This was posted originally on 2018. Updated few. Why this topic? SSH, secure shell, is a network protocol used to access remote Linux machine. You can execute commands on the remote server by connecting using SSH protocol. SSH, it’s an…
Tag: Security
How to replace a failed harddrive in a software RAID 1 array?
Is it possible to replace a faulty drive from RAID 1? What are the steps? Here I’m explaining the detailed steps in replacing a bad drive from software RAID 1 array. As you know RAID 1 means mirroring. Here I’ve…
What is Semaphore? Why it’s important for a Server Admin?
What is Semaphore? Well, we need a discussion on Semaphore concept under Linux as it plays major role in a Multi Processing System. Some time we need to review the current Semaphore status on the server and need to kill unwanted/unused…
Sar command usage with examples in Linux
Sar is one of the smart command line utility in Linux. Also, System Activity Reporter (SAR) is one of the important tool to monitor Linux servers.This command will helps system administrators to check the server resources status at different time…
CSF commands to allow/deny IP addresses for temporary – Command line option
CSF is one of the best firewall application for your Linux based servers. We have already dicussed a lot about CSF and its command usages. Refer this to Install CSF on your server. We have a lot of options available…
How to open a port for a particular IP address using iptables, CSF and APF – A comparison
This is a very important and useful trick to block some ports from public. And open it for some IP address. It’s quite simple by configuring iptables with the help of applications like CSF or APF. By using iptables commands, blocking…
Managing Firewalld on CentOS/RHEL 7 – start/stop/status-check
Hey, I’m new here and unable to manage my Firewall daemon on my server/VPS. The OS is reloaded with latest CentOS 7. Yeah, it’s a little bit new, managing services on CentOS/RHEL 7 servers. The daemon for iptables is firewalld…