As a Linux system administrator working with RHEL 6, I recently needed to debug a boot issue but found myself staring at the Plymouth splash screen instead of the valuable boot messages. Here's how I solved this common problem that many developers face.

The solution is simpler than you might think. During boot when the splash screen is visible:

1. Press the ESC key to toggle between splash screen and text output
2. Alternatively, use Left Arrow or Right Arrow keys to scroll through messages

For developers who need constant access to boot messages, consider disabling Plymouth entirely:

# Edit grub configuration
sudo vi /etc/default/grub

# Find and modify this line:
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

# Change it to:
GRUB_CMDLINE_LINUX_DEFAULT=""

# Update GRUB
sudo update-grub

If you missed the boot messages, you can still access them after the system starts:

# View complete boot log
dmesg

# Or check the systemd journal
journalctl -b

Last week I was troubleshooting a failed filesystem mount. Using the ESC key during boot revealed the error message:

[FAILED] Failed to mount /data - Check filesystem
[  OK  ] Reached target Basic System

This immediate visibility saved hours of guesswork compared to waiting for the system to boot and then checking logs.

For serious kernel debugging, you might want to create a custom boot entry with maximum verbosity:

# Add this to /etc/default/grub
GRUB_CMDLINE_LINUX_DEBUG="ignore_loglevel debug earlyprintk=vga,keep log_buf_len=16M"

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When working with RHEL 6, developers often need to debug boot issues or analyze system initialization. The default graphical splash screen can hide important boot messages that reveal hardware detection, service startup, and potential errors.

During system startup, RHEL 6 displays a Plymouth graphical splash screen by default. Behind this interface, the kernel and init system continue to output valuable diagnostic information to the console. These messages are critical for:

• Troubleshooting hardware compatibility issues
• Debugging service startup failures
• Analyzing system initialization timing
• Monitoring kernel module loading

To view these messages, you have several options:

Method 1: Temporary View During Boot

Press any of these keys during the splash screen:

ESC
Left Arrow
Right Arrow
Up Arrow
Down Arrow

This will temporarily disable Plymouth and show the text console output.

Method 2: Permanent Configuration Change

To permanently disable the splash screen, edit the kernel boot parameters:

# Edit /etc/default/grub
GRUB_CMDLINE_LINUX="rhgb quiet" → GRUB_CMDLINE_LINUX=""

Then regenerate the GRUB configuration:

grub2-mkconfig -o /boot/grub2/grub.cfg

Method 3: Viewing Boot Logs After Startup

You can examine boot messages after the system starts using:

dmesg | less
journalctl -b
cat /var/log/boot.log

For developers who need both splash screen and debug access, consider modifying Plymouth configuration:

# Edit /etc/plymouth/plymouthd.conf
[Daemon]
Theme=text
ShowDelay=0

Here's how viewing boot messages helped solve a network interface problem:

[    3.456789] e1000e: Intel(R) PRO/1000 Network Driver
[    3.456790] e1000e: Copyright(c) 1999-2015 Intel Corporation
[    3.456791] e1000e 0000:00:19.0: enabling device (0000 -> 0002)
[    3.456792] e1000e 0000:00:19.0: Interrupt Throttling Rate (ints/sec) set to dynamic conservative mode

This output revealed the driver was loading but not initializing properly, leading us to check the hardware connection.

Mastering boot message access in RHEL 6 is essential for system developers and administrators. Whether you need temporary visibility during troubleshooting or permanent configuration changes, these techniques provide the insight needed to maintain stable systems.