Web server log files contain mostly useful information and if your website is busy you might find that your logs are full of entries you don't really need.

Here is a simple technique to reduce your server log file sizes and make them easier to read.

Simply stop logging requests for information you don't really need.

Open up your apache2.conf file:

pico /etc/apache2/apache2.conf

Look for the section containing your log file entries:

LogFormat "%h %l %u %t etc...

Right after add these lines

SetEnvIf Request_URI \.gif no-log
SetEnvIf Request_URI \.jpg no-log
SetEnvIf Request_URI \.jpeg no-log
SetEnvIf Request_URI \.css no-log
SetEnvIf Request_URI \.js no-log

You can add as many of these env entries you please. If you want to prevent logging of a particular folder relative to the / root folder, eg for your CMS or similar simply add a line like this:

SetEnvIf Request_URI ^/subfolder/ no-log

Or if you want to protect all folder contents with the same name no matter where in the root path they are then use this:

SetEnvIf Request_URI "\/subfolder\/*" no-log

Now look for the <VirtualHost *> section for the website you want to stop the logging on these items and add the env=!no-log to the end of the existing CustomLog entry as follows:

CustomLog /var/www/sitename.com/logs/access_log common env=!no-log

Now save and exit and restart Apache as follows:

/etc/init.d/apache2 reload

You can test this by browsing a few pages on your site and then viewing your access log file, you should see the recent entries are a lot cleaner.