Learn the troubleshooting steps for resolving the ‘access denied’ error that root receives when using systemctl on Linux.
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Baeldung Author
Ismail Ajagbe
Tech Writer by day, DevOps Wizard by night, spinning digital yarns and deploying cloud spells đ.
Here's what I've written (so far):
Baeldung on Linux
- All
- Administration (27)
- Networking (11)
- Filesystems (11)
- Security (9)
- Processes (9)
- Building (6)
- Web (2)
- Installation (2)
- Scripting (1)
- Files (1)
- Docker (1)
How to Resolve vsftpd Unable to Read Config File
Filed under Administration, Networking
Learn how to resolve the ‘unable to read config file’ in vsftpd by going through various troubleshooting steps.
Conflicting values set for option Signed-By regarding source
Filed under Administration, Security
Learn to resolve the “Conflicting values set for option Signed-By regarding source” error in Linux.
The –switched-root and –deserialize Features of systemd
Filed under Administration, Processes
Learn what the –switched-root and –deserialize features are and how systemd uses them in Linux.
The Size Dynamics of tmpfs
Filed under Filesystems
Learn about the temporary file system (tmpfs) in Linux, and how its size and utilization are calculated by the kernel.
How Does NAT Reflection (NAT Loopback) Work
Filed under Networking
Learn why NAT reflection is useful and how to configure it with iptables on Linux.
How to Resolve NetBIOS Names From Linux
Filed under Networking
Learn how to resolve NetBIOS names on Linux to ensure smooth communication between Windows and Linux systems.
Dump HTTP Requests With Apache
Filed under Networking, Web
Learn how to dump Apache HTTP requests and inspect network logs on Linux.
Whatâs the Use of /etc/networks File in Linux?
Filed under Networking
Learn about the purpose of the /etc/networks file on Linux and how it impacts networking on a system.
Set up systemd Services With Session DBus on Headless Linux
Filed under Administration, Processes
Learn various methods of configuring systemd services with session DBus on a headless Linux system.
Listing All FTP Users in Linux
Filed under Administration
Learn how to list all FTP users, including system and virtual, on Linux.
How to Delay a systemd Script From Running at Boot
Filed under Administration, Processes
Learn how to configure various types of systemd services to delay their running during a Linux system boot.
Resolving the âPartition Does Not Start on Physical Sector Boundaryâ Warning in Linux
Filed under Filesystems
Learn how to resolve the filesystem warning “Partition does not start on physical sector boundary” in Linux.
How to Disable LVM Caching on a Specific Partition
Filed under Administration, Filesystems
Learn how to disable the LVM caching for a specific storage partition in Linux.
Displaying Full GPU Details With nvidia-smi
Filed under Administration
Learn how to use the nvidia-smi command in Linux to display full details about the installed GPU.
The Linux Kernel System Call Implementation
Filed under Processes
Learn how system calls bridge the space between user space and the kernel in Linux.
How Does systemd Use /etc/init.d Scripts
Filed under Administration
Learn how systemd converts init.d scripts for compatibility and executes them.
Practical Effects of Setting âUsePAM yesâ on SSH in Linux
Filed under Security
Learn how using PAM authentication affects SSH sessions and security on Linux.
Regenerate 70-persistent-net.rules in Linux Without Reboot
Filed under Networking
Learn how to regenerate the 70-persistent-net.rules file without rebooting in Linux.
Fixing Bad Geometry in ext4 Filesystems
Filed under Filesystems
Learn the causes of bad geometry on the ext4 filesystem and how to fix the error.
“active” vs. “clean” in mdadm: Key RAID States
Filed under Administration, Filesystems
Learn about the differences between “active” and “clean” RAID states in mdadm.
FIN_WAIT_2 State: Kernel’s Role in TCP Closure
Filed under Networking
Learn about the FIN_WAIT_2 state and how the Linux kernel’s configuration can affect the closure of network connections.
Enabling User Namespaces in the Linux Kernel
Filed under Administration, Security
Learn how to temporarily or permanently enable user namespaces in the kernel on Linux.
File Access: Memory-Mapped vs. I/O System Call Performance
Filed under Filesystems
Learn about the performance differences between memory-mapped and system call file access methods on Linux.
How to Check Whether a Process Is a Daemon
Filed under Processes
Learn how to determine if a Linux process is a daemon by checking its various characteristics.
Putting BTRFS on LVM in Linux
Filed under Filesystems
Explore the pros and cons of formatting LVM-managed volumes with BTRFS. Learn how to do so.
Linux Capabilities: Setting and Modifying Permissions
Filed under Security
Learn how to set and modify the capability permissions for Linux files and containers.
How to Track Newly Created Processes in Linux
Filed under Administration, Processes
A quick and practical guide to tracking newly-created processes in Linux.
Comparing nginx’s core, full, extras, and light Packages
Filed under Installation, Web
Learn how to choose the right nginx package for your Ubuntu server installation.
gcc Default include Directories in Linux
Filed under Building
Learn how gcc determines its default include directories and how to find them.
Linux Equivalent to C:\Program Files in Windows
Filed under Filesystems, Installation
Learn how Linux treats installation paths when comparing to Windows’ C:\Program Files directory.
Kernel Parameters acpi_osi=linux and acpi_backlight=vendor
Filed under Administration
Learn about the differences between the acpi_osi=linux and acpi_backlight=vendor kernel parameters, and how to apply them.
Analyzing Cache Misses Using the perf Tool in Linux
Filed under Administration
Learn how to analyze cache misses using the perf tool in Linux.
Checking for NUMA Capabilities
Filed under Administration
Learn how to determine whether a Linux system has NUMA capabilities.
Finding Out Which Linux Capabilities a Process Needs to Work
Filed under Processes
Learn how to check which capabilities are required by a process in order to function on a Linux system.
Meaning of âwatchdog did not stop!â Message at Shutdown in Linux
Filed under Administration
Learn about the “watchdog did not stop!” message on Linux, what it means, and how to disable it.
How Does Linux Know Where rootfs Is?
Filed under Administration, Filesystems
Learn how a Linux OS knows where the root filesystem is during the boot process.
Alternatives to the sed Command in Linux
Filed under Scripting
Learn about different Linux commands and Bash functions that can be used as alternatives to sed.
What Are the /dev/pts Files Used for?
Filed under Files
Learn how /dev/pts files are used on a Linux system and how the kernel interacts with them.
Understanding Timekeeping and Clocks in Linux
Filed under Administration
Learn about timekeeping and clocks on Linux and the differences between their various types.
What Is the Difference Between i686 and x86_64 Packages
Filed under Administration
Learn about the differences between i686 and x86_64 packages, and the scenarios where each can be used on Linux.
Benefits of Building the Linux Kernel
Filed under Building
Learn about the benefits of building the Linux kernel from scratch versus using a distributed and pre-compiled version.
Need for the irqbalance Command in Linux on Modern Hardware
Filed under Administration
Learn about the situations where the irqbalance command is useful on modern Linux hardware.
Difference Between Arch and Gentoo Linux Distributions
Filed under Administration
Learn about the similarities and differences between the Arch and Gentoo Linux distributions.
Difference Between OUTPUT and FORWARD Chains in iptables
Filed under Networking, Security
Learn about the similarities and differences in how the OUTPUT and FORWARD chains work in iptables.
DNF Package Manager: dnf history rollback vs. undo
Filed under Administration
Learn about the differences between history rollback and undo with the DNF package manager on Linux.
The Difference Between systemd Scope and systemd Slice
Filed under Administration
Learn about systemd Scope vs. Slice, and how both unit types are used to manage system services in Linux.
Kernel Counterparts of Pipes, FIFOs and Unix Domain Sockets
Filed under Building
Learn about various counterparts of the Linux kernel, including pipes, FIFOs and unix somain sockets.
Differences and Use Cases for Chrony and systemd-timesyncd
Filed under Administration
Learn about the differences between time-keeping systems Chrony and systemd-timesyncd, and their various use cases on Linux.
Why Is It Not Recommended to Put the Boot Partition on LVM
Filed under Filesystems
Learn about boot partition recommendations for Linux and why LVM isn’t a suitable host for it.
How Many Partitions Are Supported in Linux?
Filed under Filesystems
Learn about the limitations of hard drive partitions in Linux, including the maximum number of supported partitions.
What’s the Difference Between Kernel Drivers and Kernel Modules?
Filed under Building
Learn the difference between kernel modules and kernel drivers and how both are essential to a Linux system.
Implementation of Message Queues in the Linux Kernel
Filed under Building
Learn how message queues are implemented and used in the Linux kernel.
Security of NFS Over Internet in Linux
Filed under Networking, Security
Learn how to tighten NFS security for Internet connections.
Capabilities of Privileged Containers in Linux
Learn about the differences between normal and privileged containers in Linux.
What Is glibc?
Filed under Building
Learn about the GNU C Library (glibc) and why this component is important for programming and using Linux software.
Memory Usage per User in Linux
Filed under Processes
Learn how to sort memory usage statistics by user on Linux.
Creating Network Interfaces and Checking Interface Types
Filed under Networking
Learn how to create different types of network interfaces in Linux, and check what type any interface is.
What Is DBus Practically Useful For?
Filed under Processes
DBus allows different processes to interoperate in Linux, regardless of language. We look at how it works and how it allows parts of the Linux GUI to communicate.
Check Whether a Network Interface Is Physical or Virtual
Filed under Networking
Learn how to determine if a network interface is physical or virtual in Linux.
How to Check for User Group Privileges
Filed under Administration
Learn about the basics of user groups, why they are important, and different ways to check for user group privileges using command-line tools and system utilities.
How to Retrieve Password Expiry Time in Shell
Filed under Administration, Security
Learn how to check and retrieve the password expiration time of one or more users via the Linux shell.
Baeldung on Ops
- All
- Kubernetes (6)
- Scripting (1)
- Networking (1)
- Logging (1)
- Git (1)
- Docker (1)
- Deployment Tools (1)
Helm Flow Control
Filed under Kubernetes
Learn how to control the flow of Helm charts through examples.
Best Practices for Using Helm Charts
Filed under Kubernetes
Learn about best practices, tips, and tricks for using Helm with Kubernetes.
Pod-to-Pod Communication in Kubernetes
Filed under Kubernetes, Networking
Learn how pod-to-pod communication works in Kubernetes by seeing an example and various network configuration options.
Where Are the Kubernetes kubelet Logs Located?
Filed under Kubernetes, Logging
Learn about accessing kubelet logs in various locations for Kubernetes.
Auto-Update Docker Containers for Latest Base Images
Learn about various methods used to auto-update Docker containers for the latest base images.
What Is Pod Disruption Budget in Kubernetes
Filed under Kubernetes
Learn what pod disruption budgets are used for in Kubernetes and how to get started working with them.
Istio VirtualService vs. Kubernetes Service
Filed under Deployment Tools, Kubernetes
Learn about the differences between an Istio VirtualService and a Kubernetes Service, and how to use them.
Clone All Remote Branches in Git
Filed under Git
Learn about the methods and considerations for using Git to clone all remote branches of a repository.