This glossary defines some of the terms and acronyms used in the AdvFS documentation.
A layered product available by license. The utilities allow you to create and manipulate multivolume domains.
The agent that issues commands and obtains system information for the AdvFS GUI.
The agent runs in the traditional style of the UNIX daemon.
See also advfsd
The time interval between agent scans of the system disk.
A nonblocking I/O scheme where data is written to the cache and might return control before the data is written to the disk.
Guarantees that all data in a write system call (up to 8 KB) is either written to the disk or none of the data is written to the disk.
To even the distribution of files between volumes of a domain.
A set of pages that AdvFS views as one entity. Reserved files and user files are bitfiles.
See BMT
A 512-byte unit of disk storage. Sixteen blocks comprise a page.
Bitfile metadata table. An array pages, each with a header and an array of mcells located on each volume. A BMT contains metadata, including file attributes, file extent maps, fileset attributes, and the POSIX file statistics, for all files that have storage on the volume.
The area of memory that contains the blocks of data read from and/or waiting to be written to disk.
Blocks created during tape backup for error recovery.
See fileset clone
A real-time performance monitoring application.
Storage that is physically adjacent on a disk volume.
The process by which original information is saved in an AdvFS fileset clone when data in the original file is changed.
To make each file and free space in a domain more contiguous.
An I/O scheme that synchronously reads and writes data from a file without copying it to a cache.
Data that has been written by the application, but the file system has cached it in memory so it has not yet been written to disk.
A named pool of storage that contains one or more volumes. Sometimes referred to as file domain.
A set of numbers that identify the domain to the system.
A condition that prevents further access to the domain when corruption in the domain is detected. AdvFS allows the filesets in the domain to be unmounted after a domain panic.
See DVN
Domain version number. A number in the disk metadata that specifies file structure. Domains created with the operating system software Version 5.0 and later contain a DVN of 4, while domains created under earlier versions of the operating system have a DVN of 3.
The AdvFS Graphical User Interface (GUI).
A directory that contains the domain definitions.
A file that identifies file systems that are to be mounted at system reboot.
Contiguous area of disk space allocated to a file. A file might have zero or more extents.
A table of the size and location of the extents belonging to a file. Simple files have one extent map; striped files have an extent map for every stripe segment.
See extent
Created when a file uses only part of the last page of file storage allocated or has a total size of less than 8 KB.
A hierarchy of directory and files. A fileset represents a mountable portion of the directory hierarchy of the AdvFS file system.
A read-only copy of a fileset that preserves the data and structure of an existing fileset at the time the clone is created. Initially the clone uses very little space. The first time data in a block assigned to the original fileset changes, the original block is preserved in the clone. As more disk blocks change, the clone uses more disk space. The contents of the AdvFS fileset clone can be backed up while the original fileset remains available to users.
A unique identifier that associates the fileset with its domain.
A quota that limits the amount of disk storage that a fileset can consume or the number of files a fileset can contain.
A file that is used to allocate storage for files or file segments that are less than 8 KB (one page). Using fragments reduces the amount of wasted disk space.
The period of time a quota's soft limit can be exceeded as long as the hard limit is not exceeded.
The time interval between updates of the GUI window information.
The quota limit for disk block usage or number of files that cannot be exceeded.
A numeric file identifier.
Logical Storage Manager. LSM is a storage management system that provides data redundancy and volume-level striping.
See LSM
Metadata cells that contain records of file statistics.
File structure information such as file attributes, extent maps, and fileset attributes.
To move files from one volume to another within a domain.
(v.) To maintain identical copies of data on different storage areas. (n.) One of the copies that is maintained.
Maps areas of the volume that do not represent AdvFS metadata, such as the disk label and boot blocks.
NetWorker for Tru64 UNIX provides scheduled, online automated backup.
A volume, domain, fileset, or fileset clone managed by the AdvFS GUI.
The AdvFS GUI hierarchical display of objects.
An allocation of 8 KB of contiguous disk space (16 blocks).
Product authorization key. License to access Compaq Computer Corporation software.
See PAK
A file that stores quota limits and keeps track of number of files, disk block usage, and grace period per user ID or per group ID. Fileset quota information is stored within the fileset metadata.
A bitfile that defines the location of all filesets in a domain. Each domain has one.
A collection of blocks created by the
vdump
utility to save AdvFS backup information.
See stripe segment
The quota value beyond which disk block usage or number of files is allowed only during the grace period.
A file whose pages do not all have allocated disk space.
See volume
Keeps track of allocated disk space on a volume.
To distribute data across multiple storage areas. AdvFS stripes individual files. LSM and hardware RAID stripe all files.
For AdvFS, the portion of a striped file that resides on a volume. A file striped across four volumes has four stripe segments. Segments can be migrated from one volume to another.
A unique identifier for an AdvFS file within a fileset.
The log file that records changes to metadata before the changes are written to disk. At regular intervals these changes are written to disk.
A directory that contains the most recently deleted files from an attached directory. Trashcan directories can be set up by each user for user files.
Unified Buffer Cache. The dynamically allocated system buffer cache that holds file data and AdvFS metadata.
See UBC
For AdvFS, anything that behaves like a UNIX block device. This can be a disk, disk partition, or logical volume.
The process by which the modifications to the file-structure information are completely written to a transaction log file before the actual changes are written to disk.