provider name to be specified instead of geom name (first argument in all
subcommands except label). In most cases there is only one array used
any way, so it is not really useful to make user type ugly geom names like
Intel-f0bdf223 or SiI-732c2b9448cf. Though they can be used in some cases.
Sponsored by: iXsystems, Inc.
MFC after: 1 month