link deflate.load from mods-available to mods-enabled.

and in your vhost config add this:

        <IfModule mod_deflate.c>
                CustomLog /var/log/apache2/virtualhostname-deflate.log deflate
                SetOutputFilter DEFLATE
        </IfModule>


use a specific conf
/etc/apache2/conf.d/deflate.conf:

<IfModule mod_deflate.c>
 DeflateCompressionLevel 3

 DeflateFilterNote Input instream
 DeflateFilterNote Output outstream
 DeflateFilterNote Ratio ratio

 LogFormat '"%r" %{outstream}n/%{instream}n (%{ratio}n%%)' deflate

 # Netscape 4.x has some problems...
 BrowserMatch ^Mozilla/4 gzip-only-text/html

 # Netscape 4.06-4.08 have some more problems
 BrowserMatch ^Mozilla/4\.0[678] no-gzip

 # MSIE masquerades as Netscape, but it is fine
 #BrowserMatch \bMSIE !no-gzip !gzip-only-text/html

 # NOTE: Due to a bug in mod_setenvif up to Apache 2.0.48
 # the above regex won't work. You can use the following
 # workaround to get the desired effect:
 BrowserMatch \bMSI[E] !no-gzip !gzip-only-text/html

 # Don't compress images, java scripts and style sheets
 SetEnvIfNoCase Request_URI \
   \.(?:gif|jpe?g|png|js|css)$ no-gzip dont-vary

 # Make sure proxies don't deliver the wrong content
 # this needs mod_headers but it's very important
 # so I don't add a IfModule around it
 Header append Vary User-Agent env=!dont-vary

</IfModule>