My OpenLDAP Online Configuration (OLC) Reference provides the OLC equivalents of the configuration file options. It should be pretty accurate as I read the source code to determine which OLC attributes correspond to the configuration file options. For a description of what the various options do, consult the appropriate man page or the official Administrator’s… Read More »
The OpenLDAP memberOf overlay automatically creates and removes attributes when attributes of other entries that refer to their DN are added and removed. That statement, while technically accurate, was confusing to me and I wrote it! For example, if you create a groupOfNames entry with a member attribute of uid=user,ou=users,dc=tylersguides,dc=com, the memberOf overlay can automatically… Read More »
Mounting a Windows share on Linux is pretty straight forward. You need a Windows user that can access the shares, the name of the work group or domain, and the name of the share. First, make sure you have mount.cifs installed, then create a credentials file, and finally mount the share. You can also add… Read More »
How the hostname is set is operating system specific. This is because the hostname is typically set by the startup process, and different operating systems have different startup processes. CentOS is no different. CentOS 7 uses systemd, while CentOS 6 uses upstart. This means how to change the hostname in CentOS depends on which major… Read More »
There are several ways to install an RPM on CentOS. This guide covers the command line programs yum and rpm. There are GUI tools, such as PackageKit, to manage packages, but since the command line tools will always be available, those are what I will cover. In most cases, you probably want to use yum.… Read More »
There are two main ways to delete a file on a Linux based operating system. Keep in mind that removing a file as described in this guide just removes references to the underlying storage system. Forensic tools may be able to recover their contents. There are ways to delete files that prevent their recovery, but… Read More »
Rsync backups are versatile. You can can create full, differential and incremental backups of a directory. Rsync can backup files locally or remotely. Local Backups If you are backing up to another directory, removable storage, or a locally mounted network file system, then you will be creating local backups. Creating Local Backups To create a… Read More »
To temporarily disable SELinux on CentOS 7, run this command as root: root@centos7 ~]# setenforce 0 If you want to turn it back on, use the command: root@centos7 ~]# setenforce 1 This will not persist across a reboot. If you want it to be disabled when the system boots, edit /etc/sysconfig/selinux and replace this line:… Read More »
OpenLDAP Multi-Master Replication is for high availability, not load balancing. If a split-brain is possible, consider the mirror mode architecture described in the OpenLDAP Administrator’s Guide. A split-brain is where two or more nodes of a cluster are operating independently, which can cause the cluster data to become corrupt or out of sync. If you… Read More »
This guide will walk you through setting up CentOS 7 to use an LDAP directory server for authentication. This guide will not work with CentOS 8. If you want to use LDAP authentication with CentOS 8, click here. I am assuming you have a directory server up and running. If you don’t, you can follow… Read More »