define more partitions in freebsd

[s m]

hello all

i want to install freebsd8.2 on my system. for some reasons, i need
partitions more than 6. my freebsd just allow me to define partitions
from a to h, not any more.

i checked FreeBSD handbook, but it doesn't say anything about defining
more partitions.

my question is: how can i define more partitions on my freebsd? (for
example, ad3s1a, ..., ad3s1h, ad3s1i, ad3s1j, ...).

any comments or hints are appreciated.
SAM