You need to enable AWStats as it is not enabled by default on VPS installations. The following tutorial shows an extremely easy way to enable AWStats on your server and all cPanel accounts.
Step 1: Log into WHM in your VPS Account Information email.
Step 2: Enter “Statistic” into the “Find” box in the upper left-hand corner of WHM and Click on “Statistics Software Configuration“.
Step 3: Check the box for “Awstats” and click the “Save” button
Step 4: Check the box for “Active by Default” on the “Awstats” row. Click on “Save” again.
AWStats is now enabled on all accounts on the VPS. Do allow up to 48 hours for AWStats to begin providing data.