I have 8.0-RELEASE-p4 + few ports installed. I wonder wheather I should update to 8.1.How long is 8.0 supported?How to update the system? I couldn't find anything about it in handbook.SOLUTION (based on gvkv answer): I take the liberty of describing all steps I've done at the end: # STEP 1: Revert to GENERIC kernelcd /tmp wget -r ftp://ftp.freebsd.org/pub/FreeBSD/releases/i386/8.0-RELEASE/kernels/cd pub/FreeBSD/releases/i386/8.0-RELEASE/kernels/sha256 generic.* install.sh | diff - CHECKSUM.SHA256./install.sh GENERICnextboot -k GENERIC# STEP 2: Upgrade - part 1freebsd-update upgrade -r 8.1-RELEASE # Ignore kernel warning. Fix configurationfreebsd-update installshutdown -r now# STEP 3: Upgrade - part 2nextboot -k GENERICfreebsd-update installshutdown -r now# STEP 4: Upgrade - part 3rm -rfv /usr/objportmaster -Raf # Rebuilds all packages. If you don't use portmaster use other tool or do it manuallycd /usr/srcmake buildkernel KERNCONF=CUSTOM # Rebuild kernelmake installkernel KERNCONF=CUSTOM # Install kernelshutdown -r now
Updating FreeBSD 8.0 to 8.1 (methods and policy)
freebsd;upgrade
The 8.0-RELEASE branch will be supported until November 20, 2010.  If you want stay on the the 8 branch (RELENG-8) you will have least until July 31, 2012; if there are any update releases in that branch then you will have until at least two years past the release date of the point release  See the links given by Stefan Lasiewski.Updating is as easy as following the instructions.