FreeNAS 8.x is a complete different software compared to 0.7. There is a
complete feature parity between 0.7 (legacy) and 8.x with plugins, there
are also some features in 8.x that aren't available in 0.7.
There isn't an upgrade path from 0.7 to 8.x.

To build the system (experts only):

Requirements:

- Your build environment must be FreeBSD 8.1-RELEASE or newer.
- amd64 or i386 for i386 builds; an amd64 for amd64 builds.
- You will need the following ports/packages when compiling anything
  FreeNAS-related:
  - devel/git-subversion
  - lang/python26 or lang/python27

- You need the following additional ports/packages to build the FreeNAS base
  OS image:
  - sysutils/cdrtools

- You need the following additional ports/packages to build the plugins jail:
  - ports-mgmt/pbi-manager

- The port security/sudo is recommended but not required, if you do not have
  the port installed you can run the commands listed in this doc as root.

Building the System Quickstart Flow:

- Checking out the code from git:
/** this clone command checks out just the stable/8.3 branch **/
/** Reference -> http://stackoverflow.com/questions/4811434/git-clone-only-one-branch **/

% git clone -b stable/8.3 --single-branch git://github.com/gpanula/freenas.git freenas-8.3
% cd freenas

- Use the build script

% sudo sh build/do_build.sh

This will fetch TrueOS and ports for the build. However it is recommended that you maintain a local git mirror to speed up further builds:

% git clone git://github.com/freenas/ports.git ${HOME}/ports
% git clone git://github.com/trueos/trueos.git ${HOME}/trueos

To build using those local mirrors run:

% sudo env GIT_REPO=${HOME}/trueos GIT_PORTS_REPO=${HOME}/ports sh build/do_build.sh

That's it.

The End Result:

If your build completes successfully, you'll have an image in
obj.yyyy/FreeNAS-VVVV-XXXX-yyyy.img.xz where:

- VVVV is the 'release' branch version or.
- XXXX is the git commit hash from the FreeNAS repo.
- yyyy is either i386 or amd64 depending on your platform and what was
  provided via $FREENAS_ARCH on the command line / via the environment.

This is a compressed raw disk image, and needs to be decompressed and
converted to your favorite VM container format before use, flashed on to a USB
key fob, etc.  There will also be a CD/DVD image,
obj.yyyy/FreeNAS-VVVV-XXXX-yyyy.iso, that you can use to install/upgrade
FreeNAS.

Common workflows:

1. Building an i386 on an amd64 build server:

% sudo env FREENAS_ARCH=i386 sh build/do_build.sh

2. Forcing an source / ports update:

% sudo sh build/do_build.sh -u

3. Updating ports patches:

% sudo rm -Rf os-base/$FREENAS_ARCH/ports/packages/
% sudo sh build/do_build.sh -u

NOTE: when things get smarter (and they will.. the developers feel your pain
too :/..), nuking individual packages won't be required; this will require
fiddling around with the ports infrastructure, which is a semi-large
undertaking. Thus, I wouldn't expect this to be enhanced anytime soon :(..
(but it's annoyed the author of this document enough that it's time to fix
things properly!).

4. Update source and ports, patch, and rebuild FreeBSD:

% sudo sh build/do_build.sh -fu

5. Force a build from scratch (nukes packages, rebuild FreeBSD):

% sudo sh build/do_build.sh -ff

6. Build everything required (src, ports) but don't produce GUI upgrade/CD
   images:

% sudo sh build/do_build.sh -- -i

Submitting Build Bugs:

Please execute the 'build/build_bug.sh' command and follow the directions
described by the script.