Nagios Core 4.5.9 on CentOS 10

My main use case for Nagios Core on CentOS  is to monitor remote servers and configure alerting. I use default plugins available in NRPE to monitor Linux instances and other running services. I created custom plugins to monitor Docker  containers and the processes running inside them, all monitored through Nagios.

The way I set up Nagios Core on CentOS  is unique because I monitor Docker  containers at a granular level. If any processes, such as Python microservices, exit, I receive alerting to Google Chat and email. A separate team works with me to continuously monitor for alerts and inform respective team members to quickly investigate and resolve problems.

The best features of Nagios Core on CentOS are complete infrastructure monitoring and real-time alerting and notifications. The plugin-based architecture allows me to create custom plugins, and the centralized dashboard provides comprehensive visibility. Nagios Core on CentOS has positively impacted my organization by significantly reducing downtime through timely alerts configured according to my specifications. It has provided centralized visibility across all infrastructure. I monitor many instances using Nagios and find it highly customizable for my use case.

Nagios Core on CentOS could be improved with an official Docker image from Nagios Core . Currently, I created my own Docker image and use it by mapping volumes to the Linux host. Having an official Docker image with a compose file or the ability to deploy into a Kubernetes  environment would be beneficial.

I would like to add feedback regarding the interface. If the interface could be made more similar to Grafana  for checking historical data, that would be valuable. I already have the data available but must view it in log form. Making it more similar to Grafana  would be helpful, though I understand this requires consideration from a product perspective. Overall, the solution looks good to me.

I have been using Nagios Core on CentOS for the past five years.

In my experience, Nagios Core on CentOS is very stable and continues to function well.

Regarding Nagios Core on CentOS's scalability, it is currently running on a single instance. I do not need to scale it extensively, and it runs stably in its current configuration.

I have not needed to contact customer support, but I hope the service is good.

Before switching to Nagios Core on CentOS, I used a different solution to obtain more aggressive alerting for custom services.

Nagios Core on CentOS is deployed in my organization in a public cloud rather than directly on a host. It is deployed using a Docker image and containers in a dockerized environment. My experience with the open-source version was straightforward, and deploying it through a Docker image made the process easier. I created a custom Docker image that helps new team members deploy Nagios Core on CentOS in different environments.

A separate team works with me on Nagios Core on CentOS implementation. We continuously monitor for alerts, and when an alert occurs, the team informs respective team members to quickly investigate and resolve the problem.

I have seen a return on investment in terms of saving time. Any downtime or service failure results in time savings. Regarding specific outcomes or metrics on reduced downtime, before monitoring was fully in place, issues were often detected late. With proactive alerts, unplanned downtime dropped by around thirty to forty percent.

Regarding pricing, setup cost, and licensing, I used the open-source version, so the setup cost is zero and no license is required. This made it easy for me to deploy Nagios Core on CentOS.

Before choosing Nagios Core on CentOS, I evaluated other options including Grafana, but later switched to Nagios Core on CentOS.

My advice to others looking into using Nagios Core on CentOS is to definitely go for it. It is very good and I appreciate the alerting mechanism. I provide this review with an overall rating of eight out of ten.

I used Nagios Core on CentOS  at my previous company, Infosys, for three years. My main use case for Nagios Core on CentOS  was monitoring servers. I used Nagios Core on CentOS as a monitoring server to monitor both Linux and Windows environments, and the setup was plugin driven where we configured host and service checks for CPU, memory, disk usage, and critical services such as SSH, HTTP, and database processes.

Nagios Core on CentOS was very effective in proactive monitoring, with its strengths lying in early alerting and flexibility through plugins, which helped us detect issues before they impacted users.

The biggest strength of Nagios Core on CentOS is its plugin architecture, which is extremely flexible because plugins are scripts or binaries that return a standard output and exit code. This means we can monitor almost anything, including system metrics, applications, APIs, or even custom business logic.

The flexibility of Nagios Core on CentOS plugins is one of the biggest advantages, allowing companies to extend monitoring beyond standard infrastructure into application and business-level monitoring.

Using Nagios Core on CentOS had a significant positive impact on the organization at Infosys where I used it by improving system availability, reducing downtime, and enabling proactive issue resolution. Nagios Core on CentOS helps organizations detect issues before they become outages. We were reaching out after users reported issues before; with Nagios Core on CentOS, we identified problems before users even noticed them. Automated alerts ensured the right team was notified immediately, and it worked very well for the organization.

Manual monitoring efforts were reduced, allowing the team to focus on improvement instead of constant checks. While Nagios Core on CentOS provided strong monitoring capabilities, it requires manual configuration and maintenance, which need proper planning and standardization in large environments. Nagios Core on CentOS transformed monitoring from reactive to proactive, improved system reliability, and helped the organization maintain better uptime and performance, reducing critical incidents by approximately twenty to thirty percent after implementing proactive monitoring.

Nagios Core on CentOS is very stable and reliable, but it can be significantly improved in terms of automation, scalability, and usability. Most improvements for Nagios Core on CentOS revolve around reducing manual efforts and modernizing the ecosystem.

Automating Nagios Core on CentOS configuration reduces human error and improves consistency across environments. Visualization is a major gap here, as modern tools provide much better dashboards compared to Nagios Core on CentOS.

For large environments, scaling Nagios Core on CentOS requires additional architectural planning, and tuning alerts is critical; otherwise, teams start ignoring notifications. Integration of performance metrics helps move from reactive to predictive monitoring, but having too many custom plugins makes it hard to maintain.

Nagios Core on CentOS is extremely powerful and flexible, but it requires effort to modernize with automation, better visualization, and a scalable architecture. It can still be very effective compared to newer monitoring tools, and it could benefit from a UI with tools such as Grafana , implementing distributed monitoring for scalability and fine-tuning alerting to reduce noise. These kinds of improvements would make it more efficient and easier to manage in large environments.

Nagios Core on CentOS is strong technically but needs ecosystem improvement to match modern observability tools.

I used Nagios Core on CentOS in my previous company, Infosys, and I used Nagios for three years.

Nagios Core on CentOS is stable and reliable, especially for long-running monitoring environments, but due to UI issues, we are moving to Grafana .

Nagios Core on CentOS is moderately scalable, working very well for small to mid-size environments, but scaling to large environments requires additional architecture and planning.

For Nagios Core on CentOS, customer support is community-driven rather than vendor-driven. Since it is an open-source product, support is good but not instant compared to enterprise tools. I was not entirely satisfied with the customer support, but it is acceptable because it is community-driven.

Before moving to Nagios Core on CentOS, we were using basic monitoring tools such as manual checks and simple scripts, and in some areas, we also evaluated tools such as Zabbix  and SolarWinds. Ultimately, we decided to move to Nagios Core on CentOS, and recently, we moved to Grafana because the UI is much stronger there.

We definitely see a positive ROI using Nagios Core on CentOS, as while it does not have licensing costs, the real return came from reducing downtime, faster issue resolution, and improved operational efficiency.

Nagios Core on CentOS has no licensing cost since it is open-source; however, there are indirect costs related to setup, maintenance, and scaling.

Before finalizing Nagios Core on CentOS, we evaluated several other monitoring tools such as Zabbix , Prometheus, and in some cases, SolarWinds.

If you are considering Nagios Core on CentOS, then treat it as a powerful but hands-on tool. You will get great reliability and flexibility, but you need to plan for setup, automation, and maintenance from day one. For a mid-size or small size infrastructure, Nagios Core on CentOS is a good option; for a large infrastructure, consider other tools. I rate this product as a six out of ten.

My main use case for Nagios Core on CentOS  is due to the enterprise platforms we run that are based solely on open source; for our R&D division, we need to use CentOS . Wherever we are using CentOS  and Ubuntu , we are using Nagios Core on CentOS  for monitoring.

I monitor all our server devices as a server and storage administrator through Nagios Core on CentOS, especially for server administration; all hardware level monitoring and OS level monitoring will be pushed into Nagios Core on CentOS, where we want to see the CPU memory usage or network usage.

In terms of my main use case with Nagios Core on CentOS, when we run any high load or high workload usage, Nagios Core on CentOS will be very helpful because we can check the current load usage of the system, processes running, causing bottlenecks, and network usage.

The best features Nagios Core on CentOS offers include systems usage, specifically the load average, and while the CPU and memory usage graphs are not displayed in a granular way, they are useful for analyzing trends and history, and I can create host groups for monitoring to check the entire cluster's usage.

Host group monitoring helps me in my daily work because we have a lot of divisions, so we cannot add all the hosts into a single group; we create host groups to segregate based on R&D, production, testing platform, and development platform.

Regarding features, I have tried the application monitoring feature, which is not that great but still useful; for open source, it is very helpful, though there are improvement areas in the application side. For server monitoring, especially, it is very good, while a few things are lagging in storage.

Nagios Core on CentOS has positively impacted my organization by being very helpful budget-wise, as we rely on open source due to budget constraints for each division.

I believe Nagios Core on CentOS can be improved mainly by the granularity of the metrics; while most enterprise metrics are available, some complex ones are missing, and it would be beneficial to integrate more APIs for better data granularity, which newer users struggle to see.

Regarding needed improvements, at this stage it is better, and I do not think any new things are required.

I have been using Nagios Core on CentOS for around seven to eight years.

Nagios Core on CentOS is stable.

Currently, we have not integrated Nagios Core on CentOS with other tools; it is a separate platform, and while we use other monitoring tools, there have been no integrations.

The customer support for Nagios Core on CentOS is almost equal to that of enterprise solutions.

Previously, we used ManageEngine, which was not that great, prompting our switch to Nagios Core on CentOS for its open source nature and similar features without additional costs.

I faced no major challenges during the setup or use of Nagios Core on CentOS, aside from low-level users struggling during installation; we created knowledge base articles to assist, so now we are not facing issues, although there was some initial struggle.

We handle alerting and notifications with Nagios Core on CentOS by enabling notifications to email IDs, triggering alerts to our separate monitoring NOC team that checks emails and diverts alerts to the respective team.

For Nagios Core on CentOS, we manage configuration and updates manually, but we are planning for automation.

We ensure security and access control for Nagios Core on CentOS by fixing all security vulnerabilities on time; our Linux admin team continuously monitors Linux devices, including Nagios Core on CentOS servers, and addresses any software level vulnerabilities.

I estimate cost savings of almost fifty thousand dollars per year thanks to using Nagios Core on CentOS.

The main factors that influenced my decision to choose Nagios Core on CentOS over other monitoring solutions are mainly its free of cost, open source nature, which saves a lot of money, and it being easy to install, so even junior staff can set it up straight away to start monitoring.

Before choosing Nagios Core on CentOS, we evaluated other options, including VMware's vROps and Prometheus with Grafana , but Nagios Core on CentOS received positive feedback for being user-friendly and widely used, which led us to select it.

My advice for others considering Nagios Core on CentOS is to focus on cost savings since organizations globally are cutting costs.

My additional thoughts on Nagios Core on CentOS include that certain metrics could be improved or added; however, ninety percent of them are already available. I would rate this product an eight out of ten.