Archive for the ‘Tips and Tricks’ Category

NFS – Network File System

Network File System (NFS) is a way to share files between machines on a network as if the files are located on the client’s local hard drive. It is an effective way to share files to a group of users using the same network. e.g. a group of users are working on a project and needs to share their files stored in a particular directory. In such a case, everyone can upload/share their files in a common folder( like /project) and share it over NFS.

For the NFS service, one ( any RedHat machine with the package installed)  machine in a system works as a server while others can connect to it to fetch/share files. Sharing files from an NFS server is known as exporting the directories. A X-Windows based application is available to edit the configuration file, but since in the previous post ( OD Hardening), I already mentioned that generally X Windows is not needed in production server and should be removed, I will discuss the procedure to edit the configuration file using text editors.  (more…)

Linux systems – monitoring

Monitoring a system is an essential part of system administration and a regular monitoring/checking will only make sure that everything is in order. There are several things to monitor in a server, viz user accounts, CPU or memory loads and network traffics.

We will start with the user accounts. In the previous post I have already discussed about the security issues related to user accounts and the reason a good password policy is required and how to implement it.  Also how to check if an user is trying to use incorrect password to login or attempting for su  privilege. A few basic commands to monitor user accounts are : (more…)

Linux Comprehensive – back to basics

I am not sure about the title used in this post but I couldn’t think of a better one. Many elementary and tricky questions are asked to a Linux professional when interviewed for a job. So I wanted to accumulate as much as possible so that someone ( more for me) can go through the article and get prepared for the interview or even know about a certain thing related to Linux system administration in a quick readout. (more…)

.avi file compression

Uncompressed video files ( .avi) which are recorded from cameras or webcam use a huge file size. A 25 sec moderate quality video takes 150 mb of space. It is not possible to share this raw format with others through internet and so I was looking for a method to compress the file and keeping it as a .avi file. After searching the net and testing with a few softwares I was finally able to compress my 150mb .avi file to 5 mb without losing the framerate or quality of the video.

VirtualDub was the answer to my problem. You can download VirtualDub from here. Its a zip file which you can extract and start using by just running the file VirtualDub.exe

You will also need a Xvid Codec for the compression, a good codec is Koepi’s XviD Codec 1.2.2 which you can download and install. I got an error to override the deafult codec while installing it, but I Ignored the error and everything worked fine after that. (more…)