For many years, it was common for experienced system admins to manually customise kernels to enhance the performance, security and flexibility of Linux-based servers. Technological and hosting advancements, however, mean kernel customisation is no longer as relevant as it once was. In this post, we examine what a customised Kernel is and its advantages and disadvantages.
Contents
What is a customised kernel?
The kernel is the part of an operating system that acts as a link between the hardware and software and manages system resources. A customised kernel is one that has been reconfigured for specific purposes, such as to enable or disable features or optimise performance, security or compatibility.
Today, most service providers offer OS with kernels that are pre-optimised for general use; however, businesses running VPS, dedicated or bare-metal servers still have the option to customise them.
Why customise a kernel?
Despite technological advancements, there are still some practical reasons to customise kernels, especially those operating in specialised or high-demand environments. For instance, customisation can improve performance by removing unnecessary drivers, protocols or subsystems, making the kernel more efficient. This can speed up boot times and enhance responsiveness, especially when there are limited system resources.
A custom kernel can also improve security. Disabling unnecessary components reduces the potential for cyberattacks while enabling advanced security features can harden systems against threats. Similarly, by giving greater control over the system, customisation can potentially help with compliance for businesses In highly regulated industries.
Customisation can also increase flexibility, allowing admins to enable or disable experimental features, integrate hardware-specific modules or run legacy systems that may be incompatible with default kernel configurations.
Find out how to harden Linux security, read: The All-In-One Linux Server Security Tool
Challenges of custom kernels
Though they may offer advantages, custom kernels are more complex to manage. While standard kernels can be updated and patched by managed hosting providers, custom kernels have to be maintained manually. Admins will need to install security patches and manually recompile customisations following updates. They will also need to test new or updated configurations before deploying them.
While custom kernels may improve compatibility for some legacy systems, configuration changes may cause conflicts with other software, including control panels like cPanel or Plesk and proprietary applications and drivers. Poor configuration can prevent the system from booting and lead to downtime.
Businesses that wish to customise kernels and manage them afterwards will need considerable in-house expertise. IT teams will need to understand Linux kernel architecture and know how to work with configuration files, manage dependencies and troubleshoot issues.
Modern alternatives to customised kernels
Technological and hosting advancements mean there is far less need to customise kernels. For instance, some operating systems, such as CloudLinux and AlmaLinux, now have built-in tools that enable admins to fine-tune performance, improve isolation and harden security more easily.
Today, those with standard kernels can update them using live patching, a process that removes the need for server rebooting and thus increases availability. As customised kernels need to be recompiled and tested before going live, this makes customisation far less appealing to companies where the high availability of critical applications is essential.
Technologies like containerisation and virtualisation have also made customisation less relevant. Container tools, like Docker and Kubernetes, isolate workloads at the application or virtual machine level, reducing the need for customisation, while many cloud-native OS are now immutable and are not designed to be modified.
For more information about modern OS, read: CloudLinux or AlmaLinux: Which is the Best OS for Your Hosting Needs?
When does customisation still make sense?
While modern solutions have made customisation unnecessary in many circumstances, there are still some cases in which it can be beneficial. For example, businesses that develop hardware appliances or embedded systems may need to optimise the kernel for specific chipsets or devices.
Kernal customisation may also be advantageous for improving scheduling, interrupt handling and file system performance in environments that demand high-performance computing, such as in scientific research, AI modelling or real-time data analysis. Additionally, businesses with specific compliance needs or organisations operating in air-gapped environments may require customisation to achieve full control of the kernel. This may be necessary for auditing or accreditation purposes.
For more information on data security, read: Data Governance: Key Strategies for Business
Conclusion
While a customised kernel still has a role to play in some environments, for most server deployments, it is no longer essential. For the vast majority of businesses, especially those with a managed VPS, cloud server or dedicated server, the performance, security and reliability offered by today’s operating systems and hosting providers make customised kernels obsolete. That said, in highly specialised environments where control and optimisation are essential, customisation can still be advantageous. Businesses that choose to customise must understand the challenges it creates and have the expertise in place to manage those challenges.
A managed hosting provider, eukhost delivers exceptional performance, robust security and exceptional reliability across all our VPS, cloud and dedicated server environments, mitigating the need for custom kernels. As a provider of bespoke solutions, we also support clients with unique needs, including those who opt for kernel customisation. For more information about our hosting solutions and managed services, visit our homepage.
