Linux usleep: command not found, Why?
as Tcampbell already wrote it should be in initscripts
you can type
ls -al /bin/usleep
rpm -qV initscripts
to see if something happened with your usleep
if its not there i would suspect that there is a serious disk error or the machine has been broken into
What distribution? On my RHEL 5 system, usleep is part of the initscripts RPM.