Re: No os.copy()? Why not?

From	Roy Smith <roy@panix.com>
Newsgroups	comp.lang.python
Subject	Re: No os.copy()? Why not?
Date	2012-04-04 08:14 -0400
Organization	PANIX Public Access Internet and UNIX, NYC
Message-ID	<roy-CFC7F3.08141804042012@news.panix.com> (permalink)
References	<38b3fc48-1d05-4373-b32e-64da95173864@pz2g2000pbc.googlegroups.com> <mailman.1290.1333482412.3037.python-list@python.org> <4f7be1e8$0$29999$c3e8da3$5496439d@news.astraweb.com> <87fwcj4zru.fsf@dpt-info.u-strasbg.fr>

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In article <87fwcj4zru.fsf@dpt-info.u-strasbg.fr>,
 Alain Ketterlin <alain@dpt-info.u-strasbg.fr> wrote:

> And sparse files are really hard to reproduce, at least on Unix: on
> Linux even the system's cp doesn't guarantee sparseness of the copy (the
> manual mentions a "crude heuristic").

I imagine the heuristic is to look for blocks of all zeros.  The problem 
is, unless you know the block size of the file system, you can only 
guess as to how many zeros in a row you need to look for.

In the old days, dump/restore used to know about sparse files.  But 
things like dump/restore really get inside the file system's kimono.  In 
today's world of SANs, WANs, and all sorts of virtual file-system-ish 
things, I would expect that's less common.

Thread

No os.copy()?  Why not? John Ladasky <john_ladasky@sbcglobal.net> - 2012-03-28 13:12 -0700
  Re: No os.copy()? Why not? alex23 <wuwei23@gmail.com> - 2012-03-28 21:50 -0700
    Re: No os.copy()? Why not? John Ladasky <john_ladasky@sbcglobal.net> - 2012-03-30 02:25 -0700
  Re: No os.copy()? Why not? Ian Kelly <ian.g.kelly@gmail.com> - 2012-04-02 14:48 -0600
  Re: No os.copy()?  Why not? HoneyMonster <someone@someplace.invalid> - 2012-04-02 21:11 +0000
    Re: No os.copy()?  Why not? Thomas Rachel <nutznetz-0c1b6768-bfa9-48d5-a470-7603bd3aa915@spamschutz.glglgl.de> - 2012-04-03 08:24 +0200
      Re: No os.copy()? Why not? John Ladasky <john_ladasky@sbcglobal.net> - 2012-04-03 02:34 -0700
        Re: No os.copy()? Why not? Thomas Rachel <nutznetz-0c1b6768-bfa9-48d5-a470-7603bd3aa915@spamschutz.glglgl.de> - 2012-04-04 14:30 +0200
      Re: No os.copy()? Why not? Ian Kelly <ian.g.kelly@gmail.com> - 2012-04-03 10:29 -0600
  Re: No os.copy()?  Why not? D'Arcy Cain <darcy@druid.net> - 2012-04-03 15:46 -0400
    Re: No os.copy()?  Why not? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-04-04 05:53 +0000
      Re: No os.copy()? Why not? Chris Angelico <rosuav@gmail.com> - 2012-04-04 18:37 +1000
        Re: No os.copy()? Why not? Steve Howell <showell30@yahoo.com> - 2012-04-04 08:15 -0700
      Re: No os.copy()?  Why not? Alain Ketterlin <alain@dpt-info.u-strasbg.fr> - 2012-04-04 11:22 +0200
        Re: No os.copy()?  Why not? Roy Smith <roy@panix.com> - 2012-04-04 08:14 -0400
          Re: No os.copy()?  Why not? Nobody <nobody@nowhere.com> - 2012-04-04 20:37 +0100
      Re: No os.copy()?  Why not? Roy Smith <roy@panix.com> - 2012-04-04 08:08 -0400
        Re: No os.copy()? Why not? Chris Angelico <rosuav@gmail.com> - 2012-04-04 22:17 +1000
  Re: No os.copy()?  Why not? Tycho Andersen <tycho@tycho.ws> - 2012-04-03 15:10 -0500
  Re: Re: No os.copy()?  Why not? Evan Driscoll <driscoll@cs.wisc.edu> - 2012-04-03 15:21 -0500

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