How to Diagnose and Fix Slow Boot Times in Arch Linux

Diagnose Boot Performance with systemd-analyze

Start by understanding where time is being spent during your boot process using these essential commands:

Example output interpretation:

Startup finished in 8.075s (firmware) + 3.495s (loader) + 1.414s (kernel) + 1min 30.309s (userspace) = 1min 43.295s

This shows the userspace phase is the main bottleneck at 1 minute 30 seconds.

Common Slow Boot Issues and Solutions

Service Conflicts and Timeouts

Multiple Network Managers: Having conflicting services like systemd-networkd, iwd, dhcpcd, and netctl enabled simultaneously causes delays. Choose one and disable the others.

Slow Services: Use systemd-analyze blame to identify services taking excessive time. Consider delaying non-essential services or using socket activation.

Socket Activation for Heavy Services

For services like Docker that significantly impact boot time, replace direct service startup with socket activation:

sudo systemctl disable docker.service
sudo systemctl enable docker.socket

This starts Docker only when first needed, removing it from the critical boot path. One user reported boot time reduction from 68 seconds to 28 seconds using this method.

Hardware-Specific Issues

Slow Kernel Time: If kernel phase takes >10 seconds (like 33s in one case), this may indicate storage or hardware issues. Check for AMD GPU timeout messages or storage controller problems in journalctl logs.

Wait for Network: Services like systemd-networkd-wait-online.service can delay boot. Consider if your system truly needs full network connectivity before boot completion.

Optimization Checklist

Apply these additional optimizations for better boot performance:

• Review Enabled Services: Disable unnecessary services with systemctl disable service.name
• Kernel Parameters: Add libahci.ignore_sss=1 to disable staggered spin-up on some hardware
• Filesystem Mount Options: Use noauto,x-systemd.automount for non-critical filesystems like /home to mount on first access
• Initramfs Optimization: Consider slimmer alternatives like Booster or mkinitcpio with systemd hook instead of base and udev
• UEFI Firmware: Update your motherboard BIOS/UEFI, as slow firmware initialization contributes to boot time

Putting It All Together: A Real-World Example

Here's how one user solved their 1 minute 43 second boot time:

1. Identified the Culprit: systemd-analyze critical-chain showed network.target waiting over a minute
2. Discovered Root Cause: Multiple conflicting network services (iwd, dhcpcd, systemd-networkd)
3. Applied Fix: Consolidated to a single network management solution
4. Verified Improvement: Boot time reduced significantly after resolving conflicts

After applying the relevant optimizations for your system, run systemd-analyze again to compare results. Most systems can achieve 15-30 second boot times with proper tuning.

If you're still experiencing specific issues after trying these