3. Upgrading from Previous Releases of FreeBSD

3.1. Upgrading Using freebsd-update(8) or a Source-Based Procedure

Binary upgrades between RELEASE versions (and snapshots of the various security branches) are supported using the freebsd-update(8) utility. The binary upgrade procedure will update unmodified userland utilities, as well as an unmodified GENERIC kernel, distributed as a part of an official FreeBSD release. The freebsd-update(8) utility requires that the host being upgraded have Internet connectivity.

Source-based upgrades (those based on recompiling the FreeBSD base system from source code) from previous versions are supported using to the instructions in /usr/src/UPDATING.


Upgrading FreeBSD should only be attempted after backing up all data and configuration files.

3.2. User-Visible Incompatibilities

FreeBSD 9.0 and later have several incompatibilities in system configuration which you might want to know before upgrading your system. Please read this section and the Upgrading Section in 9.0-RELEASE Release Notes carefully before submitting a problem report and/or posting a question to the FreeBSD mailing lists.

All FreeBSD documents are available for download at http://ftp.FreeBSD.org/pub/FreeBSD/doc/

Questions that are not answered by the documentation may be sent to <freebsd-questions@FreeBSD.org>.
Send questions about this document to <freebsd-doc@FreeBSD.org>.