Single User Mode and init system recovery target discrepancies

Unix-like systems utilize Single User Mode to provide a minimal environment for filesystem repair and configuration diagnosis. This process typically involves passing specific flags to the bootloader to bypass the standard multi-user initialization sequence.

There is a lack of consistency in how different initialization systems handle the transition from the bootloader to the recovery shell. Specifically, the behavior of "emergency mode" versus "rescue mode" differs between legacy SysVinit and modern systemd implementations, particularly regarding which services are started and how the root filesystem is mounted.

• Does the distinction between emergency and rescue modes affect the availability of network-based recovery tools?
• How does the root password prompt behavior vary between these two modes across different init systems?