In terms of drawbacks, the main ones are lack of support, possible instability, and potential security issues. Also, updating such an image might be complicated if you can't apply official patches or if the patch has conflicts with updates.
Compatibility with other Fortinet products like FortiManager, FortiAnalyzer, or FortiCloud. The patched image should integrate the same as the official build if FortiOS compatibility is maintained. fgtvm64kvmv721fbuild1254fortinetoutkvmqcow2 patched
Documentation is another point. Does this image come with any documentation? If it's a patched version from a third party, there might not be official guides, which could make setup more challenging. Also, support—if something breaks, Fortinet isn't likely to support a modified image. In terms of drawbacks, the main ones are
I should mention what FortiOS does. FortiOS is the operating system for FortiGate appliances, which are firewalls. So this image is the virtual appliance version for KVM. The user might be deploying a FortiGate virtual firewall in a cloud environment or on-prem. The patched image should integrate the same as
Security is a big concern. Third-party patches might introduce vulnerabilities or remove certain security restrictions. The user should be aware that using non-official images can expose them to risks. They should verify the integrity of the image and the source's trustworthiness.