Which user space utility is used to manage other applications in the user space?

secd is the security daemon responsible for handling authentication and authorization requests such as name mapping and LDAP/AD lookups, not for managing other processes.

RDB (Replicated Database) is the infrastructure used to replicate cluster configuration data across nodes, not a utility for managing user space applications.

Notifyd is a notification daemon that handles event notifications within ONTAP, not a process manager for other user space applications.

spmd, the Storage Process Manager Daemon, acts as the supervisor for other user space processes in ONTAP. It is responsible for launching, monitoring, and restarting other daemons and applications running outside the kernel, making it the process management utility for the user space environment.