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Date: Thu, 26 Mar 2009 17:01:06 +0000
From: David Malone <dwmalone@maths.tcd.ie>
To: "Mikhail T." <mi+thun@aldan.algebra.com>
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Cc: Danny Braniss <danny@cs.huji.ac.il>, freebsd-stable@freebsd.org,
	fs@freebsd.org
Subject: Re: dump | restore fails: unknown tape header type 1853384566
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On Tue, Mar 24, 2009 at 02:03:12PM -0400, Mikhail T. wrote:
> Same problem:
> 
>    restore -rf ibmo.0.2009-03-24.dump
>    load: 0.55  cmd: restore 11303 [nbufkv] 3.53u 3.91s 4% 27980k
>    unknown tape header type 213474529
>    abort? [yn]
> 
> Please, advise. Thanks! Yours,

Hi Mikhail,

If you actually need to get a dump back that restore can't read,
you can try the "-D" option that I added a few years ago. Dump and
restore expect things to be in a block format, but if (say) dump
outputs a few bytes into the stream due to a bug, then the entire
end of the dump can become unreadable. The -D option to restore
tells it to try hard to get back in sync again.

I'd guess you've tripped over either a bug in dump or restore. If
you can file a PR, particularly with access to a sample dump, then
I can have a look and see if I can figure out what's going on.

	Daid.