Well, he also has a choice of just leaving them alone.
Depends on what you want exactly. Some organizations like having all disks under VxVM, so there you'd want to encapsulate. That also lets you mirror your root with VxVM.
However you can leave it alone and with version 4.0 or higher, VxVM won't care. They'll just show up in 'vxdisk list' as unconfigured disks all the time. You can do that if you prefer to mirror them with SVM.
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Darren