by SathiyaMoorthy
on May 10, 2011
Anacron is the cron for desktops and laptops.
Anacron does not expect the system to be running 24 x 7 like a server.
When you want a background job to be executed automatically on a machine that is not running 24 x 7, you should use anacron.
For example, if you have a backup script scheduled everyday at 11 PM as a regular cron job, and if your laptop is not up at 11 PM, your backup job will not be executed.
However, if you have the same job scheduled in anacron, you can be sure that it will be executed once the laptop come back up.
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by Ramesh Natarajan
on May 2, 2011
As we discussed in our Linux performance monitoring introduction article, measuring IO subsystem performance is very important.
If someone is complaining that a database (or any application) running on one server (with certain filesystem, or RAID configuration) is running faster than the same database or application running on another server, you might want to make sure that the performance at the disk level is same on both the server. You can use iozone for this situation.
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by Sasikala
on April 25, 2011
SVN stands for Subversion.
Subversion is a free/open-source version control system. Subversion manages files and directories over time. A tree of files is placed into a central repository. The repository is much like an ordinary file server, except that it remembers every change ever made to your files and directories. This allows you to recover older versions of your code, or examine the history of how your code was changed.
This article explains some basic SVN commands with examples.
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by Ramesh Natarajan
on April 18, 2011
Question: How do I identify my file system type? I like to upgrade my current file system to the latest ext4. Before that I would like to know what my current file system type is for various mount points I have on my UNIX system.
Answer: Use any one of the five methods mentioned below to identify your file system type.
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by Sasikala
on April 12, 2011
Process is a running instance of a program. Linux is a multitasking operating system, which means that more than one process can be active at once. Use ps command to find out what processes are running on your system.
This article explains 7 practical usages of ps command and its options.
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by Ramesh Natarajan
on April 6, 2011
If you are spending lot of time on UNIX / Linux, you’ll be manipulating text files frequently. You may be making the similar edits on multiple configuration files on one or more servers. You may be digging huge log files (or data files) looking for certain information.
Sed and Awk 101 Hacks is a downloadable eBook that contains 101 practical examples on various advanced Sed and Awk features, and I promise it will help you understand everything you need to know about Sed and Awk.
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by Ramesh Natarajan
on March 29, 2011
Using sar you can monitor performance of various Linux subsystems (CPU, Memory, I/O..) in real time.
Using sar, you can also collect all performance data on an on-going basis, store them, and do historical analysis to identify bottlenecks.
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by Ramesh Natarajan
on March 28, 2011
For the past several months, I’ve been working on writing a book on the two great UNIX tools — Sed and Awk.
I’ve spend lot of sleepless nights to make this book easy to read and understand with lot of examples. It is almost complete and the book will be released very soon. Once you understand how to use Sed and Awk effectively, you’ll be knocking down lot of complex text manipulation tasks just by writing few lines of Sed or Awk code.
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My name is Ramesh Natarajan. I will be posting instruction guides, how-to, troubleshooting tips and tricks on Linux, database, hardware, security and web. My focus is to write articles that will either teach you or help you resolve a problem. Read more about