VERITAS Volume Manager 4.1 Administrator's Guide

Chapter 4 171
If you do not specify the base of the minor number range for a disk group,
VxVM chooses one at random. The number chosen is at least 1000, is a
multiple of 1000, and yields a usable range of 1000 device numbers. The
chosen number also does not overlap within a range of 1000 of any
currently imported disk groups, and it does not overlap any currently
allocated volume device numbers.
NOTE The default policy ensures that a small number of disk groups can be
merged successfully between a set of machines. However, where disk
groups are merged automatically using failover mechanisms, select
ranges that avoid overlap.
For further information on minor number reservation, see the vxdg(1M)
manual page.