1. Optimize CPU Scheduling for Better Performance

By default, Linux dynamically adjusts CPU scheduling, but you can 'tweak process priorities' to improve its performance.

Use nice and renice Use nice (which affects the process priority level) to start a process with a priority and renice to adjust it dynamically.

Start a process with a high priority (-10 means higher priority).

nice -n -10 ./my_script.sh

Change priority of an existing process (PID 1234)

renice -5 -p 1234

- 'Nice' values range from -20 (highest priority) to 19 (lowest priority). - Prioritizing critical workloads makes sure they get more CPU time. - Only root users can set negative nice values. - You could use ps -eo pid,comm,nice or top to find current priorities.

2. Increase File Descriptors to Handle More Open Files

By default, Linux limits the number of open files per process and for high-performance web servers or databases, this can be a bottleneck.

Solution: Adjust ulimit Check the current limit:

ulimit -n

- ulimit -n only affects the current shell session.

Increase the limit temporarily:

ulimit -n 100000

To make it persistent, edit /etc/security/limits.conf:

* soft nofile 100000
* hard nofile 200000

Applications like Nginx, MySQL, and Elasticsearch will now be able to handle more concurrent connections.

3. Enable TCP BBR for Faster Network Throughput

Linux's default TCP congestion control (CUBIC) may not be optimal for high-speed networks. BBR (Bottleneck Bandwidth and Round-trip propagation time) significantly improves network performance and reduces latency.

Solution: Enable TCP BBR Check the current congestion control algorithm:

sysctl net.ipv4.tcp_congestion_control

Enable BBR:

echo "net.core.default_qdisc=fq" >> /etc/sysctl.conf
echo "net.ipv4.tcp_congestion_control=bbr" >> /etc/sysctl.conf
sysctl -p

BBR significantly improves TCP performance, especially in cloud environments with high-latency or long-distance network connections..

4. Reduce Swappiness to Prevent Unnecessary Disk Swaps

By default, Linux starts using swap space aggressively, which can slow down performance.

Solution: Reduce Swappiness Check current swappiness:

cat /proc/sys/vm/swappiness

Reduce it (default is 60, lower values prefer RAM over swap):

echo "vm.swappiness=10" >> /etc/sysctl.conf
sysctl -p

With this, RAM is used efficiently before swapping to disk, which is much slower.

You can test it temporarily before making it persistent:

echo 10 > /proc/sys/vm/swappiness

5. Optimize Disk I/O Performance with noop Scheduler

For SSDs and cloud-based block storage, Linux's default I/O scheduler (cfq) isn't optimal because it was designed for spinning disk drives, not SSDs.

Solution: Use noop or deadline Scheduler Check current scheduler:

cat /sys/block/sda/queue/scheduler

Set to noop (ideal for SSDs):

echo "noop" > /sys/block/sda/queue/scheduler

For persistent changes, add this to /etc/default/grub:

GRUB_CMDLINE_LINUX="elevator=noop"

Then update Grub:

update-grub && reboot

Overall, it minimizes I/O latency and maximizes SSD performance.

6. Tune Network Buffers for High Traffic Applications

For high-throughput servers (e.g., Nginx, HAProxy), default Linux network buffers may be too low.

Solution: Increase Buffer Sizes

echo "net.core.rmem_max=16777216" >> /etc/sysctl.conf
echo "net.core.wmem_max=16777216" >> /etc/sysctl.conf
echo "net.core.netdev_max_backlog=5000" >> /etc/sysctl.conf
sysctl -p

Prevents packet drops and improves performance for high-bandwidth applications.

7. Enable HugePages for Faster Memory Management

HugePages reduce CPU overhead for memory-intensive applications like databases (PostgreSQL, MySQL).

Solution: Enable HugePages Check current HugePages status:

cat /proc/meminfo | grep HugePages

Enable HugePages (modify /etc/sysctl.conf):

echo "vm.nr_hugepages=1024" >> /etc/sysctl.conf
sysctl -p

This optimizes memory allocation and improves database performance.

8. Use tmpfs for Faster Temporary File Access

If your application reads/writes temporary files frequently, using tmpfs (RAM-based filesystem) is much faster.

Solution: Mount /tmp as tmpfs Edit /etc/fstab:

tmpfs /tmp tmpfs defaults,noatime,nosuid,size=2G 0 0

Mount it:

mount -a

This speeds up caching, builds, and temporary storage.

9. Optimize Systemd Services for Faster Boot and Performance

Some unnecessary background services consume CPU and RAM.

Solution: Disable Unused Services List services consuming boot time:

systemd-analyze blame

Disable unnecessary services:

systemctl disable bluetooth.service
systemctl disable cups.service

This frees up system resources, especially on minimal cloud VMs.

10. Enable CPU Frequency Scaling for Performance or Power Efficiency

Linux dynamically adjusts CPU speed, but you can manually optimize it for performance.

Solution: Use cpufrequtils Install CPU frequency utilities:

apt install cpufrequtils -y

Set CPU to performance mode (disables power-saving throttling):

cpufreq-set -g performance

For persistent changes, modify /etc/default/cpufrequtils:

GOVERNOR="performance"

Maximum CPU speed is used for high-performance workloads.

11. Use tuned for Dynamic System Performance Profiles

Linux systems can benefit from automated performance tuning using predefined profiles based on workload types (e.g., virtual hosts, databases, desktops). The tuned daemon dynamically adjusts system parameters in real-time to match the selected profile.

Solution: Install and use tuned

1. Install tuned: On RHEL/CentOS:

yum install tuned -y

On Ubuntu/Debian:

apt install tuned -y

2. Start and enable the service:

systemctl enable --now tuned

3. List available tuning profiles:

tuned-adm list

4. Apply a performance-optimized profile:

tuned-adm profile throughput-performance

5. Verify the active profile:

tuned-adm active

Some popular profiles include: - throughput-performance: Optimizes for network/disk throughput. - latency-performance: Ideal for low-latency applications like databases. - virtual-guest: Optimized for virtual machines. - balanced: General-purpose tuning.

11 Linux Networking Commands

important networking commands and their use cases.

medium.com

P.S. I recently released a DevOps Starter Kit , a bundle of 20+ Bash scripts, cron jobs, and Docker templates to speed up your infrastructure setup. If you do a lot of server work, you might find it useful.