First of all, do a final update of the system in its current version.
root@freebsd> freebsd-update fetch install ~
Looking up update.FreeBSD.org mirrors... 3 mirrors found.
Fetching metadata signature for 9.0-RELEASE from update5.FreeBSD.org... done.
Fetching metadata index... done.
Inspecting system... done.
Preparing to download files... done.
No updates needed to update system to 9.0-RELEASE-p5.
If there was an update, reboot.
Then start the upgrade:
root@freebsd> freebsd-update upgrade -r 9.1-RELEASE ~
Looking up update.FreeBSD.org mirrors... 3 mirrors found.
Fetching metadata signature for 9.0-RELEASE from update5.FreeBSD.org... done.
Fetching metadata index... done.
Inspecting system... done.
The following components of FreeBSD seem to be installed:
kernel/generic world/base
The following components of FreeBSD do not seem to be installed:
src/src world/doc world/games world/lib32
Does this look reasonable (y/n)? y
Fetching metadata signature for 9.1-RELEASE from update5.FreeBSD.org... done.
Fetching metadata index... done.
Fetching 1 metadata patches. done.
Applying metadata patches... done.
Fetching 1 metadata files... done.
Inspecting system... done.
Fetching files from 9.0-RELEASE for merging... done.
Preparing to download files... done.
Fetching 9407 patches.....10....20....30....40....50....60....70....80....90....100....110....120....130....140....150....160....170....180....190....200....210....220....230....240....250....260....270....280....290....300....310....320....330....340....350....360....370....380....390....400....410....420....430....440....450....460....470....480....490....500....510....520....530....540....550....560....570....580....590....600....610....620....630....640....650....660....670....680....690....700....710....720....730....740....750....760....770....780....790....800....810....820....830....840....850....860....870....880....890....900....910....920....930....940....950....960....970....980....990....1000....1010....1020....1030....1040....1050....1060....1070....1080....1090....1100....1110....1120....1130....1140....1150....1160....1170....1180....1190....1200....1210....1220....1230....1240....1250....1260....1270....1280....1290....1300....1310....1320....1330....1340....1350....1360....1370....1380....1390....1400....1410....1420....1430....1440....1450....1460....1470....1480....1490....1500....1510....1520....1530....1540....1550....1560....1570....1580....1590....1600....1610....1620....1630....1640....1650....1660....1670....1680....1690....1700....1710....1720....1730....1740....1750....1760....1770....1780....1790....1800....1810....1820....1830....1840....1850....1860....1870....1880....1890....1900....1910....1920....1930....1940....1950....1960....1970....1980....1990....2000....2010....2020....2030....2040....2050....2060....2070....2080....2090....2100....2110....2120....2130....2140....2150....2160....2170....2180....2190....2200....2210....2220....2230....2240....2250....2260....2270....2280....2290....2300....2310....2320....2330....2340....2350....2360....2370....2380....2390....2400....2410....2420....2430....2440....2450....2460....2470....2480....2490....2500....2510....2520....2530....2540....2550....2560....2570....2580....2590....2600....26... (line truncated to 2000 chars)
Applying patches... done.
Fetching 125 files...
The following files will be removed as part of updating to 9.1-RELEASE-p0:
... (lots of output)
The following files will be added as part of updating to 9.1-RELEASE-p0:
... (lots of output)
The following files will be updated as part of updating to 9.1-RELEASE-p0:
... (lots of output)
To install the downloaded upgrades, run "/usr/sbin/freebsd-update install".
Now install the kernel:
root@freebsd> freebsd-update install
Installing updates...
Kernel updates have been installed. Please reboot and run
"/usr/sbin/freebsd-update install" again to finish installing updates.
Reboot as instructed to load the new kernel, then install userspace:
FreeBSD 9.1-RELEASE (GENERIC) #0 r243825: Tue Dec 4 09:23:10 UTC 2012
Welcome to FreeBSD!
Before seeking technical support, please use the following resources:
o Security advisories and updated errata information for all releases are
at http://www.FreeBSD.org/releases/ - always consult the ERRATA section
for your release first as it's updated frequently.
o The Handbook and FAQ documents are at http://www.FreeBSD.org/ and,
along with the mailing lists, can be searched by going to
http://www.FreeBSD.org/search/. If the doc package has been installed
(or fetched via pkg_add -r lang-freebsd-doc, where lang is the
2-letter language code, e.g. en), they are also available formatted
in /usr/local/share/doc/freebsd.
If you still have a question or problem, please take the output of
`uname -a', along with any relevant error messages, and email it
as a question to the questions@FreeBSD.org mailing list. If you are
unfamiliar with FreeBSD's directory layout, please refer to the hier(7)
manual page. If you are not familiar with manual pages, type `man man'.
Edit /etc/motd to change this login announcement.
root@freebsd> freebsd-update install
Installing updates... done.
At this point there are two possibilities. Either you get no message, in which case you’re done (this applies to migrations from FreeBSD 8.3 and above), or you’re asked to rebuild the ports. This rebuilds your ports against the new libraries. If you use portupgrade:
portupgrade -Raf
If you use portmaster:
portmaster -af
Reboot once the ports are rebuilt and run freebsd-update install again to clean up obsolete libraries.