HOWTO: upgrade OpenLDAP from a major release to another
Just for reference for future upgrades.
Today I managed to upgrade from OpenLDAP 2.2.29 to OpenLDAP 2.3.11. This is a large upgrade, so all and foremost thing is to backup. Additionally, to keep downtime as less as possible, build these stuff first!
On FreeBSD, the recommended way of installing third party software is to use ports(7). Note that OpenLDAP is separated into two ports, openldap2X-server and openldap2X-client, and building the server requires the client library, therefore, you can not easily do build on the production server (and this SHOULD be avoided anyway).
A solution is to use a separated box (or jail for smaller deployments), to build packages and use pkg_add to install them.