Troubleshooting tools

Do you guys know what are (if there’s any) tools available in this crappy OS where I can determine what process is reading/writing on my disks?
Every night my fans go full speed and top won’t give me any hint of what’s happening. Tools like iotop or lsof aren’t available.
I would love to know who’s the ■■■■■ that made the decision to remove everything useful from the OS. Even tcpdump is gone.