Do I need to reserve disk space for UFS snapshots?

[Kent Ho]

Hi,

I'm planing to use FreeBSD snapshots.  It seems to be the snapshop image 
is placed on the same file system.  The question is how do I manage or 
reserve space for the snapshots?  Can someone give me some guidelines or 
pointers.

Here's my netapp it has a separate area allocated for the snapshots, I'm 
keeping 2 weekly snapshots in there(weekly.0 & weekly.1) using around 30G.

Filesystem          kbytes       used      avail capacity  Mounted on
/vol/vol0/          305052552  272495320   32557232    89% /vol/vol0/
/vol/vol0/.snapshot  76263136   30658028   45605108    40% 
/vol/vol0/.snapshot

Filesystem               iused      ifree  %iused  Mounted on
/vol/vol0/            10802387   89822586    11%   /vol/vol0/

If copy all content in vol0 to a FreeBSD and make 2 snapshot will it be 
around the same? 272G + 30G = 302G?  So if I df on the FreeBSD box 
around 302G will be used?

Any help and information is highly appreciated.

Many thanks.

Kent.