OpenBSD webserver partitioning schemes

[Bray Mailloux]

I'm not too knowledgeable in the security arena so this question may 
prompt flogging.

My server has three hard drives, one contains the OpenBSD system and the 
other two are blank and will be a raid mirror of the /var/www directory. 
Is it wise to give over the entire drive for the mount point /var/www or 
should I not be assigning mount points to entire drives?