If you’re seeing PHP errors like Class ‘DOMDocument’ not found, your PHP installation is missing the XML extension. This is common after migrating sites or fresh installations where the base PHP package doesn’t include DOM support out of the box. Install php-xml The solution is straightforward — install the php-xml package: sudo dnf install php-xml…
The default data directory for MySQL and MariaDB installed from official repositories on modern distributions is: /var/lib/mysql This applies to CentOS 7, Rocky Linux 9, Fedora, and most RHEL-based systems. Finding the Data Directory Programmatically If you’ve customized your installation or need to verify the exact location, there are several reliable methods. Query MariaDB/MySQL Configuration…
If you’re running an older CentOS or RHEL system with Vim 7.4, upgrading to Vim 8 or later gives you modern features like async I/O, jobs API, terminal emulator support, and better plugin performance. Here are the practical approaches. Check Your Current Version $ vim –version VIM – Vi IMproved 7.4 (2013 Aug 10, compiled…
To load a kernel module automatically at system startup, create a configuration file in /etc/modules-load.d/ with a .conf extension. The systemd-modules-load.service daemon reads these files during early boot and loads the specified modules. Basic method Create a new configuration file. For the ixgbe driver example: echo “ixgbe” | sudo tee /etc/modules-load.d/ixgbe.conf Or use your editor…
When launching WPS Office on Rocky Linux 9+ or similar distributions, you may encounter this error: $ wpp /opt/kingsoft/wps-office/office6/wpp: error while loading shared libraries: libbz2.so.1.0: cannot open shared object file: No such file or directory This is a library version mismatch issue common when WPS Office binaries were compiled against an older version of libbz2….
The command journalctl -b -1 should show the previous boot’s journal, but on many systems it returns: Failed to look up boot -1: No such boot ID in journal This happens because persistent journal storage isn’t enabled by default. Without it, journald only keeps logs in volatile memory (/run/log/journal), which gets cleared on shutdown. Enable…
EncFS provides an encrypted filesystem in user space — files are encrypted on the fly and stored in an existing directory. It’s lighter than LUKS and doesn’t require root access or dedicated partitions. Here’s how to set it up on CentOS 6. Install EncFS EncFS is available from the EPEL repository: # Enable EPEL sudo…
The default TeX Live packages available through standard repositories are often outdated and incomplete. The official TeX Live installer provides access to current versions and the full package collection, though it requires around 4-5GB of disk space. Prerequisites Before starting, ensure you have the required dependencies installed: sudo yum groupinstall -y “Development Tools” sudo yum…
When trying to mount an encrypted EncFS directory as a normal user, you may encounter this error: $ encfs -s ~/t/.enc ~/t/enc EncFS Password: fuse: failed to exec fusermount: Permission denied fuse failed. Common problems: – fuse kernel module not installed (modprobe fuse) – invalid options — see usage message Even though the same command…
Dia is a GTK+ based diagram creation program for Linux. It supports flowcharts, network diagrams, circuit diagrams, UML diagrams, and many other types. Here’s how to install and get started with Dia on CentOS 7. Install Dia from EPEL Dia is available in the EPEL (Extra Packages for Enterprise Linux) repository: # Enable EPEL if…
The bottom panel in GNOME Classic displays the window list via the “Window List” extension. If you don’t use it, there are several ways to remove it depending on your approach. Method 1: Context menu removal (Recommended) The simplest approach if your GNOME version supports it: Hover over a blank area of the bottom panel…
HP printers and scanners on Rocky Linux, CentOS, or RHEL require the HPLIP (HP Linux Imaging and Printing) package. This guide covers the complete setup process. Install HPLIP packages Start by installing the core HPLIP packages: sudo dnf install hplip hplip-gui hpijs On older CentOS 7 systems, use yum instead of dnf. HPLIP may prompt…
aria2 is a lightweight, multi-protocol download manager that supports HTTP(S), FTP, BitTorrent, and Metalink protocols. It’s particularly useful for resumable downloads, parallel connections, and command-line automation. Prerequisites You’ll need root or sudo access. This guide covers CentOS 7, CentOS Stream, and Rocky Linux 8+. For older systems still on CentOS 7, package availability may be…
curlftpfs is a FUSE-based filesystem that lets you mount FTP/SFTP servers as local directories. This is useful for treating remote FTP locations like local storage without downloading files individually. Prerequisites FUSE kernel module loaded (usually default on modern systems) Root or sudo access Network connectivity to your FTP server Installation on RHEL/CentOS/Rocky Linux The curlftpfs…
When you create VMs in KVM, they’re typically assigned IP addresses via DHCP. Finding those addresses so you can SSH in requires a few steps. Here are the practical approaches. Using virsh domiflist and ARP The traditional method combines virsh domiflist to get the VM’s MAC address, then looks it up in the ARP table:…
VNC (Virtual Network Computing) provides a graphical remote desktop connection to Linux servers. It’s straightforward to set up and useful when you need GUI access to a headless or distant system. Installation On the server side, install a VNC server package. TigerVNC is the most reliable choice across distributions: Debian/Ubuntu: sudo apt install tigervnc-server tigervnc-common…
SSHFS (SSH Filesystem) mounts a remote filesystem over SSH, letting you interact with remote files as if they were local. It uses SFTP under the hood, so no additional server configuration is needed beyond SSH access. Install SSHFS on CentOS 7 # Enable EPEL repository sudo yum install epel-release # Install sshfs sudo yum install…
CONFIG_HZ sets the kernel’s internal timer interrupt frequency (measured in Hz). This determines how often the kernel’s scheduler runs and how fine-grained process preemption can be. The default value is typically 250 Hz on most distributions, though some set it to 1000 Hz for lower latency workloads. Higher CONFIG_HZ values (like 1000 Hz) reduce scheduling…
Adobe Flash Player reached End of Life on December 31, 2020, and Adobe blocked all Flash content from executing in 2021. Installing Flash Player on CentOS 7 in 2026 is neither practical nor recommended—the plugin won’t execute Flash content anyway, and doing so introduces security vulnerabilities to your system. If you’re still running CentOS 7,…
[md] The RTL8192cu is a legacy USB WiFi adapter that’s still in use, but it has known stability issues on modern kernels. If your adapter keeps dropping connections or fails to resume after sleep, you’re likely hitting the same power management bug that affects many devices. ## Disable Power Management The most reliable workaround is…