is the same as device busy
shows the availability of the path of devices
can be prevented with more devices
can be prevented by reducing the paging rate
synchronize access to local resources
synchronize access to global resources
are used to avoid local locks.
prevent access to global resources
are used only for capacity planning
are most useful for showing performance problems
are useless for capacity planning
cannot show the system paging rate
authentication problem
physical problem
human problem
none of these
grappling hook program
main program
secondary program
primary storage