The Best Scripting/Programming Language to learn

The best scripting or programming language to learn depends on your goals and what you want to do with it. Here are a few popular choices and their uses:

Python: Python is a general-purpose, versatile and popular programming language. It's a great language for beginners as it has a simple and easy-to-read syntax. It is also widely used in scientific computing, data analysis, artificial intelligence, and back-end web development.

Difference between rpm and yum in RHEL/Centos/Oracle Linux

RPM (Red Hat Package Manager) and Yum (Yellowdog Updater Modified) are both package management tools used in Red Hat Enterprise Linux (RHEL), CentOS, and Oracle Linux to install, update, and remove software packages.

RPM is a low-level package management tool that is used to install, update, and remove individual software packages. It can be used to install packages from local or remote sources, and it works with files that have the ".rpm" extension.

Yum is a higher-level package management tool that is built on top of RPM. It is used to manage groups of software packages and their dependencies. It can automatically resolve dependencies and install all necessary packages, Yum can also automatically update all packages on the system, and it can also remove unnecessary packages. It works with repositories, which are collections of RPM packages that are stored on a server and can be accessed over a network.

To configure rsyslog server and client in Linux

In this post we will discuss how to configure rsyslog server and client in Linux. rsyslog utility is used to log the system activities in a remote system.This facility is used for troubleshooting any remote server issues ,that has been hacked by a hacker or in the situation like remote system goes down due to sudden hardware failures.

Access Control List in Linux

Files and directories have permissions by default,different permission to owner,group and others.These default permissions are set by the umask value.
To grant different permissions for different users, access control list is used. ACL is supported by RedHat Linux kernel with ext3,ext4 and NFS mounted file systems.ACL also recognized by samba file system shares configured on ext3 or ext4 file systems.

Swap space management in Linux

Swap space, also known as virtual memory, is an area on a hard drive that Linux uses to store data that would otherwise be stored in RAM. It is used when the system runs out of physical memory (RAM) and is used to temporarily store data that is not currently being used by the system.

Ports administration and Troubleshooting

There are two types of ports 

Software port: It is a piece of software in a machine used to communicate with remote application.

Hardware port: It is a physical peripheral in a machine used to connect systems and devices physically.

NFS-Server and Client configuration in Linux

NFS- Network File System is the commonly used to share files over the network.It is widely used in UNIX-Linux based environments. NFS protocol is also used in Netapp storage for importing files to clients. NFS came across various improvements from verisons 1,2,3 and 4.
NFS 4.1 is in development stage.

RPM commands in Linux

RPM code is used for Linux like operating system ( RHEL , Centos ,Fedora) to build,query,install,update,verify and erase individual software packages.RPM package also contains detailed information about the package version modification,release date,depends on etc.Local rpm package database is stored at /var/lib/rpm ,contains information about file attributes and package dependencies.

To configure log on banner for ssh clients

SSH(Secure shell protocol ) is used to connect UNIX based machines remotely. ssh protocol  encrypts the Data connection between server and client. It uses port no 22.

While connecting servers remotely we can set banners to display in command line which includes server details and any access rights and issues. This is possible only in ssh protocol version 2 and initially no banners are configured.

Difference between NFS3 and NFS4

Here I have listed some major differences between NFS3 and NFS4.Security has been major improvement taken into account for developing NFS4 version.Version NFS 4.1 is in development stage includes pNFS mechanism.

Monitoring Tools for Linux

Here in this post I have explained few performance monitoring tools in Linux.These commands are very important for Linux system administrator to perform day to day activities to troubleshoot performance issues in server.

Sar Command in Linux

SAR (System Activity Monitor) command, frequently used monitoring command in Linux and Unix flavors. sar utility provided by the sysstat package in Linux.

In top we can view the real time analysis (CPU, Memory, load) when we logged into the server. But sar can be used to log the historical events in the server to analyze the bottlenecks with respect to CPU, Memory and load averages in the past.

Top command in Linux

The top command in Linux used to display the real time process activity of a running system. By default it list the high CPU intensive task processes. Process values are changed every 3 sec by default.

Top command displays the system uptime, Memory/CPU/Swap usage, no of users logged in and total no of processes running.