tunefs -m minfree for "big drives"

[Thomas Vogt]

Hi

FreeBSD 4.9 man tunefs(8) explains in section "-m minfree" that default 
8% disk space is reserved for root. The man page also says clearly that 
I'll lose performance if I lower minfree.
On my mailserver I've one drive for the base system and a raid 
enviroment with 500GB space for the users mailboxes. 8% of 500gb space 
is a lot of space which I can't use anymore for my users mailboxes.
So if I set this minfree to < 8% is there any other option I've to set 
that I don't lose too much performance. We talk about a lot of write 
procedures for small files.

Regards
Thomas Vogt