What is Server Monitoring?

If you want to know what server monitoring is, there are several definitions you can navigate. To put it simply, server monitoring is the systematic tracking, measuring, or observing of processes and operations on a server.

Its purpose is to use the collected data to draw conclusions about the health and condition of the server and ensure it reaches optimal performance.

What are servers?

Servers are central, indispensable elements of any IT environment. They provide hardware resources and functions to other systems and applications, and may be operated as on-premises hardware-only servers, cloud servers, or virtualized servers.

There are multiple servers out there. These may be distinguished, according to their purpose and uses, as database servers, web servers, e-mail servers, application servers, or file servers.

Depending on their type, the actual server monitoring process also differs. The need for different approaches makes it challenging. Each system requires different data that may be used to assess log files, event logs, and identify performance issues.

It is also necessary to have a good, clear context, so analyzing information may only be done in comparison with other key performance indicators generated, for example, from historical data.

Why is there a need for server monitoring tools?

Performing server monitoring tasks doesn't require an out-of-the-box approach. All it takes is structure.

When performed manually, this process is extremely dreadful, as it requires much time and a high level of resource utilization that could, otherwise, be put to more valuable use.

Identifying performance issues this way offers plenty of space to human errors and delays incident detection and response time.

System administrators need server monitoring tools that support them in this complex task, otherwise, the manual effort required for server monitoring is far too high and risky.

What happens when servers fail?

Servers enable the provision of various applications, services, and functions in the IT infrastructure and often take on critical tasks. Failure translates into difficulties for the company and the bottom line.

A slow or failed server quickly affects the entire IT infrastructure

One of the reasons why they are extremely important for organizations is that in networked environments, many other systems can be affected by the malfunction or overload of a server.

An inoperational server generates employee and customer dissatisfaction

When a server doesn't work to its maximum capacity, files or programs cannot be executed as usual. This disrupts user interaction, leading to employee and customer dissatisfaction. The result translates into inefficient work processes and customers who migrate to the competition where they are offered better digital interaction.

When servers fail, companies lose money

When employees can't perform their tasks, and customers can't complete their orders or generate the necessary conversions, companies lose income.

The inbuilt Checkmk dashboard for Linux servers

Why is server monitoring important?

A server monitor always helps ensure the performance and functionality of different servers (web servers, app servers, email servers), offering a series of benefits, such as:

Server monitoring helps you assess servers in real-time

By keeping track of key metrics, which are relevant for a well-working infrastructure, server monitoring tools enable you to assess the health and performance of your servers in real-time. This way, you can always provide the necessary maintenance to keep things working in the best parameters.

Server monitoring software contributes to identifying bottlenecks

A metric that is out of range is a symptom of a potential issue. A good server monitoring system helps you identify bottlenecks so that you can solve them before they escalate.

Server monitoring contributes to an automated, error-free environment

A reliable server monitoring solution will take on time-consuming tasks by automating processes and making checks on its own. The extra layer of automation it brings ensures system administrators don't have to check log files on their own and reduces the risks of human errors.

Server monitoring contributes to security management

No matter if we are talking about a web server or any other type, infrastructure monitoring plays an important part in security orchestration. When using a security tool, IT managers have a better understanding of a company's security posture.

Server monitoring tools optimize resources

A high level of automation translates into optimization. Resources are used better, more efficiently and people may focus on the tasks where they make a difference, instead of using their time to collect and analyze data.

A good server monitoring tool keeps stakeholders happy

A server that works makes employees and customers happy because it offers them a smooth end-user experience.

How does server monitoring work?

To ensure smooth operation, server monitoring tools must be specifically adapted to the server's purpose. Depending on each server type, in addition to performance data – such as CPU usage, disk usage, memory, storage utilization, and network servers connection – additional information on other applications, services and processes must be included in the infrastructure monitoring.

For a file server, for example, this is different data than for a web server. In addition, the server monitoring tool requirements differ if the server is physical or virtual.

A dedicated strategy focuses on certain key performance indicators and server monitoring capabilities that make the process an extremely reliable, trustworthy one.

What happens when the server monitoring software detects system errors?

The server monitoring tool used should alert the responsible system administrator if an error or problem occurs so that they can react immediately.

Once the right people are informed, the procedure should be applied. This includes approaching the department or professionals that should identify a solution.

When using server monitoring tools, it is also possible to predict developments based on historical data and anticipate possible bottlenecks in the future, for example in storage capacities, and take appropriate countermeasures.

Dashboard in Checkmk showing vSphere servers

What is a virtual server?

While a typical server is most often a physical machine running an operating system and one or more server applications, a virtual server (VS) is detached from the hardware.

By abstracting from the hardware layer, multiple virtual servers running typically as virtual machines (VMs) can share the underlying hardware. Hardware resources can be dimensioned as needed for each VM and used more efficiently. This is often done via a hypervisor, which distributes the hardware resources such as CPU usage, disk usage/disk space, RAM, and hard disk space among the VMs.

What do virtual servers bring to the table?

One big advantage of virtual servers is that hardware resources can be added remotely. Just as with physical servers, the operating system and applications can also be managed centrally.

Furthermore, it is possible to adapt them to current developments by scaling them to deal with performance peaks – or to readjust the allocated hardware resources to lower performance requirements.

What are the minuses of virtual servers?

Virtual servers also come with their counter benefits. Their monitoring is more complex, since the hypervisor or virtualization platform, the virtual machine, and the underlying hardware have to be mapped as several dependencies in the server monitor process. This is the only way to identify all the interdependencies and correctly locate the causes of problems.

Security events must also be taken into account.

What is server management?

Monitoring is often seen as part of server management. However, server management also includes the regular application of updates and security patches, the installation of new devices, and the correction and elimination of problems.

It also keeps track of the provision of sufficient resources for the daily requirements. Planning of server capacities, for example, is part of it.

How does server monitoring simplify server management?

Excluding the setup of new systems, a powerful server monitoring tool can support all these described server management tasks.

In addition to monitoring the health and performance of systems and identifying problems, server monitoring can provide information about the server's hardware and installed software and their patch levels, depending on data availability.

This makes it possible to see when updates or patches have not yet been installed on a system.
By comparing this with historical monitoring data, trends and developments can also be read for the future. This information is in turn useful for capacity planning.

Customized dashboard in Checkmk for monitoring server performance

How do I monitor server performance?

Server performance monitoring is not as broad a monitoring approach as monitoring is. Instead, the focus is strictly on monitoring performance metrics.

In the case of a physical server, for example, these are CPU utilization, memory consumption, disk I/O, and network performance. However, depending on the server type, performance monitoring focuses on different metrics, such as response time for a web server or the network bandwidth utilization for a backup server.

Using server monitoring tools for performance also allows conclusions to be drawn about potential performance problems, such as when loads have reached a critical point after implementing a new application. Furthermore, it can also support capacity management, for example, discussing the resource requirements of new workloads.

Server performance metrics can also be used to verify SLAs, such as whether servers were available for the specified time while providing the required performance.

What is open-source monitoring?

Open-source monitoring is an open-source-based monitoring solution that often includes other open-source tools or the use of Linux.

However, when it comes to monitoring the IT infrastructure, these solutions are not limited to Linux servers, but can usually monitor all commonly used operating systems.

Open-source also allows users to view, change or distribute the underlying code.

What kind of monitoring systems are available?

As with any other software, monitoring systems also come in the usual variations:


This monitoring solution is installed on a separate system in the IT infrastructure or connected to the network servers as a hardware appliance. Depending on the server monitoring tool and the devices to be monitored, the configuration effort can vary.

However, this customizability of the solution does not have to be a disadvantage.
In addition, with an on-premises solution, you retain control over your data, since it is also stored on-site.


In contrast to the on-premises option, some server monitoring tools can be obtained as a service from cloud providers. In this case, configuration and administration are usually managed via a web interface.

Since no software has to be installed on the company's server infrastructure, the installation is often relatively quick.

The advantage of the SaaS variant is that these are usually good for monitoring cloud and microservice infrastructures and are distributed via a subscription, which can also be flexibly canceled.

However, it becomes more difficult when a company needs to monitor IT assets in the cloud and on-premises. Transferring the monitoring data of these systems to the cloud often involves additional configuration effort. Data transfer to the cloud also results in higher costs.

Especially when monitoring SNMP devices, large amounts of data are generated that have to be transferred to the cloud. 
At the same time, one should be aware that with a cloud solution, the monitoring data is located with a third-party provider, which may violate data protection guidelines.

Mobile applications

In general, monitoring systems are not provided as mobile applications.

However, it is more common for manufacturers of monitoring tools to offer their users access to dashboards and monitoring data via a mobile application. These often have fewer functions than the user interface of the PC version, though.

Customized dashboard in Checkmk showing relevant data

What are the best practices for server monitoring?

Monitoring is a complex topic. Depending on the server landscape, there are different things to consider for holistic monitoring. However, there are some generally applicable tips that absolutely belong in monitoring, regardless of the IT infrastructure to be monitored:

Putting monitoring data in the right context

Without having comparative metrics, it's difficult to know if a server's behavior is unusual. It may be that CPU utilization at the time is not unnatural because the server is rolling out important updates. So it is always important to be able to put the data into the right context.

Only then, correlations between different components can be identified even over longer periods of time – and problems can be identified at an early stage and ideally eliminated in advance.

Using monitoring for capacity planning

Comparing monitoring data over a longer period of time also allows conclusions to be drawn about future developments. For example, it is possible to predict how storage space will develop over time with normal usage or whether CPU utilization is still in the healthy range. Long-term monitoring of servers enables administrators to react to the needs of their servers at an early stage.

Using precise alerts

Good monitoring only helps if the administrator immediately receives a notification should a critical threshold value be undercut or exceeded or a problem occurs.

The alerting must be configurable in such a way that, on the one hand, only the responsible person receives a notification and, on the other hand, only when there is a real need for action.

Otherwise, there is a risk that a critical alarm will be lost in the flood of less important notifications. At the same time, the monitoring tool should allow different ways of communication, for example via e-mail, call, SMS, or messenger.

Asset management for servers

Monitoring should also provide an inventory of all installed hardware and software on the server. This makes it possible to immediately identify defective or modified hardware, such as missing hard disks or defective memory blocks. The same applies to the software on the server.

An inventory helps detect newly installed software and its version, or to track changes to the operating system or updates to applications.

Available information about the software in use can also be transferred to a license management system, for example. In addition, some monitoring solutions benefit from network connectivity, as they can be connected to a configuration management database (CMDB) and the data of the monitored systems can be transferred directly to it.

What features must the best server monitoring tool have?

Screenshot of the Main Dashboard of Checkmk

Broad coverage

For the monitoring tool to get the data it needs, it must be able to retrieve it from the server. Therefore, it is necessary that the solution supports all commonly used operating systems and monitors all services. Furthermore, the solution must support both virtual and on-premises systems.

Intelligent alarm management

Another point is easily configurable alarm management. This includes the setting of sensible thresholds and the method of notification should an error or warning occur.

Extensive root cause analysis

For a server to function, several areas interact: the hardware and operating system layers, as well as the application layer. A good monitoring tool not only indicates that a problem is occurring but also offers the possibility of viewing the problem in context, in which it represents certain dependencies, for example.

Ease of use

The true value of a solution is directly related to its usability. For a monitoring solution, it is important that the software is easy to use and also provides powerful dashboards for visualizing the monitoring data. This makes it possible to see all important areas of a server at a glance and to react immediately to errors or problems.

Support policy

Support is an important issue, especially in the enterprise field. Therefore, in the decision-making process, you should always check how easy it is to contact support in the event of problems.

Security orchestration should be taken into account, as it is important to ensure that measures are taken to prevent challenges like data loss or cybersecurity threats.

Dashboard in Checkmk for monitoring a web server

Server monitoring is essential for IT operations

Servers are among the most important components of a company's IT infrastructure. As soon as a server fails or only functions to a limited extent, the effects are usually immediately felt elsewhere, for example, because certain services fail or response times are significantly longer.

The result is not only inefficient employees, but also dissatisfied customers looking for an alternative.

It is therefore logical that monitoring server performance and health is in the IT team's best interest. Comprehensive and consistent server monitoring also helps them not only identify current problems, but proactively prevent incidents in the future.

Server monitoring with Checkmk for scalable infrastructures

Checkmk is an all-in-one monitoring solution that lets you monitor thousands of servers with a single instance. Due to its distributed monitoring capability, it can easily scale horizontally to let you monitor even larger infrastructures.

Checkmk supports the monitoring of almost every operating system such as Linux, Windows, macOS, but also many other OSes like BSD.