You can use the vxassist make command to create a volume for site-based allocation.

vxassist [-b] [-o notrackalign] -g<DynamicDiskGroupName> make [<VolumeName>] <length>[type={mirror|raid5|stripe}[,log]] [<alloc_attributes...>] [Column=N] [StripeUnit=<width>] [Site=<sitename1>[,<sitename2>,...]] [DriveLetter={A|B|..|Z}|DrivePath=<DrivePath>] [<[!]diskname | p#c#t#l#> ...]

See vxassist make.

For example run the following command:

vxassist -g testdg make testvol1 100M Site=s1

The above command creates a Site Confined volume (testvol1) on disks belonging to site (s1)

For example, run the following command:

vxassist -g testdg make testvol1 100M type=mirror mirror=3 Site=s1

The above command creates a Site Confined volume (testvol1) with all three plexes residing on disks belonging to site (s1.)

For example, run the following command:

vxassist -g testdg make testvol1 100M type=mirror mirror=3 Site=s1,s2,s3

The above command creates a Site Separated volume (testvol1) with each of the three plexes residing on disks belonging to sites (s1, s2, and s3) respectively.