Question: how to install qcow2 image in gns3?
Answer: Choose "Default" for the VM type and hit next. ... 
Select New Image, browse to your downloaded qcow2 file, and click open to upload the file to your GNS3 VM. ... 
Select the ASA symbol, change the category to Security Devices, and set the console type to vnc. ... 
Click the network tab. ... 
Click the Advanced settings tab.