/apache2/mods-available/disk_cache.conf

 1<IfModule mod_disk_cache.c>
 2# cache cleaning is done by htcacheclean, which can be configured in
 3# /etc/default/apache2
 4#
 5# For further information, see the comments in that file, 
 6# /usr/share/doc/apache2.2-common/README.Debian, and the htcacheclean(8)
 7# man page.
 8
 9	# This path must be the same as the one in /etc/default/apache2
10        CacheRoot /var/cache/apache2/mod_disk_cache
11
12	# This will also cache local documents. It usually makes more sense to
13	# put this into the configuration for just one virtual host.
14
15	#CacheEnable disk /
16
17        CacheDirLevels 5
18        CacheDirLength 3
19</IfModule>