SysV init has the ability to "respawn" a single PID, which I have used in the past (principally, replacing HP ServiceGuard clustering): xy:3:respawn:/usr/bin/r

SysV init has the ability to "respawn" a single PID, which I have used in the past (principally, replacing HP ServiceGuard clustering): xy:3:respawn:/usr/bin/return_to_life If the above process exits to much, the syslog will record "return to life respawning too quickly; disabled for 5 minutes." This is all much more pleasant in systemd, which can understand and restart a whole group of processes, even when the parent process exits in the course of startup.