Can sysinstall be run interactively to install onto a second drive?

[Peter Steele]

Can I run sysinstall on a live system, booted say from ad0 and use it to install a new OS onto a second drive, say ad1? I'm trying to do something like this: 

sysinstall configFile=install.cfg loadConfig 

where I have the target drive identified in the sysinstall script, but it doesn't seem to like what I'm trying to do. 

Basically what I need to do is given a FreeBSD distribution, I want an automated procedure I can run on a system to build a new system with a specific set of packages and other customizations we need. We have this setup now using a PXE boot server, but I'd like something I can run interactively that doesn't require a boot server.