Linux system monitoring and statistics gathering

We will look at some Linux commands which will help us monitor system performance, gather statistics and view historical resource usage. Monitoring connections with ss command ss should be preinstalled for most modern Linux distributions Show established TCP connection ss -t Show established UDP connections ss -u Show ports listening for TCP connections ss -ltn…

Install SoftEther server on Linux CentOS 7.2

We will take a look at hot to install SoftEther VPN on CentOS 7 and connect to it from Windows system running VPN manager. 1. We install CentOS 7 minimal with firewalld and selinux disabled. Make sure gcc is installed with all updates yum update -y yum install gcc 2. Download softether-vpnserver* package for Linux…

How to install zabbix monitoring tool on CentOS7

This is very quick how to on installing zabbix on CentOS 7. Install LAMP ‘ yum -y install httpd systemctl start httpd systemctl enable httpd yum -y install epel-release rpm -Uvh https://mirror.webtatic.com/yum/el7/webtatic-release.rpm yum -y install mod_php72w php72w-cli php72w-common php72w-devel php72w-pear php72w-gd php72w-mbstring php72w-mysql php72w-xml php72w-bcmath yum -y install mariadb-server systemctl start mariadb systemctl enable mariadb…

Integrate FreeIPA with Windows 2016 Active Directory

In this LAB we will setup Trust based integration between FreeIPA and Windows 2016 Active Directory Forest Lab Information Windows 2016 Standard CentOS 7.5.1804 FreeIPA 4.5.4 Windows domain-win.poc.lab IPA domain-lin.poc.lab Kerberos realm names = WIN.POC.LAB ; LIN.POC.LAB Required Firewall ports TCP ports: 80, 88, 443, 389, 636, 88, 464, 53, 135, 138, 139, 445, 1024-1300…

Authenticate CentOS7 to Active Directory

Here we look at the steps we need to take to authenticate CentOS7 to Active Directory 1. Install the following packages yum install sssd realmd oddjob oddjob-mkhomedir adcli samba-common samba-common-tools krb5-workstation openldap-clients policycoreutils-python -y 2. Verify correct SRV records dig -t SRV _ldap._tcp.ad.example.com 3. Join your windows domain with account that has permissions to join…

Linux CenstOS 7 and Windows 2012 R2 Authentication integration

This article will show how to integrate Windows 2012 R2 Domain with CentOS 7 or RedHat 7. After completing this steps user will be able to login to Linux system with windows AS credentials. Installing Identity Management for UNIX on Windows 2012 R2 DC by using a command line Run powershell as administrator and execute…

Using screen command to share session on Linux system

Lets take a look at how to share existing ssh session using command called screen. It is very useful in case where you have to show your users something remotely. First install screen program – We assume CentOS7 yum install screen System1 You can create multiple screen sessions or share existing on Create multiple screen…

Changing name of salt minion CentsOS 7

We run into situation when we needed to change name of already added salt minion. Here is few simple steps that will get this done. On Salt minion Stop the Salt-Minion Service systemctl stop salt-minion Delete the current keys cd /etc/salt/pki/minion/ rm -rf minion.pub minion.pem Change the minions id in /etc/salt/minion_id vim /etc/salt/minion_id myminion.prolinuxhub.com On…

Building MariaDB Master Salve replication cluster CentOS 7

Assumptions: We have 2 Linux VMs with 5.5.56-MariaDB. IP address 192.168.0.222(cluster1.local) and 192.168.0.223(cluster2.local) We have 3 existing databases on cluster1.local – mydb1, mydb2, mydb3 Setup Master (cluster1.local) Edit my.cnf file vi /etc/my.cnf bind-address = 0.0.0.0 server_id=1 log-basename=master1 log-bin replicate-do-db = mydb1 replicate-do-db = mydb2 Restart MariaDB systemctl restart mariadb Inside MariaDB prompt GRANT REPLICATION SLAVE…

Basic salt on CentOS7 both server and client

Very quick look at how to install and use Saltstack on one vm both server and minion. Also we loot at some basic commands that are needed to manage salt deployment Installing salt Salt server can be installed in many ways Option 1 (saltstack repo) yum install https://repo.saltstack.com/yum/redhat/salt-repo-latest-2.el7.noarch.rpm yum clean expire-cache yum install salt-master yum…