Tar: error! blocksize changed

[Jonathan Caplette_1]

Hi guys,

I'm trying to recover from a tar archive that I have on file system. I used "tar xvf /tmp/zip/bktmpapp.tar" to extract all files.... but at a time when extracting, tar stops and said "Tar: error! blocksize changed".

So I tried to change the blocksize to 1, with that command "tar xvfb /tmp/zip/bktmpapp.tar 1" but it still give me the error message.... I really need to have this archive... somebody know how???

Thanks
Jonathan

[Jonathan Caplette_1]

hum.. I forgot, the file size is more that 2 Go... could it be than, when I make my archive, and my fs wasn't supporting largesfiles it could have drop the rest of the archive.... I really think that's my problem!!!

Do somebody think the same as me?

[Ian Lochray]

Check out this HP article on the Knowledge Base. Document ID A1327736

[harry d brown jr]

Jonathan,

Did it extract any files, or did it die before then?

What OS are you running and do you have the latest patches?

live free or die
harry

[Patrick Wallek · Accepted solution]

Depending on which version of tar you are using (native HP-UX or GNUTar) the 2GB issue is more than likely your problem. If your filesystem did not support 2GB files when you created the tar file, then when it gets to that point, it will probably complain.

[Jonathan Caplette_1]

I don't know if where it" it give me the same answer at the same place....

Like I said could it have been cause my fs doesn't take largefiles, so the archive stopped at 2Go size, and I can't get the rest....???

[John Palmer]

Hi,

This could be one of several problems. From the knowledge base...

Tar reads the stored checksum from the tape and also uses other fields read from the tape to compute a checksum. When these checksums do not match, errors will display of this nature. The errors typically happen from backup media because the media somehow has been damaged or de-magnetized but other possibilities are listed below :

1. The tar tape might not be a tar tape at all and could be a cpio, fbackup, or some other backup utility tape.

2. The tar could have been written using the "O" option which is the pre-POSIX format and not the normal default of "N" which is the POSIX format.

3. The block factor was not the default and specified with the "b" option.

4. Verify what options were used to create the tar archive.

5. Check to make sure that tar is the current patched version for the operating system and also any kernel drivers that have been patched.

6. Do not rule out hardware. Attempt to archive off some files to a scratch tape and restore them. Make sure that the drive is performing as it normally should.


Regards,
John

[Judy Traynor]

have you tried to untar it with gnu tar -

you could also try to force the blocksize to 20


tar xvb20f /tmp/zip/bktm...

man tar to see the exact syntax - but it is the b switch.

also
did you look at the archive with tar tvf - to see how it was built?

that may provide some insight as well
There were a lot of good responses and mine should be regarded as simply "turning over those last few stones"

Good luck. Can you put the tarfile on a website we can get at?

[Jeff Schussele]

Hi Jonathan,

Yes, I believe the > 2Gb file size is a problem.
The HP-UX standard tar does not support file sizes greater than 2 Gb.

You should try GNU tar - it does support largefiles - can be had here:

http://hpux.cs.utah.edu/hppd/hpux/Gnu/tar-1.13.25/

Rgds,
Jeff

[Jeff Schussele]

Hi Jonathan,

Another thing to be aware of is if the tarball contains a file named the same as the actual tar file being extracted and you're extracting into the same directory where the original tar file is residing. The command will dutifully overwrite the tar file & then upon the next attempt to extract will squawk that the file has now changed.

Rgds,
Jeff