- If RB_ASKNAME, prompt for the dump device, defaulting to
partition 'b' of the root device, if the root device is a disk.
- Else, if dumpspec is set to "none", do not configure a dump device.
- Else, if dumpspec is set by config(8), attempt to use that device.
- Else, dumpspec is wildcarded or unspecified; if the root device is
a disk, select partition b. (which was the previous default dump
partition)
Note, dumps to a local disk now work even if root is on nfs.