As system administrators, we’d better know SystemTap and be able to assemble its existed recipes for comprehensive system analysis. When I am on my way to make a collection of  systemtap scripts, I realize that I should give a brief introduction to this powerful design first, although it has been [...]

Note that this is a forwarded version from serverfault.com, and the original post is here.  Xen is an hypervisor that runs on metal (the pc / server) and then hosts virtual machines called domains.

You may have heard of Netperf, which is a benchmark tool that is used to measure the performance of many different types of networking.  But normally what we care are the throughput and latency. As the throughput may affected by different factors like the package size, you may have to run many tests [...]

As from OpenSSH-4.4, we can add command-line args for the sftp-server subsystem configuration. When combined with these arguments, it allows us to log what is performing during an SFTP session. Be aware that there is a bug in enabling the logging feature if you use it with ForceCommand, and affects versions prior [...]

As long as you are all right with a little downtime of the EC2 instance (in a few minutes), it is possible to extend the root partition on a running EBS boot EC2 instance, without needing to start a new instance.

From the topic above, you may have remembered one of our former post “what data is cached by operation system“. This is a similar tool as Fincore, but it’s more powerful. It’s written in C and supports UNIX and unix-like systems.

When using Amazon S3 to store the web files, you may face this question sometimes, How can I keep the files for my productive environment exactly the same as develop environment? (In other words, you want to remove the unused files in dev environment.)

If you use Amazon S3 (or CloudFront) as a web hosting provider, here are some essential tips that you should know about. These tips are mainly for front-end optimizations, including reduce S3 bandwidth, reduce unnecessary requests to S3, check abnormal requests and optimizations on file transfer.

When you have a running EC2 instance, you can build your production environment there, install whatever the packages you need, tweak system-wide configurations to meet your needs… Then you might wanna build your own AMI image to simplify future deployment.

In one of our former post, we have a way to check what type of data is cached by our operating system. Is there a way for us to release memory from Linux like what we can do in Windows?