[rescue] Oracle making just a little harder to keep old machines in use

Phil Stracchino alaric at metrocast.net
Mon May 10 07:14:48 CDT 2010

On 05/10/10 08:00, Rich Kulawiec wrote:
> On Sat, May 08, 2010 at 11:05:50AM -0400, Patrick Finnegan wrote:
>> Why won't (GNU) tar work?  It does everything that you say you are 
>> wanting.
> Well, yes and no.
> Tar doesn't have code to cope with filesystems that are changing
> as they're being read.

What does, without taking a snapshot?

> It doesn't know how to split its output across multiple volumes.

I beg to differ:

       -M, --multi-volume
              create/list/extract multi-volume archive

       --volno-file FILE
              keep track of which volume of a multi-volume archive its
              in FILE; used with --multi-volume

> Tar's "catalog", if you will, is spread throughout the archive and
> not at the beginning.  Whether this is good or bad or indifferent
> depends, but I think for backups (as opposed to archives) it's not
> a good thing.

This is indeed a significant weakness of tar, and it's why when I was
using a backup system built from commin userspace tools, I used cpio
(well, actually, afio, which is file-compatible but better) rather than tar.

  Phil Stracchino, CDK#2     DoD#299792458     ICBM: 43.5607, -71.355
  alaric at caerllewys.net   alaric at metrocast.net   phil at co.ordinate.org
         Renaissance Man, Unix ronin, Perl hacker, Free Stater
                 It's not the years, it's the mileage.

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