Question

Archive manager + nautilus is very usefull thing for any work with archives

If you install p7zip-full package Archive manager can work with 7z archives

But Archive manager use default settings for compressing

It is very bad

Classical example with javadoc:

Download it from http://www.oracle.com/technetwork/java/javase/downloads/index.html

unzip jdk-6u23-docs.zip
mv docs javadoc

7z a -t7z -m0=lzma -ms=on javadoc.7z javadoc
du -chb javadoc.7z
    24791075    javadoc.7z

But from man 7z and from LzmaLib.h we know that best compression is -mx=9 -mfb=273 -md=64m

Let’s try:

7z a -t7z -m0=lzma -mx=9 -mfb=273 -md=64m -ms=on javadoc.7z javadoc
du -chb javadoc.7z
    21308619    javadoc.7z

This is real better!

Question:
How to make Archive manager to use custom 7z command as default?

Answer 1

You’ll get a faster answer at superuser, for questions like this one.

Looking at the program, I discovered that it was File-Roller and the compression parameters were in an XML file. The manual mentioned nothing about configuration for the compression level. Finally, I found this information with Google(at bottom of page):

Veikk0 wrote on the 24 Jul 10 at 20:17
In my opinion this should get more
attention. Creating archives can be
frustrating and difficult at the
moment, mostly because to change the
compression level you have to:

1. Open gconf-editor (alt+F2 or from terminal).

2. Navigate to /apps/file-roller/general

3. Manually edit the key called compression_level to very_fast, fast,
   normal or maximum.

4. Create your archive with file-roller.

5. Repeat if you want to create another archive with different
   compression level.

Furthermore, there’s a bug for this: Bug 450019 – compression level