xargs: Build and Execute Commands with Arguments from Standard Input

For me when it comes to useful commands xargs ranks along side commands like find, top and df; xargs is a great time saver and incredibly useful. Today I will show a few examples of usage and some of the lesser known features. Basic Usage The xargs command is used to take the output of one command and provide it as arguments to another. Example (xargs): # ls [0-9]-test.xml | xargs chmod -v 644 mode of `1-test....

 · 7 min · Benjamin Cane

Troubleshooting High I/O Wait in Linux

Linux has many tools available for troubleshooting some are easy to use, some are more advanced. I/O Wait is an issue that requires use of some of the more advanced tools as well as an advanced usage of some of the basic tools. The reason I/O Wait is difficult to troubleshoot is due to the fact that by default there are plenty of tools to tell you that your system is I/O bound, but not as many that can narrow the problem to a specific process or processes....

 · 8 min · Benjamin Cane

Cheat Sheet: 21 useful find commands

For todays article I wanted to put together a quick little cheat sheet for some GNU find command examples. Some of these commands will be basic some will be more advanced, but they all will be useful. As a caveat some commands don't work in all Unix environments and this is especially true with older releases. If you find yourself in one of those situations there is a way to make the find command work you will just need to use different methods like the -exec flag....

 · 3 min · Benjamin Cane

Adding simulated network latency to your Linux server

Have you ever said to yourself, “man I really need to slow down my internet”? Probably not very often, but recently I found myself in a dilemma where I needed to simulate 120ms of network latency in my test environment which consists of servers that are racked right next to each other. That is where the command tc comes in. Within the current distributions of Linux there is a kernel component called netem, which adds Network Emulation and is used for testing and simulating the same types of issues one would see in a WAN (Wide Area Network)....

 · 3 min · Benjamin Cane

Sar & Sysstat: Linux Performance Statistics with Ease

Whenever I perform any type of activity that requires me to look at historical system statistics such as load average, CPU utilization, I/O wait state, or even memory usage; I usually skip the System Monitoring Applications like Nagios or Zenoss and start running the sar command. While I'm not saying that sar completely replaces those tools, I am saying that sar is quick and dirty and if all you want is some raw numbers from a certain time frame; sar is a great tool....

 · 9 min · Benjamin Cane