[vox-tech] gzip bug?

Thu, 14 Mar 2002 13:49:56 -0800 (PST)

Before you file a bug report, may I suggest:

   - Try gunzip-ing on a different Linux system.

It might tell you something.

-Mark

On Thu, 14 Mar 2002, Peter Jay Salzman wrote:

> hmmm... i'm still reluctant to say that there's a bug in gzip or bzip2.
> it would be like saying that mcdonalds has been making french fries
> incorrectly all these years.  it's like, someone should've noticed by
> now.
>
> but i'm fresh out of ideas.  i'm not sure what else to say.
>
> i took a look at deja just now and didn't find anything particularly
> useful for your situation.  why don't you file that bug report and see
> what they have to say?
>
> pete
>
> begin Kevin Dawson <kdawson@ucdavis.edu>
> > Hi Pete,
> >
> > The files I'm having the problem with are just 50M and 30M after gzip.
> >
> > I followed your suggestion. Everything was going fine up to 1M. Using
> > 10M, I had to learn that I didn't have 20G disk space available on
> > /home. Using 100k, the created file size is in the range of my problem
> > files (50M), can be compressed to only 50k, and uncompressed perfectly.
> > It looks like that the problem is dependent on the size of the
> > compressed file (30M in my case).
> >
> > bunzip2 is also having trouble. It says:
> > bunzip2: Data integrity error when decompressing.
> > 	Input file=bigfile.bz2, output file=bigfile
> >
> > It is possible that the compressed file(s) have become corrupted.
> > You can use the -tvv option to test integrity of such files.
> >
> > When I do the test, it will print
> > [N: huff+mtf rt+rld] whereas N goes up to 29.
> > Then it prints: data integrity (CRC) error in data.
> >
> > When gunzipping the files, I don't hear any unusual disk churning.
> >
> > Thanks again,
> >
> > Kevin
> >
> >
> >
> >
> >
> >
> > -----Original Message-----
> > From: vox-tech-admin@lists.lugod.org
> > [mailto:vox-tech-admin@lists.lugod.org] On Behalf Of Peter Jay Salzman
> > Sent: Thursday, March 14, 2002 10:38 AM
> > To: vox-tech@lists.lugod.org
> > Subject: Re: [vox-tech] gzip bug?
> >
> > hi kevin,
> >
> > just out of curiosity, when you say it happens with all big files, how
> > big is big?  1k?  10k?  100k?  are youa bioinformatics dude?  ;-)  what
> > i'm getting at is -- are you dealing with files near the 2GB limit?
> >
> > what happens when you try to do something like:
> >
> > dd if=/dev/zero of=mybigfile count=10k
> > cp mybigfile myotherbigfile
> > gzip mybigfile
> > gzip -d mybigfile
> > diff mybigfile.gz myotherbigfile
> >
> > change the 10k to whatever you need to reproduce the crc error.  also,
> > 10k of /dev/zero should produce about a mp3 sized file (5 Megs).
> >
> > if you can reproduce the CRC error this way, i totally encourage you to
> > write to bug-gzip@gnu.org.   gzip is one of the things that really ought
> > to be rock solid.  you can screw around with USB and TV tuner cards, but
> > gzip and bzip2 are our meat and potatoes.
> >
> > btw, does this problem happen with bzip2?
> >
> > also, when you gunzip these large files, how hard does your machine
> > thrash?  does the hard drive go like mad?
> >
> > pete
> >
> > begin Kevin Dawson <kdawson@ucdavis.edu>
> > > Hi Pete,
> > >
> > > Thank you for your suggestion. I'm using gzip 1.3 and gunzip 1.3 on a
> > > VFS file system. I'm having problems with practically all big files.
> > The
> > > files are corrupted without ever leaving the Linux machine. For
> > > trouble-shooting with WinZip, I transferred some files to Windows
> > using
> > > Samba.
> > >
> > > The exact error message reads as:
> > > gunzip: MX.mat.gz: invalid compressed data--crc error
> > >
> > > Your filter suggestion is great. It works, although, I'm still getting
> > > the error message:
> > > gzip: stdin: invalid compress data--crc error
> > >
> > > Thank you,
> > > Kevin
> > >
> > >
> > > -----Original Message-----
> > > From: vox-tech-admin@lists.lugod.org
> > > [mailto:vox-tech-admin@lists.lugod.org] On Behalf Of Peter Jay Salzman
> > > Sent: Thursday, March 14, 2002 9:59 AM
> > > To: vox-tech@lists.lugod.org
> > > Subject: Re: [vox-tech] gzip bug?
> > >
> > > hi kevin,
> > >
> > > stream of consciousness:
> > >
> > > are you saying ALL files on redhat can't be gunzipped?  or only
> > > particular files?  was this file transfered using windows ftp or http?
> > > perhaps it went through a NL/CR conversion?  faulty kermit transfer?
> > > where was the file created?  under a vfat system or under a VFS
> > (linux)
> > > system?
> > >
> > > try to use gzip as a filter:
> > >
> > > gzip -d <myfile.gz >myfile
> > >
> > > this will unzip as far as gzip can go before reaching the CRC error.
> > > it might recover some of your data.
> > >
> > > also, can you post the exact error message (always a good thing to do
> > > when asking for help when something complains!)
> > >
> > > can you post gzip's version number and mail me (not the list) a copy
> > of
> > > the file you're trying to unzip?  i'll give it go here.
> > >
> > > pete
> > >
> > >
> > > begin Kevin Dawson <kdawson@ucdavis.edu>
> > > > Hi,
> > > >
> > > > I cannot gunzip my gzipped files on RedHat 7.1. I get CRC error
> > > > messages. On the other hand, when the files are transferred to
> > > Windows,
> > > > WinZip opens them without any complain. Do you know any known bugs
> > in
> > > > gzip or gunzip? Do you know another uncompressing utility on Linux
> > > which
> > > > does not invoke RedHat's gunzip to uncompress a .gz file.
> > > >
> > > > Any suggestion is appreciated.
> > > >
> > > > Kevin
> > > >
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--
Mark K. Kim
http://www.cbreak.org/
PGP key available upon request.