MAC stands for Media Access Control which is a six byte number, usually expressed as a twelve digit hexadecimal number. IPs in LAN are translated to MAC address by the ARP (Address Resolution Protocol) protocol. For some reasons such as keeping the true MAC address from being logged, accessing to the network which bounds IPs
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Author: Eric Ma
Eric is a systems guy. Eric is interested in building high-performance and scalable distributed systems and related technologies. The views or opinions expressed here are solely Eric's own and do not necessarily represent those of any third parties.How to Set Date, Time and Timezone in Linux
Posted onHow to set date, time and timezone on Linux/Unix box will be introduced in this post. Unix time, or POSIX time which is a system for describing points in time is the number of seconds elapsed since midnight UTC on the morning of January 1, 1970, not counting leap seconds. The number of seconds elapsed
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Useful Mplayer/Mencoder Commands
Posted onmplayer/mencoder are powerful tools. This is a list of useful mplayer/mencoder commands. Extract the audio, convert it to PCM and write the resulting wave file to audio.wav: mplayer -vo null -hardframedrop -ao pcm:file=audio.wav video.avi Convert .wav file to .mp3 file: lame -h out.wav out.mp3 Preview a video composed of all jpeg files from the current
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Making dnf/yum Not Update Certain Packages
Posted onWe may not want to update some packages such the kernel on a stable server while updating the system. If we run “dnf update” or “yum update”, we may get suggested by dnf/yum to install all the packages with updates. In this post, how to make dnf/yum not update certain packages such the kernel when
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Linux Port Forwarding Using iptables
Posted onLinux port forwarding is simple to do with iptables which may probably already being used as the firewall or part of the setting up a Linux gateway. In the Linux kernel, port forwarding is achieved by packet filter rules in iptables. Port forwarding Port forwarding also called “port mapping” commonly refers to the network address
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A Simple Makefile for Latex
Posted onCompiling a latex documents may take several steps when bibtex is used with latex. However, this latex compilation process is the same for most documents. We can make it a template with Makefile so that simply running make will generate the dvi/ps/pdf files for us. A simple Makefile for using latex with bibtex enabled is
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How to Use Google Apps Account for GTalk in Pidgin
Posted onI believe many users are using pidgin and google apps. Google apps support Google Talk. Can we use it in Pidgin? The answer is yes. How to use Google apps account for Google Talk in Pidgin will be introduced in this post. Let’s use one email address as the example: eric @ example.com First add
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How to Set Up eCryptFS on Linux – The Manual Way
Posted onHow to set up eCryptFS in Linux will be introduced in this post. We can store encrypted files in one eCryptFS directory, the manual way. The content can be seen only after it is mounted as eCryptFS file system. Otherwise, the users can only see garbled characters in the files. Note that this tutorial will
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Setting Up a NFS Server on Top of tmpfs /dev/shm
Posted ontmpfs has blazing speed. Why not set up a high speed NFS server on top of tmpfs? A little trick is required for setting NFS server on top of /dev/shm. If we add a normal entry in /etc/export and them run # exportfs -a exportfs will give us a warning like this: exportfs: Warning: /dev/shm
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Speeding Up Firefox in Linux
Posted onFirefox can be much faster on Linux! Let’s speed up Firefox on Linux system. Part 1 and 2 only config firefox, so it can also be used on other platform such as Windows. 1. Pipe-lining network connection Most of us use a broad band width network, then why not pip line the connection from Firefox?
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How to Backup Linux Home Directories Using rsync
Posted onI need to backup my Linux home directory to one of my portable hard disk. I tried to use git, but failed since git doesn’t support large file (I failed after many tries, I have file larger than 5G). I find rsync, the fast, versatile, remote (and local) file-copying tool and I am happy with
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Query Installed Files from Package and Package for Installed File in Fedora
Posted onHow to query installed files from a package and query which package one installed file is in will be introduced. Query installed files from a package $ rpm -ql package_name Query which package a installed file is in $ rpm -qf /full/path/to/installed/file
Setting Up Xen Dom0 on Fedora : Xen 3.4.1 with Linux Kernel 2.6.29 on Fedora 12
Posted onPlease refer to for the latest stable Xen Dom0 solution. In this post, the detailed tutorial for setting up Xen 3.4.1 dom0 on top of Fedora 12 with kernel 2.6.29 will be introduced. Hardware: Dom0 hardware platform: Motherboard: INTEL S5500BC S5500 Quad Core Xeon Server Board CPU: 2 x Intel Quad Core Xeon E5520 2.26G
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Gnome2 Style: Shiki Colors+Gnome Colors
Posted onThe Linux Gnome style that I like is Shiki-color + Gnome colors icon theme. It looks pretty and professional and it is fast. How to install them: Gtk engine: # yum install gtk-murrine-engine Icon theme: # yum install gnome-colors-icon-theme Theme: Dowload from here: http://gnome-look.org/content/show.php/Shiki-Colors?content=86717 Install it by Appearance Preference -> Install. Configuration: Appearance Preference ->
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Mounting Remote Folder Through SSH
Posted onSSH is a very convenient tool on Linux that can be used to [[port-forwarding-using-ssh-tunnel]], [[proxy-using-ssh-tunnel]] and others besides its basic functions (remote shell). We can also use SSH to mount a remote folder to a local directory. We can use `sshfs` to mount remote folder through SSH tunnel securely over network. Install sshfs Install `sshfs`
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How to Set Up Password-less SSH Login on Linux
Posted onAutomatic passwrod-less ssh login can make our life easier. To enable this, we have 2 options: using key-based authentication by copying our SSH public keys to the remote machines for automatic password-less login or using password-based authentication. I will introduce the 2 options in the post. Before you start, please note that key-based authentication is
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How to Capture Desktop Video on Linux using ffmpeg
Posted onffmpeg is a powerful tool and it can do the work of capturing Linux desktop video very well. ffmpeg is a very fast video and audio converter that can also grab from a live audio/video source. ffmpeg can grab X11 input and create a video file such as mp4 at specific fps with the specific
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How to Install MPlayer and MEncoder on Fedora
Posted onFedora does not include MPlayer or MEncoder for some reasons in its official repositories. But RPMfusion does it for us. Let’s install mplayer and mencoder and learn some tricks to play rmvb files. 1. Add RPMfusion repository: Enable RPM Fusion repositories 2. Install MPlayer and MEncoder # dnf install mplayer mencoder 3. Get codecs Most
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Installing akmod NVIDIA Driver on Fedora
Posted onInstalling akmod NVIDIA driver from rpmfusion on Fedora 12. First make sure your nvidia card is in “Supported NVIDIA GPU Products List”: Click here for the list 1. Add rpmfusion repository: Enable RPM Fusion repositories 2. Install akmod nvidia driver akmod builds the required kmod on bootup # yum install akmod-nvidia xorg-x11-drv-nvidia-libs.i686 3. Add nouveau
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Sending Email Using mailx/s-nail in Linux Through Gmail SMTP
Posted onThe heirloom mailx (or s-nail if you are using Ubuntu 18 or later or similar releases) command in Linux is still providing service for guys like me, especially when we need to send email automatically by script. Gmail is great. Now, how to use gmail’s smtp in mailx/mail? gmail is a little special since gmail’s
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