Hey all,
I have a directory that is 497M large.
I ran the following:

Yet, the resulting .tar file compressed down to 483M.

I expected a much large compression. Any ideas?
Thanks.

tar does not compress files. It only does archive the files. To do compression, try bzip2 or gzip.
Hope this helps...

If the directory contains binaries (as opposed to text files), gzip compression (what the 'z' option uses) will not do much. You can try the 'j' option instead to use bzip2 compression. It will take 2-3 times as long though.

In the end, there may not be much of a change. All data is not compressible. Some data is already compressed. You may be at or near the limit that you can reduce the size of the data (at least in a reasonable time frame).

You appear to be confused or misinformed. Try 'man tar'. Tar will automatically invoke either gzip or bzip2 via the 'z' and 'j' options.

Oopz...
My bad...
Too used to my style(of tar'ing, then only bzip2 it)...

With the cvjf this only compressed the directory 1M more, from 484 to 483M.

And these are text files (html), and images, and movies.

Any way that I can really compress from 497M to a much smaller amount, for back up purposes.

Thanks

The movies are already compressed (most encoders perform a relatively high level of compression). The HTML files will compress by a large amount, but they likely only constitute a very small percentage of the data. There are other compression algorithms, and they take progressively longer and consume more resource for progressively less gain.

With a few additional manual steps, you can use 7-zip. You can give that a try, however, keep in mind that as you venture further from mainstream, you may have more difficulty restoring your data when you need it.

hmmm, ok

So I guess im stuck with what I got. Thanks

Try KGB Archiver for linux:
http://kgbarchiver.net/?page=download

It will take a lot of time ( more than expectation ) to compress/decompress files.
Setup of Microsoft Office 2003[approx 550 mb] was compressed to 5 mb using kgb.
I am not having any idea, how much it is useful for compressing movies.

Uh, KGB is a fake, last I heard.

This is the computer science equivalent to a perpetual motion machine. If it can actually achieve that level of compression on an arbitrary (already compressed) source, then why not take the output and compress it again, and again, until the file is only one byte?

I think their test case was found to be a fraud, which actually downloaded the files. On arbitrary testing, it was found to be not as good as other compressors.