FreeBSD kernel update instructions are provided here.

For H-Sphere production servers, it is required to recompile FreeBSD kernel with quota enabled.

1. Under root, change to the /usr/src/sys/i386/conf directory where the kernel source is located: # cd /usr/src/sys/i386/conf
2. In this directory, you will have the default GENERIC kernel configuration file, and, if the custom kernel compilation has been performed, a custom kernel configuration file, MYKERNEL, for example.
3. Edit your current kernel configuration file (MYKERNEL, for example):
   # vi MYKERNEL
   and add the "options QUOTA" line there.
   Important: We highly recommend not to modify the default GENERIC file, but to copy its content to the custom file (like MYKERNEL) And to perform modifications there!
4. Generate the kernel source code by these commands:
   /usr/sbin/config MYKERNEL
   cd ../../compile/MYKERNEL
   make depend
   make
   make install
5. Reboot FreeBSD server to activate the new kernel settings.