Common problems

Things that can go wrong on a Linux server

Running a Linux server on the internet can be complicated, and many things can go wrong. Don't worry, we'll not only explain the common problems, but also show you how to diagnose and solve them.

• High load: A high load can cause system slowdowns and unresponsiveness, and can be caused by a number of factors such as malware, resource-intensive processes or bugs in software.

• High memory usage: When the running processes use a lot of the available RAM, it may not be possible to start additional applications. Even worse, if you run out of available memory, the kernel might kill one or more processes to free some memory.

• High I/O wait: If the CPU needs to wait for data from disk, the system may become very slow or unusable.

• Swapping: When the system runs out of memory, data is moved from RAM to disk to free up space. This causes the system to become very slow.

• Disk full: Running out of disk space can cause a variety of problems, such as preventing new files from being written or causing system crashes.

• Disk failing: SSDs can alert you, when they reach their end of life. Then it's time to react quickly to avoid data loss.

• RAID members inactive: When a drive is missing from a RAID array, you need to find a replacement to avoid data loss.

• Memory leaks: Memory leaks occur when a process continues to consume more and more memory over time, eventually causing the system to run out of memory.

• Network issues: Network issues can cause problems such as slow performance, intermittent connectivity, or complete loss of connectivity, which can be caused by a variety of factors, such as misconfigured network settings, hardware failures, or security breaches.

• File system corruption: File system corruption can cause data loss and system crashes, and can be caused by a variety of factors such as power outages, software bugs, or hardware failures.

• Security vulnerabilities: Security vulnerabilities can be exploited by attackers to gain unauthorized access to a system, steal data, or launch attacks on other systems.

• Malware infection: Malware infections can cause a variety of problems, such as data loss, system crashes, or unauthorized access to a system.

• Software bugs: Software bugs can cause a variety of problems, such as system crashes, data loss, or unexpected behavior.

• Hardware failures: Hardware failures can cause a variety of problems, such as system crashes, data loss, or unexpected behavior.

• Performance issues: Poor performance can be caused by a variety of factors, such as high load, resource-intensive processes, or software bugs, and can cause system slowdowns and unresponsiveness.

• Service or daemon crashes: Services or daemons can crash for a variety of reasons, such as software bugs, resource exhaustion, or configuration errors, and can cause system crashes or unresponsiveness.

• Incorrect configuration: Incorrect configuration of software or services can cause a variety of problems, such as system crashes, unexpected behavior, or poor performance.

• Firewall issues: Firewall issues can cause problems such as poor performance, unexpected behavior, or difficulty in accessing remote resources.

• Power issues: Power issues can cause problems such as system crashes, data loss, or unexpected behavior. This can happen due to power outages, hardware failures, or software bugs.

• Kernel issues: Kernel issues can cause problems such as system crashes, poor performance, or unexpected behavior. This can happen due to software bugs, hardware incompatibilities, or outdated kernels.

• Security breaches: Security breaches can cause problems such as data loss, unauthorized access, or system compromise. This can happen due to weak passwords, unpatched software, or malicious actors.

• Database issues: Database issues can cause problems such as poor performance, data loss, or unexpected behavior. This can happen due to software bugs, hardware failures, or incorrectly configured databases.

• Virtualization issues: Virtualization issues can cause problems such as poor performance, unexpected behavior, or difficulty in managing virtual machines. This can happen due to software bugs, hardware incompatibilities, or misconfigured virtualization settings.

• DNS issues: DNS issues can cause problems such as difficulty in resolving domain names, poor performance, or unexpected behavior. This can happen due to misconfigured DNS settings, network connectivity issues, or hardware failures.

• Email issues: Email issues can cause problems such as difficulty in sending or receiving email, poor performance, or unexpected behavior. This can happen due to misconfigured email settings, network connectivity issues, or software bugs.

• SSH issues: SSH issues can cause problems such as difficulty in connecting, poor performance, or unexpected behavior. This can happen due to misconfigured SSH settings, network connectivity issues, or software bugs.

• NTP issues: NTP issues can cause problems such as difficulty in synchronizing time, unexpected behavior, or poor performance. This can happen due to misconfigured NTP settings, network connectivity issues, or software bugs.

• Cron issues: Scheduling and Cron issues can cause problems such as difficulty in automating tasks, unexpected behavior, or poor performance. This can happen due to misconfigured scheduling settings, software bugs, or hardware failures.

• Permissions issues: Permissions issues can cause problems such as difficulty in accessing resources, unexpected behavior, or poor performance. This can happen due to misconfigured permissions settings, software bugs, or hardware failures.