VxFS utilizes two types of volumes, one of which contains only data, referred to as dataonly, and the other of which can contain metadata or data, referred to as metadataok.
Data refers to direct extents, which contain user data, of regular files and named data streams in a file system.
Metadata refers to all data allocated when the file system was created with the mkfs command or allocated at a later time. Metadata includes extents allocated to structural files, blocks reserved for the super block, the volume label, indirect extents, extents belonging to the File Change Log file, the history log file, extended attributes, directories, access control lists, and so on.
A volume availability flag is set to specify if a volume is dataonly or metadataok. The volume availability flag can be set, cleared, and listed with the fsvoladm command.
fsvoladm(1M) manual page.