UFS Resize UFS partition

Hi guys,

I'm running on an FreeBSD 10.1 RELEASE System. I have the following partitions:
gpart show
=>  34  654311357  vtbd0  GPT  (312G)
  34  1024  1  freebsd-boot  (512K)
  1058  645921792  2  freebsd-ufs  (308G)
  645922850  8388540  3  freebsd-swap  (4.0G)
  654311390  1  - free -  (512B)

My question is, is there the possibility to resize (in this case to downsize) the UFS partition with 308G without losing data?
I need some unpartitioned space (free space) for copy-on-write snapshots of my vserver.
Unfortunately I haven’t found a method for this by searching the web :(

Best wishes
Downsizing an active partition is not going to work, making it bigger is usually not a problem. In your case you'd have to backup the data, delete the existing partition, create a new (smaller) one and restore the data.