You need only one file to recover pfSense:
[2.3.2-RELEASE][root@zzz]/root: cat /cf/conf/config.xml
Copy it to USB drive with DOS partition table, FAT32 file system, to directory named ‘conf’ in the main directory. For example:
scp root@zzz:/cf/conf/config.xml /media/usbstick/conf/
Plug the pen-drive into your server and start installation of pfSense from other media (cd, usb). The configuration file will be loaded automatically during the process. You don’t have to recover xml file etc. After the installation unplug the pen-drive (do not unplug it before reboot after installation).