"You're protecting something," Elias said to the metal chassis. "You’re stuck in a loop because you think you’re still the master."
He quickly typed show interfaces terse .
Elias sat back down. He didn't reach for the manual. He reached for his mental map of the Junos OS architecture. He remembered a corner case, an obscure behavior in the kernel regarding the preservation of the configuration database during a hard reset.
He located the process causing the hang. It was a chassisd daemon that had locked the file system. Standard troubleshooting would say to reboot the entire chassis. Elias didn't have the time for a fifteen-minute reboot cycle.