Hpss Files, Filesets, Volumes, Storage Segments And Related Metadata; Figure 2. Class Of Service / Hierarchy / Storage Class - IBM High Performance Storage System HPSS Installation Manual

2.3.1. HPSS Files, Filesets, Volumes, Storage Segments and Related
Metadata
The various metadata constructs used to describe the HPSS namespace and HPSS storage are
described below:
Files (Bitfiles)
•
Model terminology, are logical strings of bytes, even though a particular bitfile may have a
structure imposed by its owner. This unstructured view decouples HPSS from any particular
file management system that host clients of HPSS might use. HPSS bitfile size is limited to2
- 1 bytes.
Each bitfile is identified by a machine-generated name called a bitfile ID. It may also have a
human readable name. It is the job of the HPSS Core Server (discussed in Section 2.3.2) to
map a human readable name to a bitfile's ID.
.
Filesets A fileset is a logical collection of files that can be managed as a single administrative
•
unit, or more simply, a disjoint directory tree. A fileset has two identifiers: a human readable
name and a numeric fileset ID. Both identifiers are unique to a given realm.
.
Junctions A junction is a Core Server object, much like a symbolic link to a directory, that is
•
used to point to a fileset. This fileset may belong to the same Core Server or to a different
Core Server. When pointing to a different Core Server, junctions allow HPSS users to traverse
to different subsystems.
File Families. HPSS files can be grouped into families. All files in a given family are
•
recorded on a set of tapes assigned to the family. Only files from the given family are
HPSS Installation Guide
Release 6.2 (Revision 2.0)

Figure 2. Class of Service / Hierarchy / Storage Class

.
Files in HPSS, called bitfiles in deference to IEEE Mass Storage Reference
July 2008
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