After reading this post you will know which services need to be restarted after updating one or more RPM packages. Also, you will know if a server reboot is needed after updating one or more RPM packages. needs-restarting utility of yum The command /sbin/needs-restarting out of the package yum-utils compares the mapped libraries of the […]
Archives for November 2018
11 Useful “ssh” and “scp” Commands in Linux
Introduction In this post, we are going to learn some useful ssh command and scp command with examples. SSH is a protocol that stands for Secure Shell which is a client-side command tool used to take remote session of Linux system securely. It uses Symmetrical and Asymmetrical encryption method to transfer data over the network. […]
6 Bash Shell Command Line Chaining Operators in Linux
Introduction In this article, I will explain you 6 Bash shell command line Chaining Operators (Linux operator). Now let’s discuss what is chaining operator. Chaining operator is something which helps to run multiple commands at once like we execute a script and task completes automatically. Usually, people use Bash shell command line Chaining Operators (Linux […]
14 Useful “cat” Command Examples in Linux
Intoduction When learning Unix, it’s common to first learn the cat command. An easy abbreviation to remember if you are pet-friendly, this command will concatenate the elements you specify into one package. The easiest way to look at files is to use cat, the concatenate command. In this article, we are going to learn how […]
The System Activity Reporter (sar) Command in Linux
The System Activity Reporter, sar, can display a lot of information about your computer and save that information to files for later analysis. This program and its related tools are part of the sysstat package. When you install sysstat, a file named sysstat is added to the /etc/cron.d/ to call sar automatically. On Debian and […]
How to find which specific ethernet device corresponds to a specific port on a multi-interface network card in CentOS/RHEL
The Ask Can the Linux OS determine which physical port on a multi-interface network card an active ethernet device in the Linux OS corresponds to? The Answer There is no direct or guaranteed way to do this via the Linux OS, as it can depend on the server and network card hardware and firmware, however, […]
Linux OS Service ‘kudzu’
Service Name kudzu Description This executes kudzu, the automatic hardware detection tool developed by Red Hat. “kudzu” detects and configures new and/or changed hardware on a system. It loads the required drivers and unloads redundant drivers. It is configured by default to run at system boot time to determine what hardware has been added or […]
Linux OS Service ‘lm_sensors’
Service Name lm_sensors Description The lm_sensors is a service, set up to monitor hardware like CPU temperature or fan speed. Not all system hardware provides the necessary sensor hardware resource for the lm_sensors service to be useful. Later lm_sensor packages include the sensors_detect utility, which can be used to probe which sensors your hardware provides […]
Input/Output Errors During XFS Filesystem Access In CentOS/RHEL 7
The Problem While accessing a directory mounted on XFS filesystem, it is throwing Input/Output errors on any command as in the example below: [root@OL7-VM mnt]# cd /u01 [root@OL7-VM u01]# ll ls: cannot open directory .: Input/output error [root@OL7-VM u01]# cd /mnt [root@OL7-VM mnt]# ll ls: cannot open directory .: Input/output error The Solution It appears […]