![8vl3onvznkopxa6ny9995yrc4gw[1]](https://i0.wp.com/www.krazyworks.com/wp-content/uploads/2021/10/8vl3onvznkopxa6ny9995yrc4gw1-175x150.jpg "Awk & sed Snippets for SysAdmins")
Articles tagged with: Linux
Selecting CMS Software
If you are looking for an open-source content management system, your choices are likely to boil down to these three: Joomla!, WordPress, and Drupal. Professional CMS developers tend to disregard WordPress as a purely blogging …
SSH Login Without Password for a Linux Cluster
Most HPC cluster management utilities will automatically take care of the password-less SSH configuration. However, if you are not so lucky, here are the simple steps to get this working. Keep in mind that, depending …
Force NTP Time Update on Linux
Imagine this: you created the /etc/ntp.conf file, enabled and started the ntpd service, and… the system time is still off. Is there a way to force time sync with the NTP server? It must be your lucky day. All you have to do is to connect to your box as root and run the following command…
Server and Network Monitoring with iPhone
What is a Unix sysadmin doing with an iPhone, you ask? It was a birthday present, if that’s all right with you. I know, I should have gotten something odd with a beta version of …
How to Really Kill Computer Viruses
How do you know if your computer has a virus? Is it connected to the Internet? Then it has a virus. Many computer viruses and other malicious applications are very resilient and will actively resist any attempts to deactivate and remove them. Some viruses can even delete your antivirus application or prevent it from working properly. Many viruses cannot be effectively removed once they are loaded in memory and active.
Forcing Linux to Reboot
Until I branched out a few years ago from supporting Unix server to working with Linux clusters, I never really encountered this issue: you type “reboot”, “init 0”, or “shutdown” as root and… nothing happens. Or the system starts going down but then hangs on unmounting a filesystem or unloading a module. I think this happened once to a colleague of mine who was rebooting a Solaris server, but this is a common problem with Linux.
Working with Linux Driver Modules
You just replaced a failed network card, rebooted your server and now network wouldn’t start and your screen is filled with cryptic error messages about some kernel module doing something it’s not supposed to do. …
Slow SSH login in SuSE Linux
Starting with SuSE 10 and including both openSuSE and SLES an annoying SSH problem appeared. When you SSH to the server (via PuTTY and such) you get the “login” prompts right away, but the “password” …
How to Interview a Unix SysAdmin
“You see,” he explained, “I consider that a man’s brain originally is like a little empty attic, and you have to stock it with such furniture as you choose. A fool takes in all the …
Shell Scripting for HPC Clusters, Part 2
This is the second installment of a multipart guide for beginner Unix sysadmins supporting HPC clusters. You can view the first part of the guide here.
Searching, Replacing, Comparing
Try to work with a large cluster and …
Shell Scripting for HPC Clusters, Part 1
This is the first installment of a multipart guide for beginner Unix sysadmins supporting HPC clusters.
“For” and “While” Loop Constructs
The main challenge of supporting a Linux cluster is ensuring a homogeneous environment. Aside from small …
Controlling Process CPU Utilization
Let’s say there is a process on your Unix/Linux system that sometimes tends to consume all CPU resources and become unresponsive. At the same time, you do not want to terminate the process at the …
Encoding Videos for XBox 360 and PS3
Both Xbox 360 and PS3 support a variety of video codecs and are capable of playing high-definition video files. One of the most popular formats for HD video files is Matroska (MKV), which provides excellent …
Linux and High I/O Wait
When you look at the CPU activity of your computer, one of the parameters is the iowait. This value shows how much time your CPU wastes while it is waiting for I/O operations for complete. …
Sharing Videos from Linux to Xbox 360
Xbox 360 uses UPnP protocol to stream multimedia files from computers on your home network. Normally, you would have a Windows PC running WMP and sharing files. But what if you have a Linux box …
What’s the Best CMS
Content management systems are sprouting up like mushrooms after a warm April rain. If your job is to find the perfect CMS for your needs, you can spend weeks analyzing and comparing features of various …
Convert Images to PDF
Converting sets of images into multi-page PDF files makes it easier to organize and share them. All you need for the conversion is the free that will run on your Windows, Linux, MacOS and many other operating systems. If you are running a recent version of Linux, chances are that ImageMagick is already installed on your computer (just type “which convert” to check).
WordPress Quick Upgrade for Linux
Never ever upgrade WordPress to the latest version as soon as it comes out, unless you want to be the guinea pig dealing with the new bugs and incompatible plugins. Even if the new version …
Linksys WAP54G Secure Configuration
Below are some basic steps to secure a wireless access point (WAP). The screenshots are for Linksys WAP54G v. 3.04, however, the same steps will apply to wireless access points from other manufacturers. Understand this: …
Apache and Multiple Domains – from Home
Apparently there are folks out there who are still interested in running their own Web server from home. More than that – they want to have multiple domains. Guys, Web hosting these days is so …
Data Security and Online Privacy
You have information on your computer that you don’t want others to see. Sometimes you want to share information with someone, but you don’t want anyone to know that you are the one sharing it. Let’s say that you came across some information suggesting that your employer may be breaking law. You want to make this information public, but you can’t do it openly becausloe you will be fired. Another example: you are at work and you need to send a personal, confidential email…
Scali Manage (Platform Manager) CLI Guide
Scali Manage – the bloated and unpredictable HPC cluster management tool – has recently been acquired by Platform Computing Corp. It is to be integrated into Platform LSF and Platform OCS products. I can’t say …
![8vl3onvznkopxa6ny9995yrc4gw[1]](https://i0.wp.com/www.krazyworks.com/wp-content/uploads/2021/10/8vl3onvznkopxa6ny9995yrc4gw1-80x80.jpg "Awk & sed Snippets for SysAdmins")
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![9dwz62kvm0gtjya9kwb7pawtk9y[1]](https://i2.wp.com/www.krazyworks.com/wp-content/uploads/2021/10/9dwz62kvm0gtjya9kwb7pawtk9y1-80x80.jpg "Finding Duplicate Photos")
![tq9mhhd5xy2q0kto2j1785n6odv[1]](https://i1.wp.com/www.krazyworks.com/wp-content/uploads/2021/10/tq9mhhd5xy2q0kto2j1785n6odv1-80x80.jpg "NFS I/O Stats with Logging")
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