GNS3 provides a streamlined method via an appliance template:
Once you have the asav9-12-2-9.qcow2 file, follow this guide for a standard KVM environment (Ubuntu/Debian). Asav9-12-2-9.qcow2 Download
Search for "Adaptive Security Virtual Appliance (ASAv)" and navigate to the release section. 2. Lab Community Resources GNS3 provides a streamlined method via an appliance
To the uninitiated, the filename looked like a jumble of alphanumeric soup. But to Elena, it was a precise instruction manual. Asav9-12-2-9.qcow2 Download
To get production-like throughput:
How to Download and Use Asav9-12-2-9.qcow2 (Cisco ASAv Image)