Linux is an open-source operating system (OS). An operating system is software that directly manages a system’s hardware and resources, like CPU, memory, and storage. The OS sits between applications and hardware and makes the connections between all of your software and the physical resources that do the work. Here, at https://blog.eduguru.in, We will discuss and solve real-life problems coming on Linux OS. We also know more interesting features of Linux here.
Generally setup command is not used to install in centos minimal installation: Here is the step to install setup command in centos: # yum install setuptool -y # yum install system-config-network* -y # yum install system-config-firewall* -y # yum install system-config-securitylevel-tui -y # yum install system-config-keyboard -y # yum install ntsysv -y
Being a network administrator requires a deep knowledge about remote login protocols such as rlogin, telnet and ssh. The one I will discuss in this article is ssh, a secure remote protocol which is used to work remotely on other machines or transfer data between computers using SCP (Secure Copy) command. But, what is OpenSSH and how to install it in your Linux distribution? … Read more
Check the Status of The Iptables IPv4 Firewall Run the following command to check the status of the iptables IPv4 firewall : # service iptables status Disable The Iptables Firewall Use the following commands to stop the Iptables Firewall and remove it from autostart. Disable The Iptables IPv4 Firewall Run the following commands to stop the iptables firewall … Read more
SSH- SECURE SHELL It is used to Connect to the remote system through secure shell. It giveyou a copy of remote shell on your desktop.You can also create password less login to the remote system with the help of PUBLIC/PRIVATE keys. 1.For installing SSH open the terminal and type :- # su <— to become root and enter the password> # yum install openssh-server 2. After the completion of … Read more
Mounting a Windows (cifs) share on centos gives us a “Mount.cifs cannot allocate memory” error. Executing a command like this: mount -t cifs //toad/Backup /media/backup -o user=username,password=password,iocharset=utf8,file_mode=0777,dir_mode=0777 We get an error like this: mount error(12): Cannot allocate memory Refer to the mount.cifs(8) manual page (e.g. man mount.cifs) Solution: First, check the permissions on your shared … Read more
What is a runlevel ? Runlevel is the preset state in which a Linux system operates. Below mentioned are the different runlevels of a Linux system in which a linux system can be operated 0- halt or shutdown 1- single user mode 2- multi user mode without NFS 3- full multi-user mode 4- not used … Read more
To change the hostname, follow the steps shown below. 1. Use hostname command to Change Hostname In this example, we’ll change the hostname from dev-server to prod-server. hostname command by default will display the current hostname as shown below: # hostname dev-server The following will change the hostname to prod-server. # hostname prod-server Once the … Read more
top provides an ongoing look at processor activity in real time. It displays a listing of the most CPU-intensive tasks on the system, and can provide an interactive interface for manipulating processes. It can sort the tasks by CPU usage, memory usage and runtime. can be better configured than the standard top from the procps suite. … Read more
Multi-core CPU processors are common nowadays, including dual-core processors (e.g., Intel Core Duo), quad-core processors (e.g., Intel Core i5), and hexa-core processors (e.g., AMD Phenom II X6). Also, many server-grade physical machines are equipped with more than one CPU processor. To find the number of physical CPUs: $ cat /proc/cpuinfo | grep “^physical id” | … Read more
WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ @ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY! Someone could be eavesdropping on you right now (man-in-the-middle attack)! It is also possible that the RSA host key has just been changed. The fingerprint for the RSA key sent … Read more