Browse Prior Art Database

Full Volume Migration

IP.com Disclosure Number: IPCOM000113624D
Original Publication Date: 1994-Sep-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 2 page(s) / 79K

Publishing Venue

IBM

Related People

Chow, WW: AUTHOR [+3]

Abstract

This invention is useful for management of data in storage hierarchies regardless of platform (MVS*, VM, AIX*, etc). Data is kept in hierarchies of storage devices to optimize cost and performance. For example a hierarchy may consist of level 1 is disk, level 2 is a tape library, level 3 is tape on the shelf onsite, level 4 is tape stored offsite. As the data ages, the performance and cost requirements may change and thus there is a need to migrate the data to a different service level. Also data may need to be exported to another system and placed in another storage hierarchy to move a user to another system or for load balancing.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Full Volume Migration

      This invention is useful for management of data in storage
hierarchies regardless of platform (MVS*, VM, AIX*, etc).  Data is
kept in hierarchies of storage devices to optimize cost and
performance.  For example a hierarchy may consist of level 1 is disk,
level 2 is a tape library, level 3 is tape on the shelf onsite, level
4 is tape stored offsite.  As the data ages, the performance and cost
requirements may change and thus there is a need to migrate the data
to a different service level.  Also data may need to be exported to
another system and placed in another storage hierarchy to move a user
to another system or for load balancing.

      Data movement for migration or export is expensive because it
uses system resources:  CPU, memory, channel use, communications
overhead, and tape mounts.  The old method for data movement is by
reading and writing files from one storage media to another.  This
new method for data movement is by physically moving the tape
cartridges that contains the files.  No tape mounts or tape
read/write is needed.  After the move, the files on the cartridge
have the service and performance of the new level in the hierarchy.

      The system can be planned to create the opportunity for moving
media rather than copying files or in some cases, the criteria for
data movement is not known ahead of time.  There are strategies to
retroactively recognize this potential opportunity.  To implement the
invention, there are several aspects:  (1) the format of the data on
the tapes cartridges must be compatible between storage repositories
on different platforms, (2) planning and strategies are needed to
create these situations where all the files on a cartridge meet the
criteria for such a data movement.  (3) code must be written to
recognize the opportunity to move cartridges through the hierarchy
and it must also perform the needed updates to reflect the new
storage locations.

      The most obvious example of this method is full volume
expiration.  Only data with the same expiration date is written on a
physical volume f...