Debug / inspect guest state on Firecracker

[Alex Merritt]

Hello!

If one were to make changes to both Firecracker and OSv (e.g., in the para-virt interfaces) what options are there for debugging guest kernel state? I understand booting OSv alternatively on KVM/QEMU would make inspection possible, but doing so requires changes I wish to test to be implemented in QEMU.

Folks working on Firecracker tell me it does not have a gdbserver implementation like QEMU does, thus this path is not possible, currently.

How do you / would one go about debugging OSv behavior as a guest within Firecracker?

Thanks,

Alex Merritt

[Waldek Kozaczuk]

Hi,

I am afraid your only true debugging option on Firecracker is old-fashioned (:-) printf/log statements to the console. 

Alternatively, you can also use the monitoring and tracing mechanisms OSv provide - https://github.com/cloudius-systems/osv#debugging-monitoring-profiling-osv.

Maybe others have better ideas.

Thanks,

Alex Merritt