The method by which you place a disk under VxVM control depends on the following circumstances:
If the disk is not needed immediately, it can be initialized (but not added to a disk group) and reserved for future use. To do this, enter none when asked to name a disk group. Do not confuse this type of "spare disk" with a hot-relocation spare disk.
If the disk was previously in use by LVM, you can preserve existing data while still letting VxVM take control of the disk. This is accomplished using conversion. With conversion, the virtual layout of the data is fully converted to VxVM control.
If the disk was previously in use, but not under VxVM control, you may wish to preserve existing data on the disk while still letting VxVM take control of the disk. This can be accomplished using encapsulation.
It is possible to configure the vxdiskadm utility not to list certain disks or controllers as being available. For example, this may be useful in a SAN environment where disk enclosures are visible to a number of separate systems.