Setup Database Master/Master Replication on MySQL Server

Starting on DB01 cat /etc/my.cnf [mysqld] log-bin=mysql-bin server-id=1 replicate-wild-do-table=replicateddb.% replicate-ignore-db=test [mysqld_safe] err-log=/var/log/mysqld.log pid-file=/var/run/mysqld/mysqld.pid Restart the service to apply the changes service mysqld restart Login to MySQL mysql –u root –p Create replication user account with the host set to the Slave Server’s IP.  Make sure the password is 32 characters or less! mysql> CREATE USER… Continue reading Setup Database Master/Master Replication on MySQL Server

FreeIPA Password Expiry Notification Script for Red Hat Identity Management

Hey there friends, I’ve got a quick’n’sloppy bash shell script that’s fairly useful, if you’re using a FreeIPA identity management domain on CentOS/RHEL/Scientific Linux and want to notify people via email of when their password is going to expire. The script assumes it’s being run on an IDM server system with access to the following… Continue reading FreeIPA Password Expiry Notification Script for Red Hat Identity Management

Install mod_security in Apache httpd for CentOS/RHEL/Scientific Linux

mod_security is an Apache plugin which is a good way to prevent malicious attacks on your web application and even just using the base/default configuration from the EPEL repository rpm package gives a pretty decent rule set and helps with hardening your system. mod_security is all about rule sets and looking for specific types of… Continue reading Install mod_security in Apache httpd for CentOS/RHEL/Scientific Linux

Relay Mail To Two or Multiple eMail SMTP Servers Simultaneously Using exim in Linux CentOS 6 RHEL 6

Hey there fellow Hurston students! I recently completed migrating a Windows email server running SmarterMail to a Linux server running Zimbra. One of the methods used to ensure a smoother transition over to the Zimbra system was to configure an exim mail relay to receive mail destined for my domains and deliver them to both… Continue reading Relay Mail To Two or Multiple eMail SMTP Servers Simultaneously Using exim in Linux CentOS 6 RHEL 6

IP Address Active/Passive Failover Setup in Linux CentOS 6 RHEL 6 using keepalived

Hey everyone out there in BBS land.  Your old friend Max here to dump out some knowledge on you. Imagine you’re living in a world of two systems and three IP addresses.  One of the IP addresses is really importing and if the system it’s running on explodes, you want it to come back up… Continue reading IP Address Active/Passive Failover Setup in Linux CentOS 6 RHEL 6 using keepalived

How To Setup MySQL Enterprise Monitoring with Zabbix

This article is NOT about how to setup the application called MySQL Enterprise Monitor but rather how to setup MySQL monitoring in your Zabbix Enterprise Monitoring software. Here’s how this works: – Network communication to the server provided by the Zabbix Agent. – Agent side UserParameter settings allow for needed commands to be run against… Continue reading How To Setup MySQL Enterprise Monitoring with Zabbix

Set Default Directory Permissions in Using ACLs

I’ve only tested this on RHEL/CentOS/Scientific Linux but should work on any system running Linux acl. ACL’s are useful for providing more granular file and directory access permissions as a supplement to the standard Unix user/group permissions. Let’s say you want the user ‘funboy’ to have full control over the /disco directory on your system, and… Continue reading Set Default Directory Permissions in Using ACLs

Show Some Line Numbers in vim (vi) in RHEL/CentOS/Scientific Linux

Alright check this shit out..  I’m one of those dudes who likes to have my text editors display the line number at all times.  CALL ME OLD FASHIONED! So if you want line numbers to be displayed in vi (which is really vim these days in the GNU/Linux version we’re talking about), run the following:… Continue reading Show Some Line Numbers in vim (vi) in RHEL/CentOS/Scientific Linux

How to Install Zabbix Server 2.0 on CentOS 6 or CentOS 5

So you probably know this already but RHEL and CentOS are basically the same, as in they have full binary compatibility.  Here’s how you can install a Zabbix Monitoring Server on CentOS 5 or 6 (AKA RHEL 5 or 6). As well as installing the zabbix client side packages. FIRST!  Setup the yum repo that… Continue reading How to Install Zabbix Server 2.0 on CentOS 6 or CentOS 5