re: How long should a dd take The Natural Philosopher <tnp@invalid.invalid> - 2020-03-28 17:48 +0000
                Re: How long should a dd take Robert Heller <heller@deepsoft.com> - 2020-03-28 14:27 -0500
                Re: How long should a dd take "Carlos E.R." <robin_listas@es.invalid> - 2020-03-28 22:22 +0100
                Re: How long should a dd take The Natural Philosopher <tnp@invalid.invalid> - 2020-03-29 06:41 +0100
                Re: How long should a dd take Jean-David Beyer <jeandavid8@verizon.net> - 2020-03-27 17:02 -0400
                Re: How long should a dd take Rich <rich@example.invalid> - 2020-03-27 21:12 +0000
                Re: How long should a dd take Robert Heller <heller@deepsoft.com> - 2020-03-27 20:35 -0500
                Re: How long should a dd take Jean-David Beyer <jeandavid8@verizon.net> - 2020-03-27 21:35 -0400
                Re: How long should a dd take Robert Heller <heller@deepsoft.com> - 2020-03-27 20:35 -0500
                Re: How long should a dd take "Carlos E.R." <robin_listas@es.invalid> - 2020-03-26 22:03 +0100
                Re: How long should a dd take "Anonymous Remailer (austria)" <mixmaster@remailer.privacy.at> - 2020-03-27 16:01 +0100
      Re: How long should a dd take Roger Blake <rogblake@iname.invalid> - 2020-03-24 19:59 +0000
  Re: How long should a dd take Marc Haber <mh+usenetspam1118@zugschl.us> - 2020-03-24 13:22 +0100
  Re: How long should a dd take Robert Heller <heller@deepsoft.com> - 2020-03-24 08:21 -0500
    Re: How long should a dd take Jean-David Beyer <jeandavid8@verizon.net> - 2020-03-24 14:22 -0400
    Re: How long should a dd take "Carlos E.R." <robin_listas@es.invalid> - 2020-03-24 21:46 +0100
      Re: How long should a dd take Jean-David Beyer <jeandavid8@verizon.net> - 2020-03-24 17:09 -0400
        Re: How long should a dd take "Carlos E.R." <robin_listas@es.invalid> - 2020-03-25 01:20 +0100
          Re: How long should a dd take Jean-David Beyer <jeandavid8@verizon.net> - 2020-03-24 22:06 -0400
      Re: How long should a dd take Robert Heller <heller@deepsoft.com> - 2020-03-24 16:38 -0500

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