LVM Fundamentals LVM (Logical Volume Management) abstracts physical storage into logical volumes, giving you flexibility to resize filesystems, snapshot data, and manage disk space without downtime. It sits between your physical disks and the filesystems you mount. The three core LVM concepts are: Physical Volumes (PVs): Physical disks or disk partitions Volume Groups (VGs): Collections…
Evolution Data and Configuration Locations on Linux Evolution is a full-featured personal information management suite that handles email, contacts, calendars, and tasks. It includes enterprise features like native Microsoft Exchange support and integrates deeply with GNOME’s ecosystem. To troubleshoot issues, migrate data, back up configurations, or secure your setup, you need to know where Evolution…
NFSv4 Port Forwarding and External Network Access NFSv4 significantly simplifies network exposure compared to NFSv3. Where NFSv3 requires managing multiple dynamic ports (mountd, statd, lockd), NFSv4 uses only port 111 (rpcbind) and port 2049 (NFS). This makes firewall configuration and port forwarding straightforward. For production environments, consider implementing Kerberos authentication (krb5, krb5i, or krb5p) instead…
Historical Reference: This post covers GNOME 2 / early KDE desktop customization. Modern GNOME (40+) and KDE Plasma (5/6) have different configuration approaches. See Arch Wiki for current setup guides. Gnome Shell has a clean design. But many users want to get more from the desktop environment. Gnome 3’s extension system can help users customize…
Note: This post covers Linux fundamentals. Core concepts remain valid, but some commands and package names may differ on modern distributions. See your distro’s documentation for current details. People are sometimes given access to Linux/Unix and asked to change their initial passwords. But for beginners, changing a Linux/Unix password is not an easy task, especially…
Note: This post covers Linux fundamentals. Core concepts remain valid, but some commands and package names may differ on modern distributions. See your distro’s documentation for current details. Linux may report “device is busy” when we try to umount a filesystem. This behavior is reasonable as it can help us avoid data loss by disallowing…
Note: This post covers Linux fundamentals. Core concepts remain valid, but some commands and package names may differ on modern distributions. See your distro’s documentation for current details. Bash script may need to get its own path. In normal Bash script, $0 is the path to the script. However, when a script is sourced, such…
Note: This post covers Linux fundamentals. Core concepts remain valid, but some commands and package names may differ on modern distributions. See your distro’s documentation for current details. It is common to execute commands on many nodes/hosts via SSH for managing a cluster of Linux servers. On Linux, there are many choices for this task….
Note: This post covers Linux fundamentals. Core concepts remain valid, but some commands and package names may differ on modern distributions. See your distro’s documentation for current details. Linux is a great platform for software development targeting servers or backends. In general, working on Linux is very productive. The problem that beginners on Linux face…
Note: This post covers Linux fundamentals. Core concepts remain valid, but some commands and package names may differ on modern distributions. See your distro’s documentation for current details. Doing actions upon changes of files and directories is very useful. Examples like compiling a project after the source code files are changed, sending emails after important…
Note: This post covers Linux fundamentals. Core concepts remain valid, but some commands and package names may differ on modern distributions. See your distro’s documentation for current details. Grub2 config file may need to be re-generated after changing Grub2 configurations such as configuration changes and setting default boot entries. The Grub2’s config file may be…
Note: This post covers Linux fundamentals. Core concepts remain valid, but some commands and package names may differ on modern distributions. See your distro’s documentation for current details. Having to go the the server room to reset servers is the most headache thing for admins managing a cluster of Linux servers in a remote site….
Historical Reference: This post covers GNOME 2 / early KDE desktop customization. Modern GNOME (40+) and KDE Plasma (5/6) have different configuration approaches. See Arch Wiki for current setup guides. A pop-up terminal is great and handy on Linux and similar OS. On KDE, Yakuake is great. On Gnome or GTK, I ever tried Guake….
Note: This post covers Linux fundamentals. Core concepts remain valid, but some commands and package names may differ on modern distributions. See your distro’s documentation for current details. If your website uses a self-signed certificates, Chrome will show a warning every time and you need clicks to continue. In this post, I will introduce how…
Note: This post covers Linux fundamentals. Core concepts remain valid, but some commands and package names may differ on modern distributions. See your distro’s documentation for current details. The Linux kernel has a generic driver for a graphic framebuffer named vesafb on intel boxes. It provides a nice large console for most of modern displays….
Archived Content: This post covers Hadoop 1.x/2.x which is no longer maintained. Modern Hadoop 3.x+ includes significant improvements in YARN resource management, HDFS federation, and erasure coding. For new deployments, consider current Hadoop documentation or cloud-native alternatives like AWS EMR, Google Dataproc, or Azure HDInsight. Hadoop 2 or YARN is the new version of Hadoop….
Note: This post covers Git basics or gitolite/gitosis setup. Core Git commands remain valid. For modern Git workflow tools, see Git documentation or hosted solutions like GitHub, GitLab. It is common to set up git servers to host git repositories. Branching is lightweight in git and a very friendly mechanism to manage code. Here, I…
I use Emacs in terminals and start/close Emacs frequently as needed like in a file checking-editing-closing loop. However, Emacs seems take some time to start up especially some heavy modes are used. How to make Emacs start up faster? (If you just want the solution/script first, find the command in the summary section.) My solution…
Historical Reference: This post covers GNOME 2 / early KDE desktop customization. Modern GNOME (40+) and KDE Plasma (5/6) have different configuration approaches. See Arch Wiki for current setup guides. Gnome 3 is great and I can understand that it emphasizes on simplicity. However, the configuration settings for Gnome 3 does not provide tools for…
Note: This post covers Git basics or gitolite/gitosis setup. Core Git commands remain valid. For modern Git workflow tools, see Git documentation or hosted solutions like GitHub, GitLab. A method to send email notification to a list of email addresses by the remote git server after every push from the client will be introduced in…