The 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…
Sharing the networking is important and setting up a gateway is a good solution to it. Building up the gateway on a Linux box is easy, cost efficient and reliable. With a Linux box, you can share the internet connection or the only cable connected to the network. The Linux box network configuration The Linux…
For most of cases, you should not disable SELinux. However, for some users, SELinux may cause problems or is not needed. We may just make it not block operations or totally disable it. Making SELinux log warnings instead of blocking For many cases, people find SELinux blocks operations. For tests or some other situations, you…
We can set up a socks proxy on top of a SSH tunnel. Besides the common proxy functions, such as web browsing, the proxy on top of SSH tunnel also ensures the security between the browser and the proxy server (the SSH server). In this post, we introduce and explain how to set up a…
Sometimes we need to have the GUI of some application on the remote server. ssh’s X11 forwarding with “-X” parameter is a good and fast method. But if we want to have a whole desktop environment, vnc is a good choice. In this post, the method of how to control remote server using vnc through…
We may need to flush DNS cache of our client when the site’s DNS has been changed. Flush DNS cache of Linux with NetworkManager/dnsmasq You may simply restart NetworkManager by sudo systemctl restart NetworkManager Flush DNS Cache on (Old) Linux with nscd 1) Use su – to get root privilege or sudo with the following…
Assumption: There are VBD based Xen DomU virtual machines stored under /home/xen/vm-f11-sample/. There are two files under vm-f11-sample: vm0-f11.run (The configuration file) and vmdisk0 (The virtual disk). Now we want to duplicate the virtual machine vm0 stored under vm-f11-sample to vm-10.0.0.213 which is stored under vm-10.0.0.213. And vm-10.0.0.213’s ip will be 10.0.0.213. The steps to…
Git and SSH are both powerful tools, and git/ssh work well together. We introduce how to set up git server via ssh in this post. Git server through SSH is easy and fast to set up, although every user will have access to all repositories in the git server over SSH and every user is…
DVD disks are still commonly used in some areas while the disks are not fast and convenient enough for frequent usage. For frequent usage or archiving, an image of the DVD on hard drives will be better. ISO images do not use a particular container format. They are just a sector-by-sector copy of the data…
How to speed Up Firefox DNS Lookup in Linux: 1. Close IPV6 support # echo “alias net-pf-10 off” >> /etc/modprobe.conf # echo “alias ipv6 off” >> /etc/modprobe.conf Type “about:config” into the address line and enter. Set “network.dns.disableIPv6” to “true” 2. Some other tweaks Type “about:config” into the address line and enter. Set “network.http.pipelining” to “true”…
How to configure NetworkManager to connect to sMobileNet in HKUST is introduced in this post. The wireless network connection configuration for sMobileNet in NetworkManager The SSID is “sMobileNet” Wireless security is “WPA & WPA2 Enterprise” Authentication is “Protected EAP (PEAP)” Anonymous identity is “” (empty) CA certificate is “(None)” (there will be a warning appear,…
As a multimedia enthusiast, you may want to convert your movie files to audio files for various reasons such as creating soundtracks, audio books or listening to dialogues & music without the video. Converting movie files to WAV and MP3 files using MPlayer and LAME is a simple and straightforward process. By following the steps…
Linux has many tools for mounting, creating and burning iso image files. In this posts, I will introduce how to use the iso files on Linux. The tools we used in this post are mount, genisoimage and wodim. 1. Mount an iso image file Mounting an iso on Linux is straightforward. We mount the iso…
We may want to run some jobs for every two weeks/months/days… under some situation such as backing up for every other week. In addition, we may add more complex rules for running jobs, e.g. run a command when the load of the server is higher than a certain level. With the help of the shell…
Compress/uncompress files are frequent operations. The normal tools for compressing/uncompressing in Linux is gzip, bzip2, 7z, rar and zip. This post introduces how to compress and uncompress file in Linux using these tools. We use best compressing rate with all these tools and mark the options for “best rate” in bold fonts. We can delete…
TeraSort is one of Hadoop’s widely used benchmarks. Hadoop’s distribution contains both the input generator and sorting implementations: the TeraGen generates the input and TeraSort conducts the sorting. Here, we provide a short tutorial for using the Hadoop TeraSort benchmark. TeraGen generates random data that can be used as input data for a subsequent running…
Update: If you are new to Hadoop and trying to install one. Please check the newer version: Hadoop Installation Tutorial (Hadoop 2.x). Hadoop mainly consists of two parts: Hadoop MapReduce and HDFS. Hadoop MapReduce is a programming model and software framework for writing applications, which is an open-source variant of MapReduce that is initially designed…
How to manage users and repositories and how to use these repositories will be introduced in this post. Please refer to Setting Up a Git Server Using Gitosis for how to set up the git server. Please refer to Howto for New Git Users for how to use git as a new user. Create a…
Update: Since gitosis is not maintained and supported, please check out gitolite for setting up a new git server. (see the comment from Sitaram Chamarty, the gitolite author, the author of gitolite.) Gitosis is a piece of software writen by Tommi Virtanen for hosting git repositories. It manages multiple repositories under the same user account….
Hadoop is designed to run on [[hadoop-installation-tutorial|hundreds to thousands of computers]] inside cluster. However, Hadoop is configured to run things in a non-distributed mode as a single Java process by default. This is specially useful for debugging since distributed debugging is really a nightmare. This post introduces how to set up a standalone Hadoop environment….