dontuse Profile Keyword

dontuse disk_name ...

By default, JumpStart uses all the operational disks on the system when partitioning default is specified. dontuse designates one or more disks that you don't want JumpStart to use. disk_name must be specified in the form cxtydz or cydz, for example, c0t0d0.

You cannot specify the dontuse keyword and the usedisk keyword in the same profile.