There is only one file type that uses the .UFS extension:
FreeBSD Unix File System File
Unix file system file created for PC-BSD, a Unix operating system based on FreeBSD; stores the entire disk or a portion of a disk, including files, directories, and the file system structure; used to clone file systems for PC-BSD network installations.
UFS files may be compressed into .UZIP files that use the multiple file extension .UFS.UZIP.
Updated: June 7, 2010