Backup FreeNAS ZFS Dataset to Ubuntu running ZFS

We are setting up replication of snapshots for backup purposes on FreeNAS. We setup Ubuntu server and install ZFS on it. We will use this system to receive snapshot for backup purposes. We manually generated ssh key on FreeNAS. This was done by connecting to CLI and running commands below. ssh-keygen -q -t rsa scp…

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…

Change email address from which Nagios sends messages

In some cases you want to change default email address of anonymous@hostname from which Nagios sends notifications. This can easily be done by changing following directives in Nagios configuration files. 1. Open the main Nagios configuration file nagios.cfg and edit the line containing admin_email vim nagios.cfg admin_email=nagios@localhost # change to your desired smtp address 2….

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…

Using Vagrant, VirtualBox and Ansible with CentOS 7

This would be the case when you need to test playbooks locally before using Ansible to deploy them. We assume you already have installed Vagrant, Ansible and VirtualBox. Ansible is one of many provisioners integrated with Vagrant. Lets see how it works Create Vagrant box with CentOS 7 mkdir centtest cd centtest sudo vagrant init…