Update on Oct. 9, 2014: You should be aware of the possible security problems of blowfish and it is suggested not to be used. Instead, you may consider ChaCha20 as suggested by Tony Arcieri. To use this with OpenSSH, you need to specify the Ciphers in your .ssh/config files as chacha20-poly1305@openssh.com possibly with another default…
I ever introduced seting up git server using SSH or gitosis. However, gitolite is the way to go for managing git servers if you want an lightweight authentication layer. gitolite provides many very usefull features which can control each user’s right on each branch. I set up one gitolite git server and am very happy…
The public cloud storage services like Amazon S3, Google Cloud Storage and Windows Azure Storage replicate the data to ensure high availability. On the other hand, with data being replicated, the storage services exhibits certain data consistency models. Different cloud service providers employ different data consistency models nowadays. In this post, we survey the data…
Port forwarding (or tunnelling) is a method to forward one network traffic to another. We will introduce how to forward ports using SSH tunnel in this post. A simple example Let’s start with a simple and useful example: we want to forward local port 8080 to server:port. We can easily do this by using ssh…
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…
John Ousterhout is a professor of Deparment of Computer Science from Stanford University. One recent project he is working on is the RAMCloud, a “new class of storage, based entirely in DRAM, that is 2-3 orders of magnitude faster than existing storage systems”. He posts his “Favorite Sayings” on his homepage. These sayings are precious…
OCaml is an interesting functional language. There are lots learning materials on the Internet. I compile a list of resources for OCaml learning and reference. Recommended OCaml learning and reference material Online book of Real World OCaml by Yaron Minsky, Anil Madhavapeddy, Jason Hickey. A very good tutorial by Jason Hickey: http://www.cs.caltech.edu/courses/cs134/cs134b/book.pdf. The OCaml system…
I want to move the sub domain blog.pkill.info to systutorials.com permanently. I can manage all the pages I want to post using WordPress. Changing domain in a bad way is dangerous. Put a page the tell the reader that the site is moved to a new domain is very unfriendly to the user and also…
This post compiles a list of tutorials on the Internet for Linux beginners. Linux beginners usually get headache from the “seemed” complexity of the Linux operation system. But once they get into the gate and get familiar with Linux, they will love it. UNIX Tutorial for Beginners “A beginners guide to the Unix and Linux…
MPlayer is a universal (nearly) movie/music player on Linux and many more systems. It’s also my favourite player and MPlayer plays movie or music files in any format that I drop to it. Now, let’s take a look at how to use MPlayer play DVD. MPlayer plays “DVD” in many formats: DVD disks, ISO files,…
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…
When I get my new Compaq Presario CQ35-240TX, of course, the first thing is to install Fedora ;) But unfortunately, after installation there is no sound! It seems there is something wrong with the driver configuration. Here is a solution to this: Add these two line at the end of /etc/modprobe.d/dist.conf options snd-hda-intel model=hp-m4 enable=1…