A valid daemon database entry. See also soft-deleted database entry and hard-deletion of database entries .

The media onto which migrated data blocks are stored, usually tapes.

The combination of utilities that allows DMF to maintain a specified level of free space on a file system through automatic file migration.

The configuration object that defines path name and file size parameters necessary for DMF operation.

See bfid.

The bit file identifier, or bfid, is a unique identifier, assigned to each file during the migration process, that links a migrated file to its data on alternate media.

The collection of database entries and the user file associated with a particular bfid.

The sum of the states of the components that comprise a bfid set: the file state of any user file and the state of any database entries (incomplete, complete, soft-deleted, or active).

Physical unit of I/O to and from media, usually tape. The size of a block is determined by the type of device being written. A tape block is accompanied by a header identifying the chunk number, zone number, and its position within the chunk.

A list that contains an entry for each file in a file system eligible for migration, ordered from largest file weight (first to be migrated) to smallest. This list is generated and used internally by dmfsmon(8). The dmscanfs(8) command prints similar file status information to standard output.

The catalog (CAT) records in the tape MSP database that track which migrated files reside on which tape volumes.

That portion of a user file that fits on the current media (tape) volume. Most small files are written as single chunks. When a migrated file cannot fit onto a single volume, the file is split into chunks.

An entry in the daemon database whose path field contains a key returned by its MSP, indicating that the MSP maintains a valid copy of the user file.

The mechanism provided by the tape MSP for copying active data from volumes that contain largely obsolete data to volumes that contain mostly active data. This process is also known as volume merging or tape merging.

A series of parameter definitions in the DMF configuration file that controls the way DMF operates. By changing the parameters associated with objects, you can modify the behavior of DMF.

A string in the DMF configuration file that defines a part of a configuration object. By changing the values associated with these parameters, you can modify the behavior of DMF. The parameter serves as the name of the line. Some parameters are reserved words, some are supplied by the site.

A database maintained by the DMF daemon. This database contains such information as the bfid, the MSP name, and MSP key for each copy of a migrated file.

The configuration object that defines parameters necessary for dmdaemon(8) operation.

The portion of the inode that points to the file's data blocks.

The configuration objects that define parameters for DMF's use of tape devices.

An IBM disk drive.

See file state.

A file whose data resides both online and offline.

Those file systems that have the necessary inode space to support dual-state files.

See file handle.

An inode and its associated data blocks; an empty file has an inode but no data blocks.

The DMAPI identification for a file. You can use the dmscanfs(8), dmattr(1), and dmfind(1) commands to find file handles.

The migration state of a file as indicated by the dmattr(1) command. A file can be regular (not migrated), migrating, dual-state, offline, unmigrating, never-migrated, or have an invalid DMF state.

A user file that has been migrated and whose data blocks have been released.

A bfid-set state that consists of an offline user file and one or more active, complete MSP database entries.

A file that has one or more complete offline copies and no pending or incomplete offline copies.

A bfid-set state that consists of one or more active complete MSP database entries, no incomplete database entries, and either a migrated user file or an offline user file.

The administrative action that removes an MSP database entry from the daemon database and discards the MSP copy. See also active database entry and soft-deleted database entry.

The portion of a file that contains the bfid, the state field, and the data pointers.

An entry in the daemon database for an MSP that has not finished copying the data, and therefore has not yet returned a key. The path field in the database entry is NULL.

A bfid-set state that consists of a migrating user file; one or more active, incomplete MSP database entries; and possibly one or more complete active MSP database entries.

A file that has begun the migration process, but for which one or more copies on alternate media have not yet been made.

The daemon-like process by which data blocks are copied onto alternate media, and which assigns keys to identify the location of the migrated data.

A file that has a bfid and whose offline copies (or copy) are completed. Migrated files can be dual-state or offline.

A file that has a bfid but whose offline copies (or copy) are in progress.

See media-specific process (MSP).

The daemon database entry for a file that contains the path or key that is used to inform a particular MSP where to locate the copy of the file's data.

The configuration objects that define parameters necessary for that MSP's operation. There is one MSP object for each MSP.

A file that does not have a bfid or any offline copies. See regular file.

A file whose inode contains a bfid but whose disk blocks have been removed. The file's data exists elsewhere in copies on alternate media.

In tape MSP processing, a character string that the MSP returns to the daemon to indicate how a file is to be retrieved. For the tape MSP, the offline pointer is the character key into the MSP catalog (CAT) records of the database.

Unused chunks in the tape MSP catalog (CAT) database entries resulting from the removal of migrated files.

Unused database entries resulting from the removal of migrated files during a period in which the DMF daemon is not running.

See configuration parameter.

The configuration objects that specify parameters to determine MSP selection, automated space management policies, and/or file weight calculations in automatic space management.

To request that a migrated file's data be moved back (unmigrated) onto the file system disk, either by explicitly entering the dmget(1) command or by executing another command that will open the file, such as the vi(1) command.

DMF considers a regular file to be one with no bfid and no offline copies.

The information about all bfid sets that is collected and analyzed by dmaudit(8). The snapshot analysis is available from the report function.

A daemon database entry for which the MSP copy of the data is no longer valid. Data remains on the alternate media until the database entry is hard-deleted. See also active database entry and hard-deletion of database entries.

A tape containing only a small amount of active information.

UNIX special files are never migrated by DMF.

The field in the inode that shows the current migration state of a file.

See block.

See chunk.

A file that the daemon will never select as a migration candidate.

See recall.

A special file created in the user file's file system by the DMF daemon when a file is recalled. The unmigration file holds the data pointers until the MSP process successfully copies the file's data back onto the file system disk from the alternate media; when the copy is complete, the daemon moves the data pointers from the unmigration file inode back into the user file's inode.

A directory in which unmigration files are stored.

A bfid-set state that consists of one or more soft-deleted daemon database entries, either incomplete or complete. There is no user file.

The process of removing the bfid from the user file inode and soft-deleting all associated database entries.

The volume (VOL) records in the tape MSP database that contain information about each tape volume that exists in the pool of tapes used by the tape MSP.

The mechanism provided by the tape MSP for copying active data from volumes that contain largely obsolete data to volumes that contain mostly active data.

A logical grouping of chunks. Zones are separated by file marks and are the smallest block-addressable unit on the tape volume. The target size of a zone is configurable by media type.