The performance of Xen’s Dom0 is important for the overall system. The disk and network drivers are running on Dom0. I/O intensive guests’ workloads may consume lots Dom0′s CPU cycles. The Linux kernel calculates various network related parameters based on the amount of memory at boot time. The kernel also allocate memory for storing memory…
In this post, how to unified Linux login and home directory using OpenLDAP and NFS/automount will be introduced. 0. System environment This solution is tested on Fedora 12 systems and CentOS 5. LDAP and NFS server: IP: 10.0.0.2 OS: Fedora 12 x86_64 ldap base dn: “dc=lgcpu1″ Clients: IP: 10.0.0.1/24 OS: Fedora 12 x86_64 1. LDAP…
UDP has its advantages over TCP, such as being relatively lightweight and receiving one packet per read call (recvmsg), although the programmers need to handle related issues, such as packet lost and out-of-order packets delivery. This post gives information and references on how to write UDP programs in a C/Linux environment. What is UDP Check…
It is quite common to measure the time in programs using APIs like clock() and gettimeofday(). We may also want to measure the time “accurately” for certain purposes, such as measuring a small piece of code’s execution time for performance analysis, or measuring the time in time-sensitive game software. It is hard to measure the…
If /etc/fstab file is created with errors or the hardware configuration changes such as adding hard disks, Linux will boot into failure state. We can bypass the fstab failure by adding booting parameters to Linux. We can do this in two methods: Method 1: Boot to single user mode When booting into single user mode,…
In Linux, we use passwd to change password, but passwd requires input from stdin to get the new password. It is common case that we may want to change the password non-interactively, such as creating new user accounts and change or set password for these accounts on a number of Linux boxes when the new…
For UNIX users/developers, having the power of the user 0 (root’s UID) on our hands is essential. It also allows us to have complete control over the system. And one more thing we all have in common is that we hate Windows. Thus, we set out in search of an operating system for our own…
The socks proxy I created following Proxy Using SSH Tunnel works very well on both Linux and Windows. However, when I try to configure my iPhone and iPad with iOS, I find iOS does not support socks proxy in its settings interface. I don’t know why it is not added while socks proxy is indeed…
xclip is a tool to copy the copy the output of commands from a command line in a terminal to X selection or clipboard. It connects the command line interface and the X selections (clipboard) and is a very useful tool. For example, processing some text in vim in a terminal and then copying it…
Here is a list of tutorials for learning how to write MapReduce programs on Hadoop, the opensource MapReduce implementation with HDFS. MapReduce Tutorials The official tutorial on Hadoop MapReduce framework: http://hadoop.apache.org/docs/r1.0.4/mapred_tutorial.html. Yahoo! Hadoop Tutorial A comprehensive tutorial on Hadoop from Yahoo! Developer Network: http://developer.yahoo.com/hadoop/tutorial/. More about MapReduce To better understand the design behind MapReduce, it…
MediaWiki set’s the default page (the homepage) to the “Main Page” by default. The name “Main Page” is too general and does not give more meanings. Usually for a specific site, we may change it to some meaningful name and URL. This is a configurable in MediaWiki. This tutorial introduces how to change MediaWiki’s Main…
MediaWiki’s Sidebar can be configured as a special page. This page’s title is “MediaWiki:Sidebar”. For example, if a MediaWiki site www.example.com is configured to use [[search-engine-friendly-url-for-mediawiki]], the URL for edit the Sidebar is: http://www.example.com/w/MediaWiki:Sidebar It may look like this: * navigation ** mainpage|mainpage-description ** recentchanges-url|recentchanges ** randompage-url|randompage ** currentevents-url|currentevents ** portal-url|portal ** helppage|help * SEARCH…
This article is an instruction of how to use https://www.systutorials.com/proxy-using-ssh-tunnel/ on a Windows machine. The mechanism is similar as the one in https://www.systutorials.com/proxy-using-ssh-tunnel/ with “Proxy listening to localhost port only”. Download PuTTY PuTTY is the software we use here for port forwarding. Please download it following the links in https://www.systutorials.com/open-source-and-portable-ssh-scp-sftp-and-vnc-clients-for-windows-to-remote-control-linux/. Configure PuTTY and create a…
More and more users are browsing the Internet using a mobile device. It is preferred to provide good experience for these users. One method to service a mobile version of the page to a user with a mobile device. This tutorial introduces how to add mobile skin support for MediaWiki. Skin for mobile devices I…
MediaWiki is the wiki-engine that runs Wikipedia. In this tutorial, we introduce how to configure search engine friendly URLs in MediaWiki. ==Search Engine Friendly URLs== Default MediaWiki URLs look like www.example.com/w/index.php?title=TITLE which is a little ugly. To make it more search engine friendly, we will change it to SEO-friendly URLs like www.example.com/w/TITLE. ==Enabling Search Engine…
Google Drive is nice cloud storage which provide document editing features. However, it does not yet provide a Linux client. I find a good third party tool that works with Google Drive on Linux very well: google-drive-ocamlfuse. The website of google-drive-ocamlfuse provides easy to follow instructions to install it. In this tutorial, we show a…
Automatic keyboard pressers are useful tools. However, it seems that there is no simple and easy to use automatic keyboard presser for Linux if you search for “automatic keyboard presser linux”. After some digging, I find using the xvkbd with some options is a good method for automatic keyboard pressing though it is not designed…
noip2 is a dynamic update client for No-IP to keep your current IP address synchronized with your No-IP domain, no matter whether the IP is dynamically requested via DHCP or static assigned. Furthermore, with the domain name, we can host site using a “static” domain whose CNAME points to the No-IP domain. noip2 is a…
GNOME 3.8 introduces the classic mode: Classic mode is a new feature for those people who prefer a more traditional desktop experience. Built entirely from GNOME 3 technologies, it adds a number of features such as an application menu, a places menu and a window switcher along the bottom of the screen. Each of these…
C++ References Reference of the C++ Language Library, with detailed descriptions of its elements and examples on how to use its functions: http://www.cplusplus.com/reference/ C++ reference: http://www.cppreference.com/w/ C++ Styles I compile a list of C++ styles on the Internet. http://geosoft.no/development/cppstyle.html http://google-styleguide.googlecode.com/svn/trunk/cppguide.xml http://www.mactech.com/articles/develop/issue_02/C%2B%2B_Style_Guide_v007.html http://www.cs.uga.edu/~dkl/1302/Fall99/style.html