When working in Linux single-user mode (runlevel 1), you typically only get one active TTY session (usually on tty1). This becomes particularly challenging during extended recovery operations like RAID reconstruction, where you might need:

• Primary terminal for long-running recovery commands
• Secondary terminal for configuration edits
• Tertiary terminal for log monitoring

Here's the most straightforward method to spawn a new shell on another virtual terminal:

# On tty1 (your current single-user session)
sudo /sbin/agetty -n -l /bin/bash 38400 tty2 &

Key parameters explained:

• -n: Disables prompt for username
• -l /bin/bash: Specifies the shell to launch
• 38400: Baud rate (legacy parameter, still required)
• tty2: Target terminal (use tty3-tty6 for more sessions)

For systems using systemd (most modern distributions):

# Start getty on tty3
systemctl start getty@tty3.service

# Or more permanently:
systemctl enable --now getty@tty3.service

During my recent RAID recovery, I used this sequence:

# Terminal 1 - Running RAID check
mdadm --detail /dev/md0

# Terminal 2 - Monitoring progress
watch -n 5 cat /proc/mdstat

# Terminal 3 - Editing configs
vim /etc/mdadm/mdadm.conf

• Some minimal recovery environments may not have agetty installed
• Certain distributions may require different service names (e.g., mingetty)
• Remember to background (&) the process or use screen/tmux if terminal multiplexing is preferred

During extended single-user mode operations like RAID reconstruction, system administrators often require concurrent shell access. While the primary TTY (usually tty1) runs critical recovery processes, additional terminals become essential for:

• Monitoring log files in real-time (tail -f /var/log/messages)
• Editing configuration files (vi /etc/mdadm.conf)
• Running diagnostic commands (mdadm --detail /dev/md0)

The most straightforward approach leverages existing virtual terminals:

# Spawn a new shell on tty2
sudo /sbin/agetty -n -l /bin/bash 38400 tty2 &

This command:

• Bypasses login prompt with -n
• Specifies bash as the shell with -l
• Sets baud rate (irrelevant for virtual terminals but required)

When TTY access isn't available, consider terminal multiplexers:

# For systems with screen installed
screen -S recovery_session

# Create new window: Ctrl+a c
# Switch windows: Ctrl+a n/p

For multi-day recovery operations, create a more robust solution:

# In /etc/inittab (SysV) or equivalent:
tty2::respawn:/sbin/agetty -n -l /bin/bash 38400 tty2

Permission denied errors: Ensure you're root in single-user mode. If encountering agetty limitations:

# Alternative using openvt
openvt -f -c 2 -- /bin/bash

Missing terminal switching: If Alt-Fn keys don't work, verify kernel VT support with:

dmesg | grep -i virtual