Which of the following commands brings a system running SysV init into a state in which it is safe to perform maintenance tasks? (Choose TWO correct answers.)
Which of the following commands brings a system running SysV init into a state in which it is safe to perform maintenance tasks? (Choose TWO correct answers.)
Commands that bring a system running SysV init into a state that is safe for maintenance are those that switch the system to single-user mode, which corresponds to runlevel 1. The 'init 1' command directly switches the system to runlevel 1, and the 'telinit 1' command does the same, acting as an alias for 'init 1'. These commands effectively reduce the system to its most basic state with only essential services running, allowing for maintenance tasks to be safely performed.
Options C. init 1 and D. telinit 1 bring a system running SysV init into a state in which it is safe to perform maintenance tasks. Option A: The shutdown -R 1 now command does not bring the system into a maintenance state. The -R option tells shutdown to reboot the system, not to enter a maintenance state. Option B: The shutdown -single now command does not bring the system into a maintenance state. The -single option tells shutdown to boot the system into single-user mode, which is a minimal environment used for maintenance tasks. However, the command must also specify a time at which the boot should occur.
Option C: The init 1 command tells init to switch to runlevel 1, which is the runlevel used to boot the system into single-user mode. Single-user mode is a minimal environment used for maintenance tasks and is safe to perform maintenance in. Option D: The telinit 1 command is equivalent to init 1 and tells init to switch to runlevel 1, which is the runlevel used to boot the system into single-user mode. Option E: The runlevel 1 command does not exist. The runlevel command is used to display the current runlevel of the system, not to change it.