Browse Prior Art Database

Migrated Data Backup Utility

IP.com Disclosure Number: IPCOM000112967D
Original Publication Date: 1994-Jun-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 4 page(s) / 108K

Publishing Venue

IBM

Related People

Mitton, KG: AUTHOR [+2]

Abstract

Space management includes the migration of seldomly referenced data to lower cost storage media. The introduction of space management functions to some operating environments may introduce incompatibilities with many backup products. The incompatibilities arise because a migrated file no longer is self contained but rather consists of catalog information in primary storage and associated migrated data located elsewhere (in a lower cost storage repository). Disclosed is a design which allows the protection of migrated files in environments where existing backup products do not provide this support.

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

Migrated Data Backup Utility

      Space management includes the migration of seldomly referenced
data to lower cost storage media.  The introduction of space
management functions to some operating environments may introduce
incompatibilities with many backup products.  The incompatibilities
arise because a migrated file no longer is self contained but rather
consists of catalog information in primary storage and associated
migrated data located elsewhere (in a lower cost storage repository).
Disclosed is a design which allows the protection of migrated files
in environments where existing backup products do not provide this
support.

      Data Facility Storage Management Subsystem/Virtual Machine
Function Level 220 (DFSMS/VM* FL220) and FL221 are features of the
Virtual Machine/Enterprise Systems Architecture (VM/ESA*) operating
system.

      DFSMS/VM FL220 and FL221 provide space management for VM Shared
File System (SFS) files.  This space management includes the
migration of SFS files to Migration Level 1 (ML1) and ML2 storage.
Migration processing moves the file data to lower cost secondary (ML1
or ML2) storage while leaving an empty file in primary storage.
Installa- ations using this space management function must be able to
protect the files which have been migrated.  This same scenario may
replay itself as space management functions are introduced to other
operating environments (e.g., UNIX** platforms).

      The backup (or recovery) of primary files must be synchronized
with the backup (or recovery) of their associated migrated data in
order for the files to be recallable.  The disclosed design provides
locking means that allow various levels of locking of primary and
migration level storage in order to provide this synchronization.

      The disclosed design further provides means for the saving of
primary file attributes for each migrated file during backup using
any backup product.  These primary file attributes, along with
information correlating the primary files with their associated
migrated data in migration storage, are saved in a table.  This
correlation table is saved in secondary storage and is backed up
along with the migrated data.

      Finally, the disclosed design provides a means of recreating
files in the migrated state.

      An embodiment of this disclosure requires some unique
identifier in the primary file system which can be used to represent
the migrated data.  If such identifier exists in the primary file
system, or can be created, this can be used to correlate a primary
file with a file containing its migrated data.  This correlation must
be saved for each migrated file (in addition to the file's catalog
data) in order to be able to restore those files.

      The preferred embodiment uses the VM Shared File System's
(SFS's) internal unique object identifier as the basis for
referencing migrated files.  Another embodiment (for the UNIX world)
...