Upgrade to new release

This article takes upgrading system from 10.2-RELEASE to 10.3-RELEASE as an example, but you must notice this tutorial may not apply to other versions. So please read the related release notes.

(1) Check current version:

# freebsd-version -ku
10.2-RELEASE
10.2-RELEASE

(2) Run "freebsd-update upgrade" command to upgrade current system to a new version:

# freebsd-update upgrade -r 10.3-RELEASE
......
To install the downloaded upgrades, run "/usr/sbin/freebsd-update install".

(3) The last log of "freebsd-update upgrade -r 10.3-RELEASE" prompts executing "freebsd-update install":

# freebsd-update install
src component not installed, skipped
Installing updates...
Kernel updates have been installed.  Please reboot and run
"/usr/sbin/freebsd-update install" again to finish installing updates.

(4) Reboot the system and execute "freebsd-update install" again:

# reboot
# freebsd-update install
src component not installed, skipped
Installing updates... done.

(5) Now check the version:

# freebsd-version -ku
10.3-RELEASE-p4
10.3-RELEASE-p5

The system has been upgraded to 10.3-RELEASE now.

Reference:
freebsd-update;
FreeBSD 10.3-RELEASE Installation Instructions.