Storage Selection and SD Card Guidelines

Choosing the right SD card is essential for reliable Pimeleon router operation. This guide covers requirements, specifications, and best practices applicable to all deployments.

SD Card Requirements Overview

Pimeleon router requires an SD card for the operating system, application code, and runtime data. Unlike typical computer usage, router deployments have unique storage demands:

• Continuous write activity from logging and metrics
• 24/7 operation puts stress on storage components
• Reliability is more important than performance
• Card degradation has direct impact on uptime

Configuration Levels

Minimum Configuration

When budget is constrained:

• Capacity: 16GB
• Speed: Class 10 or higher
• Brand: Reliable manufacturer (SanDisk, Samsung)

Considerations:

• May require aggressive log rotation
• Limited space for detailed logging
• Functional but with operational constraints
• Not recommended for production use

Recommended Configuration

Balanced option for most deployments:

• Capacity: 32GB
• Speed: UHS-I (Ultra High Speed)
• Performance Class: A1
• Endurance rating: High endurance preferred

Advantages:

• Adequate space for normal logging
• Good performance characteristics
• Reasonable price-to-value ratio
• Suitable for typical production deployments
• Established track record for reliability

Use this configuration for: Home networks, small offices, and standard deployments.

Professional Configuration

Maximum reliability for critical deployments:

• Capacity: 64GB or larger
• Speed: UHS-I or UHS-II
• Performance Class: A2 or higher
• Endurance rating: Industrial or High Endurance
• Memory type: MLC (Multi-Level Cell) preferred over TLC

Advantages:

• Extensive logging capacity
• Superior reliability characteristics
• Industrial-grade durability
• Extended lifespan
• Professional support

Use this configuration for: Enterprise deployments, mission-critical systems, and high-load scenarios.

Understanding SD Card Specifications

Card Speed Classifications

Class 10:

• Minimum write speed: 10 MB/s
• Suitable for router applications
• Standard specification

UHS-I (Ultra High Speed):

• Theoretical bandwidth: 104 MB/s
• Better sustained performance
• Recommended for continuous operation

UHS-II:

• Theoretical bandwidth: 312 MB/s
• Highest performance level
• Not necessary for router applications but provides headroom

Performance Classes

Application Performance Class A1:

• 4K random read: 1500 operations/second
• 4K random write: 500 operations/second
• Optimized for application loading and execution
• Excellent for router deployments

Application Performance Class A2:

• 4K random read: 2000 operations/second
• 4K random write: 2000 operations/second
• Better sustained performance
• Ideal for heavy continuous usage

Endurance Ratings

Standard Endurance:

• Suitable for general-purpose use
• Limited write cycle lifespan
• Adequate for light to moderate logging

High Endurance:

• Designed for sustained write operations
• 2-3x lifespan of standard cards
• Recommended for router deployments

Industrial/Professional Endurance:

• Maximum reliability and lifespan
• Can withstand extreme conditions
• Best for mission-critical systems
• Highest durability investment

Brand Recommendations

Recommended Brands

SanDisk:

• Excellent Linux compatibility
• Wide variety of capacity/performance options
• Product variants: Extreme, Ultra, High Endurance
• Proven track record in Pi communities

Samsung:

• Consistent quality and reliability
• Good long-term track record
• Product variants: EVO+, PRO+
• Widely available

Brands to Avoid

Generic no-name brands:

• Higher failure rates
• Inconsistent quality control
• Poor documentation
• Limited support

Extremely budget options:

• Often counterfeit or refurbished
• Unreliable performance
• Risk of data loss
• False capacity claims

Thermal Considerations for Storage

Managing SD Card Heat

SD cards generate minimal heat compared to other components, but:

• Long-term reliability decreases with sustained high temperatures
• Ambient temperature affects card lifespan
• Cards in enclosed cases may experience higher temps
• Monitoring overall system temperature protects storage

Best Practices

• Ensure adequate case ventilation around card slot
• Avoid placing router in hot environments
• Monitor system temperatures regularly
• Replace cards proactively if temperatures run hot

Practical Selection Process

Step 1: Determine Capacity Needs

Consider your logging requirements:

• Network logs: 10-50 MB per day (depending on volume)
• Application logs: 5-20 MB per day
• Temporary files and cache: 100-200 MB
• OS and application: 2-3 GB

Example: 32GB card provides approximately 25-30GB usable space, allowing 500+ days of typical logging before recycling is needed.

Step 2: Choose Performance Class

For router applications:

• A1 is sufficient for most deployments
• A2 provides margin for future growth
• Both are widely available and reasonably priced

Step 3: Select Endurance Level

Based on expected deployment duration:

• Standard endurance: Temporary installations or test systems
• High endurance: All production deployments
• Industrial endurance: Critical systems or heavy-load scenarios

Step 4: Verify Availability and Support

• Check availability from authorized distributors
• Verify warranty terms
• Confirm Linux driver support
• Read recent reviews from Pi users

Purchasing Recommendations

Where to Buy

Authorized distributors:

• Amazon (verify seller reputation)
• Newegg
• B&H Photo
• Local electronics retailers

Avoid:

• Unknown online sellers
• Suspiciously low pricing
• Units without proper packaging
• No-questions-asked returns policies

Verification Tips

• Check product packaging for signs of tampering
• Verify capacity on first boot
• Test performance with known tools
• Keep original packaging for warranty claims

Storage Maintenance

Operational Considerations

Log rotation:

• Implement log rotation to prevent filling card
• Keep 2-4 weeks of logs instead of permanent history
• Balance with troubleshooting needs

Regular backups:

• Periodically backup card contents
• Useful for system recovery
• Easier than full OS reinstallation

Proactive replacement:

• Track card age (every 3-5 years)
• Replace before failure
• Unexpected card failure causes immediate downtime

Troubleshooting Storage Issues

Symptoms of SD Card Problems

• Random system reboots
• File system corruption
• Slow performance
• Boot failures
• Input/Output errors in logs

Quick Checks

# Check file system health
fsck /dev/mmcblk0p2

# Monitor disk usage
df -h

# Check I/O errors
dmesg | grep -i "mmc"

When to Replace

• Frequent I/O errors
• File system corruption
• Consistently high error rates
• Card approaching end of lifespan
• Performance degradation

Related Documentation

• Cooling - Thermal management for all components
• Power - Power supply specifications
• Accessories - Complete component list

Bottom Line: Choose a 32GB UHS-I A1 card from a reputable brand (SanDisk or Samsung) for most deployments. Invest in High Endurance cards for production systems. Replace cards proactively based on age and observed performance, not just failure. Good storage selection prevents data loss and maximizes uptime.