[ale] Problem restoring past large file in cpio

Chuck Huber chuck at cehuber.org
Wed Oct 18 17:18:20 EDT 2006


> Message: 7 Date: Wed, 18 Oct 2006 11:31:24 -0400 From: "Danny Cox" <DCox at icc.net>
> Subject: Re: [ale] Problem restoring past large file in cpio
> Wed, 2006-10-18 at 10:59 -0400, Chuck Huber wrote:
>>> The problem I'm encountering is that cpio won't restore past a
>>> large file (a DVD image of about 3.5G).  The listing it created
>>> during the backup has many files past it that are needed.
> 
> You might try pax.  It can read cpio archives, and get you
> through/past the large file.  You might try telling either one to
> restore everything EXCEPT that large file, and then work on just
> getting that file back.

Hmmm... I tried using pax and got the following error when trying to
list the archive:
    blackbird:/ # pax -f blackbird.20061007.full.cpio
    pax: Failed stat on blackbird.20061007.full.cpio: Value too large
for defined data type

    ATTENTION! pax archive volume change required.
    Ready for archive volume: 1
    Input archive name or "." to quit pax.
    Archive name >

This is interesting in that I was unaware of a file size limit on cpio.
 The size of the .cpio is just in excess of 10G.  When I try to get a
table of contents (cpio -it)  The last file listed is the file
immediately prior to the large one.  This would indicate that cpio can't
seek past the 2G point.

When I try to restore a specific file in front of the large one, all is
well.  When I try to restore a file from beyond the large one, it fails
with something on like "skipping 1xxxxx bytes of garbage.

With all that already written, I tried:

    cat xxx.cpio | pax

and was able to get a TOC down through and including the large .iso
file, but nothing past it.

All this would seem to indicate that the cpio format itself has a 2G
file size limit (32-bit signed integer for file sizes?).  In this case,
the large .iso starts before the 2G mark, but ends well beyond it.  I
haven't confirmed this - just a hypothesis.  That being the case would
render all my backups useless beyond 2G, leaving about 8G inaccessible.

Ideas on how to get past this would be greatly appreciated.  (Our
primary server is down until I get this fixed.)

Thanks,
    - Chuck

-- 
Chuck Huber
Duke Pro, Inc.
Office: 828-684-6022
Cell: 828-778-3776
Home: 828-683-7324



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