Linux – Page 5 – TuxFixer.com

Install and Configure KVM (Bridge Net Interface) on CentOS 7 / RHEL 7

KVM (Kernel-based Virtual Machine) is a virtualization infrastructure for the Linux which requires a processor with hardware virtualization extension to be able to host guest sytems. KVM is convenient solution to test and try different operating systems if you don’t have a possibility to purchase expensive and power consuming physical hardware.

The below tutorial presents KVM (QEMU) installation and setup along with Linux Bridge configuration on CentOS7 / RedHat7 operating system.
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Linux

Install and Configure Elasticsearch Cluster on CentOS 7 nodes

Jun 18, 2016 by Grzegorz Juszczak 0 Comments 3 node elastic search, 3 node elasticsearch cluster, configure elasticsearch centos 7, elasticsearch centos 7 configuration, elasticsearch centos 7 installation, install elasticsearch 3 nodes, install elasticsearch centos 7, setup elasticsearch centos 7, setup elasticsearch three nodes, three node elastic search, three node elasticsearch cluster

Elasticsearch is a search server/engine based on Apache Lucene. It provides a multi-node distributed full-text search engine with an HTTP web interface and sophisticated RESTful API. Elasticsearch is developed in Java and is released as open source under the terms of the Apache License.

There are several types of nodes in Elasticsearch architecture:

Master-eligible node – eligible to be elected as Master node, which controls the cluster.
Data node – holds data and performs data related operations such as search, and aggregations
Client node – acts as a “router” forwarding cluster-level requests to the master node and data-related requests (such as search) to the data nodes
Tribe node – special type of client node that can connect to multiple clusters and perform data-related operations across clusters

In this tutorial we will install Elasticsearch Cluster on three Centos 7 based nodes: Master-eligible node, Data node and Client node.
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Linux

How to Enable SSH Service in Manjaro Linux

Jun 14, 2016 by Grzegorz Juszczak 5 Comments configure ssh manjaro linux, enable ssh manjaro linux, install configure ssh manjaro, launch ssh server manjaro, manjaro linux ssh service, manjaro start ssh server, start ssh daemon manjaro

How to enable SSH Server in Manjaro Linux?

Below I present how to enable and launch SSH service on Manjaro Linux, based on CinderCloud VPS, in a few simple steps:
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Linux, Virtualization

virt-what: Check if your remote server runs in virtual environment

May 13, 2016 by Grzegorz Juszczak 0 Comments check if server virtual, check if virtual machine, check vps with virt-what, detect if virtual machine, verify if server virtual, virt-what check bare metal, virt-what check virtualization type

Have you ever wondered if the server you bought at the hosting provider is in fact a dedicated server or just a VPS and what is the underlying virtualization environment your server runs on?
virt-what provides us the ability to detect if we are running in a virtual machine or on bare-metal (real hrdware). virt-what detects common types of virtualization: hyperv, kvm, openvz, qemu, virtualbox, vmware, xen, etc…
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Linux, Security

Scan Remote Host for Open Ports using nmap Port Scanner

May 12, 2016 by Grzegorz Juszczak 0 Comments nmap commands os detection, nmap detect operating system, nmap detect remote services, nmap port scanner scan, nmap scan ip range, nmap scan localhost ports, nmap tutorial scan ports, scan host open ports, scan remote host ports, scan whole subnet nmap

nmap (Network Mapper) is an open source tool for network exploration and security auditing and a powerfull port scanner. It can be used locally on localhost as netstat alternative, but it’s main use case is to scan remote hosts for open ports, system type, running services, etc…
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Bash, Linux

Linux cp mv overwrite without prompt (disable interactive mode)

May 10, 2016 by Grzegorz Juszczak 1 Comments cp mv disable interactive, cp mv no prompt, linux copy disable interactive, linux copy prompt overwrite, linux cp mv overwrite, linux mv disable interactive, linux mv prompt overwrite

Some Linux distributions (for example: RedHat) have aliases configured in the system, especially for root user, which modify basic command line operations like: cp, mv by adding “-i” parameter to prevent user from accidental overwriting or deleting files (interactive mode). This can be disturbing, especially when we are dealing with many files at a time. To get rid of this issue we can modify aliases in the system to disable interactive mode.
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Linux, Security

Encrypt Linux Partition using LUKS cryptsetup

Apr 21, 2016 by Grzegorz Juszczak 1 Comments centos encrypt luks cryptsetup, centos encrypt partition cryptsetup, centos encrypt volume cryptsetup, centos encrypted partition cryptsetup, cryptsetup luksformat luksopen luksaddkey, data privacy partition encryption, red hat encrypt volume, redhat encrypt volume partition

LUKS (Linux Unified Key Setup) is encryption standard designed for Linux to encrypt Linux volumes or partitions. The implementation of LUKS is based on cryptsetup script as a basic disk encryption backend tool.

In this tutorial we will create Linux partition on KVM based CentOS 7, encrypt partition using LUKS cryptsetup and mount it permanently in particular mount point.
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Linux, Storage

Extend LVM Volume Group with the new Hard Disk

Apr 9, 2016 by Grzegorz Juszczak 0 Comments add new disk lvm, add physical volume lvm, add volume to lvm, extend lvm volume group, lvm add new disk, lvm add physical volume

Extend LVM Volume Group
One of the benefits of LVM (Logical Volume Manager) is the possibility to extend LVM based storage by adding new Physical Volumes which together form LVM Volume Group. Adding new Physical Volume increases the capacity of the whole Volume Group by the capacity of that particular Physical Volume and can be performed online without any outages in LVM activity.
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Linux, Storage

Backup and Restore Logical Volume using LVM Snapshot

Apr 9, 2016 by Grzegorz Juszczak 0 Comments backup volume using snapshot, create snapshot logical volume, lvm backup logical volume, lvm backup restore snapshot, lvm backup volume snapshot, lvm create volume snapshot, lvm merge volume snapshot, restore volume from snapshot

Backup Restore LVM using Snapshot
LVM (Logical Volume Manager) gives us the ability to create Snapshots. LVM Snapshot is a logical volume that temporarily preserves the original data of changing logical volume, so it’s data can be backed up preserving consistency. Snapshot must be created prior to any critical modifications on the Logical Volume in order to fulfill it’s role.

Note: Snapshot Volume needs to be large enough to store the data that will change while it exists. If more data changes than the Snapshot can hold, the Snapshot will become unusable. That means we have to “predict” how much data will be changed on the original Volume while the Snapshot exists to let the Snapshot hold all those data changes.
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Linux

Install Nagios Core from RPM on CentOS 7 / RHEL 7

Mar 15, 2016 by Grzegorz Juszczak 4 Comments install nagios core redhat 7, install nagios rpm centos 7, nagios core rpm installation, nagios installation centos 7, nagios installation from rpm, nagios installation redhat 7, nagios rpmfind install, setup nagios centos 7

Nagios is a free software, which offers monitoring and alerting services for servers, switches, applications and services.

This tutorial describes simple Nagios Core and Nagios Plugins installation from rpm packages on CentOS 7 / RedHat 7. There is no need to configure and compile Nagios Core tar.gz based source files unless you really need the newest version.
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Category: Linux