During my working period, my backup script is using rsync to copy files to remote server, and I have just realized that without some special parameter, rsync does not handle well on sparse files. (a.k.a Files with holes in them that are holding a file system and just take the space needed by their actual size). A consequence is that on the target side, sparse files will take their real size on the new file system.

This article will guide you on creating a client-2-server OpenVPN instance. Our goal is to redirect all client traffic to VPN server. That means VPN server would serve as a gateway for local traffic. It's useful to bypass some STUPID National firewalls,or to test IP-restricted applications.

The most important part for this installation is openvpn's two config files, one is the server side configuration, and the other is for client side.

This is a server side configuration file:
$ cat /usr/local/openvpn/etc/server.conf

Is it possible for someone to create a malicious filter without having access to your Gmail username and password? No, however, they
can force you to create the filter without your knowledge.

The blogosphere is buzzing about a Gmail Security Flaw that has caused some people to lose their domain names registered through GoDaddy.

When you need to compare two txt files, you might be about to try following ways,
1, Create a simple perl or python or php script by yourself.
2, Using google to find out some already existed scripts to do comparation for you.
3, Download some windows softwares to help compare the text files.

"This document provides an introduction to NFS as implemented in the Linux kernel. It links to developers' sites, mailing list archives, and relevant RFCs, and provides guidance for quickly configuring and getting started with NFS on Linux. A Frequently Asked Questions section is also included. This document assumes the reader is already familiar with generic NFS terminology. "

AMD AND REDHAT have just done the so called impossible, and demonstrated VM live migration across CPU architectures. Not only that, they have demonstrated it across CPU vendors, potentially commoditising server processors. Eeek!

The concept is simple, click a button, and your VM moves from one machine to the next. The execution for similar architectures has been done for ages, AMD can do it from E-Step Opterons to a promise of Magny Cours. Intel is a little more restrictive, but they can do it between iCore iNumber iNumberals as iwell.

This is a benchmark report from GraphicsMagick's offical website. I record it here just for a quick refer, I may need it in the following days. As it's from GraphicsMagick itself, simply dont trust the results, just pay more attention on how they performed their benchmark.

These three are all in-memory file-system. Sysfs was originally based on ramfs. ramfs was written around the  Linux 2.4 time. It's an exercise in elegance, as it showed just how easy it was to write simple filesystem using the VFS layer. Because of its simplicity and use of the VFS, it provided a good base from which to derive other in-memory based filesystems.