gunzip test errors

[Milan Muralidharan]

Testing the zipped file with 'gunzip -t'
shows "Unknown error". These are the zipped backup files. What i have to check for??
Appreciate your details.

[John Palmer]

How have you created your 'zipped backup files'?

[Milan Muralidharan]

With 'tar cvf - file1 file2 ...|gzip > zippedfile & ' command.

[John Palmer]

Ther shouldn't be any problem with that.

Have you tested the contents with
gzcat | tar tvf -

If that's ok then it's 'gunzip -t' that's the problem.

[Milan Muralidharan]

John,
It brings the follwing output:
"tar: usage tar [-]{txruc}[eONvVwAfblhm{op}][0-7[lmh]] [tapefile] [blocksize] fi
le1 file2... "

I think the arguments are not in line. Let me know your thoughts.

Thanks

[John Palmer]

The arguments to tar are:-
tvf -
that is tvf-
did you omit the space?

[Milan Muralidharan]

John,
It works and lists the file. You are amazing. Thanks a lot.

[Milan Muralidharan]

John,
With another large zipped backup archive file when i use the "gzcat | tar tvf - " i get the folg error message:
: Unknown error
Tar: blocksize = 0; broken pipe?

I am not using any named pipe in this case.
Why am i getting this error. Appreciate your details.

[John Palmer]

Milan,

In this case, gzcat is reporting the same error 'Unknown error' as gunzip -t was yesterday.

tar is just complaining that no data is being piped to it.

How big is the gzipped file ?

[Milan Muralidharan]

The tar zipped file size is 12.5 Gb. The unzipped filesize could be about 100Gb.
This is the cold backup file for the production database.

[John Palmer]

Milan,

I thought that you were going to say that...
tar does not support large files (> 2Gb) and I suspect that gzip/gunzip/gzcat don't either.

[Milan Muralidharan]

I thought the tar -xvf along with gunzip could run as a background progress to extract the files to its original location irrespective of the size of the tar zipped file.