Linux Tips, Hacks, Tricks, and Tutorials
Before you Begin Complete the steps for setting your Server / VPS hostname and timezone. Complete the steps in our Securing Your Server guide to create a standard user account, harden SSH access, and remove unnecessary network services. Update your server’s software packages:CentOS
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sudo yum update && sudo yum upgrade |
Debian / Ubuntu
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sudo apt update && sudo apt upgrade |
Download and Install Let’s Encrypt Install the […]
What is Fail2Ban? Any service that is exposed to the internet is susceptible to attacks from malicious parties. If your service requires authentication, illegitimate users and bots will attempt to break into your system by repeatedly trying to authenticate using different credentials. A common example of this is with SSH, which will be the subject […]
Download Source File This PHP API script reads Nagios status.dat file and return the JSON result. This API is desinged for Nagios Client unofficial Nagios status monitoring app. Step 1 Upload nath_status.php to your Nagios web root folder. ###Nagios Core’s 3.5.1 default Web Root folder Web Root Folder – Centos /usr/share/nagios/html/ ###Nagios Core’s default Web Root folder Web […]
If that’s what you want to do, the following hack will do it (it looks like a cleaner solution would require figuring out where the [SIGNATURE] in the email template is coming from and removing that). These instructions are for phplist version 2.10.2. Search lists/admin/sendemaillib.php for $text[“signature”] = “\n\n–\nPowered by PHPlist, www.phplist.com –\n\n”; Immediately after that line, add the line (or replace […]
This is the full step-by-step procedure to resync a master-slave replication from scratch: At the master: And copy the values of the result of the last command somewhere. Without closing the connection to the client (because it would release the read lock) issue the command to get a dump of the master: Now you can release the […]
Enviroment: – Server01.192.168.30.201 – Server02.192.168.30.202 – Directory to be Sync : “/opt/web/htdocs/prompt and /opt/vxml ” 2.Step Key based authentication Configuration -Login to Master server & generate the public and Private keys using the following command:
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[root@server01 ~]# ssh-keygen -t rsa [root@server01 ~]# ssh-copy-id -i /root/.ssh/id_rsa.pub root@192.168.30.202 |
2.Step Installation Lsyncd
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[root@server01 ~]# yum install epel-release [root@server01 ~]# yum install lsyncd -y |
3.Step Lsyncd Configuration
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settings { logfile = "/var/log/lsyncd.log", statusFile = "/var/log/lsyncd.stat", statusInterval = 2, } sync{ default.rsync, source="/opt/web/htdocs/prompt", target="192.168.30.103:/opt/web/htdocs/prompt", rsync={rsh ="/usr/bin/ssh -l appadmin -i /home/appadmin/.ssh/id_rsa",} } sync{ default.rsync, source="/opt/vxml", target="192.168.30.103:/opt/vxml", rsync={rsh ="/usr/bin/ssh -l appadmin -i /home/appadmin/.ssh/id_rsa",} } |
Start and enable the lsyncd service using the following commands:
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[root@server01 ~]# systemctl enable lsyncd [root@server01 ~]# systemctl start lsyncd |
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Backup all the database and stop mysql
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mysqldump -u (userid) -p (password) --all-databases > all-databases.sql service mysqld stop |
Download the Repo for MySql 5.6
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wget http://dev.mysql.com/get/mysql-community-release-el6-3.noarch.rpm/from/http://repo.mysql.com/ |
Install the repository from the local file
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yum localinstall mysql-community-release-el6-3.noarch.rpm |
Install the latest MySql
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yum install mysql-community-server service mysqld start |
Configure MySQL to start automatically on Server Reboot
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chkconfig mysqld on chkconfig —list mysqld |
Need to apply some tweaks Its not like the previous versions that tweaks are not required. From Version […]
Prerequisites 2 or more CentOS 7 Serverpre web01 10.0.15.10 web02 10.0.15.11 web03 10.0.15.12 Floating IP Address 10.0.15.15 Root Privileges What we will do: Map the Host File Install Epel Repository and Nginx Install and Configure Pacemaker, Corosync, and Pcsd Create and Configure the Cluster Disable STONITH and Ignore the Quorum Policy Add the Floating-IP and […]
Networking: We have two nodes that are reachable by below Networks: 10.1.1.0/24 : Cluster heartbeat vlan. 172.16.1.0/24 : LAN with access to the Internal LAN network and Internet. We have set the following hostnames:
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[master ~]# hostnamectl set-hostname master.sysadmin.lk [client ~]# hostnamectl set-hostname client.sysadmin.lk |
We defined the Hostname and IP Address in “/etc/hosts” file(On both the nodes), as shown below;
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127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4 ::1 localhost localhost.localdomain localhost6 localhost6.localdomain6 172.16.1.1 master.sysadmin.lk #Physical IP Address of NODE1 172.16.1.2 client.sysadmin.lk #Physical IP Address of NODE2 10.1.1.1 NODE1 #HeartBeat IP Addr of NODE1 10.1.1.2 NODE2 #HeartBeat IP Addr of NODE2 |
To setting up […]
I’m using two CentOS systems here: NFS Server: server.example.com, IP address: 192.168.1.100 NFS Client: client.example.com, IP address: 192.168.1.101 Configure the Firewall
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firewall-cmd --permanent --zone=public --add-service=nfs firewall-cmd --reload |
Installing NFS and enable and start the nfs server service.(Client / Server)
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yum -y install nfs-utils systemctl enable nfs-server.service systemctl start nfs-server.service |
Exporting Directories on the Server
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mkdir /var/nfs chown nfsnobody:nfsnobody /var/nfs chmod 755 /var/nfs |
Now we must modify /etc/exports where we “export” our NFS shares.
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#vim /etc/exports /home 192.168.1.101(rw,sync,no_root_squash,no_subtree_check) /var/nfs 192.168.1.101(rw,sync,no_subtree_check) #exportfs -a |
Mounting the […]