Re: Rescueing a DLT tarball on a Mac

From: Thor Lancelot Simon (tls_at_panix.com)
Date: 11/02/05 

Date: Wed, 2 Nov 2005 18:17:03 +0000 (UTC)

In article <1130885663.167298.157190@z14g2000cwz.googlegroups.com>,
Maury Markowitz <maury_markowitz@hotmail.com> wrote:
>Excellent info, thanks. Just for clarification, Rhapsody is not a
>program, but Apple's code name for what became OS X.
>
>If I understand your comments correctly, the real problem here is the
>block size issue. Reading your post now did trigger a memory, and I do
>believe I used tar csf.

You "used tar csf" to do *what*? To create the archive file on disk? Or
to write the archive directly to tape?

I'd be astonished if you used the "-s" switch to tar. Do you mean "cSf",
or perhaps "czf", or something else?

If you used tar to write the archive to tape you have 10k blocks on the
tape and it will probably work fine -- you can read it right back off
with tar x (in this case, probably tar xvf /dev/nrst0 though you may
want to do a tar tvf /dev/nrst0 first to see what you'are about to extract).

If you created the file on disk with tar and then wrote it to tape with
dd and dd's default blocksize of 512, all bets are off. While you might
be able to read it back on the _same_ system you wrote it on, there's no
real convention for _how_ to reblock such small writes, so the odds of
being able to read it back on any _other_ system are quite poor. 

-- 
 Thor Lancelot Simon	                                      tls@rek.tjls.com
"The inconsistency is startling, though admittedly, if consistency is to be
 abandoned or transcended, there is no problem."		- Noam Chomsky

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