HIERARCHICAL STORAGE MANAGEMENT
multi-function drive is a
single drive unit. It is capable of reading and writing a variety of disk
media. Three types of technologies are used for multi-function drives. They
are:
(i)
Magneto-optical disk for both rewritable and WORM capability.
(ii)
Magneto-optical disk for rewritable and dye polymer disk for WORM
capability.
(iii)
Phase change technology for both rewritable and WORM capability.
The storage hierarchies
described in thE pyramid consist of random access memory (RAM), on-line fast
magnetic hard disks, optical disks and juke boxes, diskettes, and tapes.
Permanent Vs. Transient Storage issues
The process of moving an
object from one level in the storage hierarchy to another level in that
hierarchy is called migration. Migration to objects to off-line media and
removal of these objects from on-line media is called archiving. Migration Can
be set up to be manual or automatic.
Manual migration requires the
user or the system administrator to move objects from one level of storage to
another level. Systems with automatic migration perform this task
automatically. In document-imaging systems, compressed image files are created
in magnetic cache areas on fast storage devices when documents are scanned.
Optical Disk Library (Juke box)
An optical juke box stacks
disk platters to be played. In the optical disk library, the platters are
optical and contain objects such as data, audio, video, and images.
An optical disk library has
one or more optical drives. An optical disk library uses a very-high-speed and accurate
server-controlled electromechanical robotics elevator mechanism for moving the
optical platters between their slots on a disk stacks and the drives. The
robotics mechanism removes disk platter from a drive and returns it to its
slots on the stack after the disk has finished playing (usually when the drive
is required for another disk). The robotics device operates and manages
multiple drives under program control. .
A juke box may contain drives
of different types, including WORM, rewritable, or multifunction. Juke boxes
contain one or more drives. A juke box is used for storing large volumes of
multimedia information in one cost effective store.
Juke box-based optical disk
libraries can be networked so that multiple users can access the information.
Optical disk libraries serve as near-line storage for infrequently used data.
Hierarchical Storage Applications: Banks, insurance companies, hosptials, state
and federal governments,
manufacturing companies and a variety of other business and service organizations
need to permanently store large volumes of their records, from simple documents
to video information, for audit trail use.
Related Topics
Privacy Policy, Terms and Conditions, DMCA Policy and Compliant
Copyright © 2018-2026 BrainKart.com; All Rights Reserved. Developed by Therithal info, Chennai.