Tag Archives: linux news

How to use parallel ssh (PSSH) for executing ssh in parallel on a number of Linux/Unix/BSD servers

How to use parallel ssh (PSSH) for executing ssh in parallel on a number of Linux/Unix/BSD servers
Recently I come across a nice little nifty tool called pssh to run a single command on multiple Linux / UNIX / BSD servers. You can easily increase your productivy with this SSH tool.

More about pssh

pssh is a command line tool for executing ssh in parallel on some hosts. It provides specialties includes:

  1. Sending input to all of the processes
  2. Inputting a password to ssh
  3. Saving output to files
  4. IT/sysadmin taks automation such as patching servers
  5. Timing out and more

Let us see how to install and use pssh on Linux and Unix-like system.

pssh-welcome
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How to forcefully shutdown a guest VM using virsh command on Linux KVM

How to forcefully shutdown a guest VM using virsh command on Linux KVM

I used the command ‘virsh shutdown vm1’ to shut down a guest named vm1 using the virsh command. However, it is still running, and my vm1 is not responding to an ssh session. Is there is a way to forcefully stop or kill a guest VM using the virsh command from host server?
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How to find all hard links in a directory on Linux

How to find all hard links in a directory on Linux

I have a file named /etc/passwd i and I would like to find all hard links to this file in a directory. How do I find out all other hard links to the /etc/passwd in /backups/ directory? How can find all hard links to a given file using Linux or Unix command line option?
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How to set rsync speed limit from eating all bandwidth with –bwlimit option

How to set rsync speed limit from eating all bandwidth with –bwlimit option

The rsync command is eating all my bandwidth from a backup script and generating tons of I/O. How do I set a limit for file transfer speed of rsync command on Linux or Unix-like system? How can I keep my rsync script from using all of my bandwidth?
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How to display cpu wise usage using top command on FreeBSD Unix operating system

How to display cpu wise usage using top command on FreeBSD Unix operating system

I recently switched from Linux to FreeBSD. On Linux, I press 1 which show me a breakdown of CPU usage per CPU, but it is not working on FreeBSD. How do I find out the usage of individual CPU core usage using the top command on FreeBSD operating system?
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7 Awesome Open Source Build Automation Tools For Sysadmin/DevOps/Developers

7 Awesome Open Source Build Automation Tools For Sysadmin/DevOps/Developers
Build automation is a vital tool for devops, sysadmins, and developers. It is nothing but scripting or automating the process of compiling source code into binary. Sysadmins can use build tools to manage and update config files. Following is a list of awesome open source and popular tools associated with automating build processes on Linux or Unix-like system.

Build automation tools.
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How to add an extra second hard drive on Linux LVM and increase the size of storage

How to add an extra second hard drive on Linux LVM and increase the size of storage

I have 250GB disk installed on my home Linux server. I just bought a brand new 250GB SATA disk and I want to add a new disk to my existing LVM volume to increase its size total size to 500GB. How do I add a disk to LVM and extend an LVM volume on Linux operating system?
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How to install and configure Varnish cache on Ubuntu Linux 16.04 LTS

How to install and configure Varnish cache on Ubuntu Linux 16.04 LTS

How do I install Varnish Cache server to improve the performance of my existing Apache web server especially caching dynamic content on Ubuntu Linux 16.04 LTS server?
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How to protects Linux and Unix machines from accidental shutdowns/reboots with molly-guard

How to protects Linux and Unix machines from accidental shutdowns/reboots with molly-guard
Oops! I did it again. I thought I was logged into my home server. Turns out I rebooted the db server. Another my not so favorite is typing “shutdown -h 0” into the wrong terminal. I know a few people who have admitted to doing that here.

My anger that can't be contained
Is there any end to the madness? Do I need to suffer from accidentally random reboots and shutdowns? After all, it is human nature to make mistakes, but one should not keep on making the same mistakes again and again.
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How to create a new config file in Ansible playbook

How to create a new config file in Ansible playbook
I wanted to create a file named /etc/apt/apt.conf.d/1000-force-ipv4-transport with the value set to ‘Acquire::ForceIPv4 true;’ on 20 cloud servers hosted in AWS. I already setup Ansible playbook to automate stuff. How do I create a new file using Ansible playbook? Is it possible to create a complex file with many lines of text (say squid.conf) using Ansible IT automation tool?
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