Step 2: System Tuning

Kernel parameter optimization, system limits, and disk formatting.

Step 2: System Tuning

Standard Linux distributions are configured for general-purpose computing. Solana is a high-performance UDP-based protocol that pushes the OS to its absolute limits. We must manually override the kernel parameters to handle the massive volume of network packets and open file descriptors.

💡 Note: The Agave validator binary includes a solana-sys-tuner daemon that automatically adjusts some of these settings at runtime. However, it is still best practice to persist them in config files so they survive reboots. Always restart solana-sys-tuner after each software upgrade to ensure the latest recommended settings are applied.

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1. Optimize Kernel Parameters (sysctl)

We need to increase the UDP buffer sizes and memory map limits to accommodate the Solana Accounts Database.

A. Create the configuration file

sudo nano /etc/sysctl.d/20-solana-udp-buffers.conf

B. Paste the following configuration:

# Increase UDP Buffer sizes for high-volume gossip
net.core.rmem_max=134217728
net.core.rmem_default=134217728
net.core.wmem_max=134217728
net.core.wmem_default=134217728

# Increase memory map limit (Critical for Accounts DB)
# Allows the node to map the massive accounts database into RAM
vm.max_map_count=1000000

# Increase limit for open files (File Descriptors)
fs.nr_open=1000000

C. Apply changes

sudo sysctl -p /etc/sysctl.d/20-solana-udp-buffers.conf

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2. Configure User Limits (NOFILE)

Default Linux users are often limited to 1024 open files. A busy Solana node handles thousands of connections and file handles simultaneously.

A. Edit the limits configuration

sudo nano /etc/security/limits.d/90-solana-nofiles.conf

B. Paste the following:

# Increase process file descriptor count limit for solana user
solana soft nofile 1000000
solana hard nofile 1000000

# Increase memory locked limit
solana soft memlock unlimited
solana hard memlock unlimited

🔄 Action Required: You must close your current session and log back in for these limits to apply. Verify the change by running: ulimit -n (It should return 1000000).

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3. Disk Partitioning & Mounting

As discussed in Prerequisites, you should have separate NVMe drives for the Ledger (History) and Accounts (State). Using separate drives prevents I/O contention between read-heavy account queries and write-intensive ledger operations.

⚠️ Important: Use enterprise-grade NVMe SSDs exclusively. Consumer-grade drives will wear out or degrade quickly under Solana's sustained write workload.

A. Format Drives (EXT4)

Assuming your drives are /dev/nvme1n1 and /dev/nvme2n1:

sudo mkfs.ext4 -L LEDGER /dev/nvme1n1
sudo mkfs.ext4 -L ACCOUNTS /dev/nvme2n1

B. Create Mount Points

sudo mkdir -p /mnt/ledger
sudo mkdir -p /mnt/accounts

C. Configure Auto-Mount (fstab)

Edit the file system table to ensure drives mount on reboot with performance flags.

sudo nano /etc/fstab

Add these lines to the bottom of the file:

LABEL=LEDGER /mnt/ledger ext4 defaults,noatime,discard 0 0
LABEL=ACCOUNTS /mnt/accounts ext4 defaults,noatime,discard 0 0

• noatime: Disables writing "last access time" metadata (Saves IOPS).

• discard: Enables TRIM for SSD health.

D. Mount and Set Permissions

# Mount all drives
sudo mount -a

# Set ownership to the solana user
sudo chown -R solana:solana /mnt/ledger
sudo chown -R solana:solana /mnt/accounts

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4. CPU Performance Mode

Ensure your CPU is running at maximum frequency and not trying to save power.

# Install tools
sudo apt install -y linux-tools-common linux-tools-generic

# Set governor to performance
echo "performance" | sudo tee /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor

💡 Tip: To make the CPU governor persist across reboots, consider adding the command above to /etc/rc.local or creating a systemd service for it.

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✅ Checklist: Ready for Installation?

• [ ] sysctl parameters updated.

• [ ] ulimit -n returns 1,000,000.

• [ ] Drives mounted at /mnt/ledger and /mnt/accounts.

• [ ] Directories owned by user solana.

• [ ] CPU governor set to performance.