1. Introduction In this how-to we will present you how to size your servers according to the number of users in your organization that will use OpenOTP. 2. Recommendations for 500 Users 1 dedicated server or Virtual machine with Linux (2 for High Availability). Server configuration: 3GHz processor (4 cores). 8GB RAM memory. 200MB disk space for installation files. 10GB disk space for log files and DB. Optionally 1 YubiHSM for hardware crypto.