Data Management attributes

Data Management attributes can be associated with any individual file. There are opaque and non-opaque attributes.

An opaque attribute has a unique name, and a byte string value which is not interpreted by the DMAPI implementation. Non-opaque attributes, such as managed regions and event lists, are used internally by the DMAPI implementation.

DM attributes are persistent. They are kept in a hidden file in the file system.

GPFS provides two quick access single-bit opaque DM attributes for each file, stored directly in the inode. These attributes are accessible through regular DMAPI functions, by specifying the reserved attribute names _GPFSQA1 and _GPFSQA2 (where _GPF is a reserved prefix). The attribute data must be a single byte with contents 0 or 1.