R

reboot command, System Shutdown Commands

rebooting a system, forcing a crash dump, Forcing a Crash Dump and Reboot of the System

remove entries from GRUB menu (how to), x86: How to Remove a Boot Entry From the GRUB Menu

remove-entry subcommand, bootadm, x86: Administering the GRUB Configuration by Using the bootadm Command

run level

0 (power-down level), How Run Levels Work

1 (single-user level), How Run Levels Work

2 (multiuser level), How Run Levels Work

3 (multiuser with NFS), How Run Levels Work

what happens when system is brought to, What Happens When a System Is Booted to a Multiuser State (Run Level 3)

default run level, How Run Levels Work

definition, How Run Levels Work

determining (how to), Determining a System's Current Run Level

s or S (single-user level), How Run Levels Work

run level booting, booting a system to a multiuser state, How to Boot a System to a Multiuser State (Run Level 3)

run levels or milestones, when to use, When to Use Run Levels or Milestones