Currently, if the drives specified for volume creation are not active GEOM providers, it will result in a kernel panic.
Currently, if the drives specified for volume creation are
not active GEOM providers, it will result in a kernel panic.

If the GEOM provider or disk goes away before the volume
configuration data gets written to the disk, it will result
in another kernel panic.

o Make sure that the drives specified for volume creation
  are active GEOM providers.

o When writing out volume configuration data to associated drives,
  make sure that the GEOM provider is active, otherwise continue
  to the next drive in the volume.

Approved by:	le, bmilekic (mentor)

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