Want to reinstall, preserving existing configuration

[Michael B. Eichorn]

On Thu, 2015-12-10 at 17:04 -0800, David Benfell wrote:
> Quoting Charles Swiger <cswiger at mac.com>:
> 
> > On Dec 10, 2015, at 1:22 PM, David Benfell <benfell at parts-unknown.o
> > rg> wrote:
> > [ ... ]
> > > Because there's nothing else terribly wrong, I'd basically like
> > > to  
> > > preserve the existing configuration. That includes ports and
> > > the  
> > > build options. Has anyone come up with a neat procedure for
> > > doing  
> > > this?
> > 
> > Certainly: take a backup.
> 
> To me, this leaves some very important questions unanswered.
> 
> First, won't there be some differences in the configuration for UFS  
> versus ZFS?
> 
> Second, who has a sane backup method for a 500 GB disk that will
> put  
> all the boot stuff in all the right places on a restore?
> Particularly  
> when the bootloader is a different bootloader for UEFI on UFS than  
> Grub for ZFS?

I think he was refering to a non-block form of backup like rsync or
tarsnap. Because of FreeBSD's base/ports separation you can pretty much
snag /var, /etc, /usr/local, and /usr/home and drop them on a fresh
base and it should work fine. You would probably want to tweak rc.conf
to remove zfs_enable and make sure you transfer and changes you may
need in login.conf and loader.conf, but that is pretty much it.

(List: did I miss a directory here? It is late at night for me)

Since you mentioned port options you might want to grab /usr/ports too.
I am not so sure of this, List: please chime in here.

If you are looking for a comprehensive guide there are probably some
blog posts about using tarsnap or aws for backups, most people using
them are paying for space and transfer so they try to keep things tight
and rarely backup base.