Unisys Corporation

Donald Ralph Hart

Kung Yi Lin

Alma Navarro De Jesus

Shawmo Edmund Lin

Patricia Jean Shapiro

Courtney Chi Hoang

Anagha Rajpurkar

Shirley Jean Ritsch

Anagha Raipurkar

Patricia Jean Keller

Methods and systems are disclosed to perform dynamic disk data redistribution in a database environment. The methods and systems disclosed herein provide for the transparent redistribution of data across multiple physical disks of a database while maintaining accessibility to the database. Methods and systems are also disclosed for handling requests to perform database operations on data that is in the process of being redistributed.

Dynamic disk redistribution

In order to overcome limitations of network connections between a primary host server and a remote secondary host server, the audit file of a primary database is mirrored to an audit file of the remote secondary backup database. A special sensing program called TRACKER operates to speed up the synchronization (duplication) between the primary database and secondary remote database.

Method for reading audit data from a remote mirrored disk for application to remote database backup copy

A method for creating multiple QUIESCE DATABASE Copies (QDC) on a single server by mirroring a disk copy of a live database that is in a quiesced state and splitting them from their source, and then bringing the mirrored disks containing online snapshots back online to the server.

System and method for creating multiple QUIESCE database copies at a single server

A method is provided to automatically select the correct order of backups from selected DUMP files in order to recover and rebuild a complete database in reduced time without requiring the user to search, find and select the correct order of items for the backup.

Method for reducing database recovery time

A method is provided to verify a database copy of a primary database which has been replicated. A secondary physically consistent copy of the primary database is put in a state of quiesce while the primary database is allowed to resume update activity. The consistent copy, in a state of quiesce, can be used for database maintenance activities or as a recovery source should the primary database be damaged, but the consistent copy is first checked for integrity by using a Verify option before such recovery source is utilized.

System and method for verification of a quiesced database copy

In a network of primary and secondary servers having individual databases which are mirrored to each other, there is provided a method to increase resource availability by removal, of already-utilized audit files onto external storage. A TRACKER program for expediting the update of the secondary database will initiate a CopyAudit program which offloads the audit files on the secondary server and then signals the primary server to offload the audit file, of the primary, onto external storage.

System and method for automatic audit data archiving within a remote database backup system

A rapid database recovery program uses an auxiliary database means (D) mirrored to replicate a primary active database means (D). A utility and recovery program utilizes the primary audit file (A) to update the auxiliary database (D) to make it immediately available for transaction operations.

System and method for database recovery using a mirrored snapshot of an online database

An online primary database is automatically configured to enable a physically consistent snapshot of the primary database at the secondary database to be uniquely mirrored to a secondary remote database as backup while allowing the specialized control audit images to be created at the primary database.

Method for capturing a physically consistent mirrored snapshot of an online database from a remote database backup system

An on-line primary database is momentarily QUIESCED to enable a physically consistent snapshot of the primary database to be mirrored to a secondary database as a backup while allowing the primary database to continue on servicing multiple user applications.

Method of capturing a physically consistent mirrored snapshot of an online database

A method for sensing and regulating the level of synchronization between a file of audit blocks generated in a primary host for transfer to a secondary host. The audit files in a primary host are divided into audit blocks which are each identified with an audit block serial number. The individual audit blocks are transmitted through a network from a primary host to a secondary host wherein a tracker mechanism monitors the difference between the number of received audit blocks and the number of generated audit blocks residing at the primary host waiting to be transferred. When the disparity between the audit blocks received and the generated audit blocks waiting to be transmitted reaches a certain critical level, the tracker mechanism will initiate an advance speed up program to expedite the transfer in order to bring the primary and secondary audit files into greater synchronism. Further, the acknowledgment level can be set to indicate the number of audit blocks received in the secondary host for information back to the primary host and the acknowledgment level can be utilized in order to preset a critical value which will indicate that the speed up transfer operation should be initiated.

Tracker sensing method for regulating synchronization of audit files between primary and secondary hosts

In order to obviate data discrepancy between a primary source database and a secondary remote backup database, a Tracker program is used to sense the lack of synchronism between a primary audit file and secondary audit file. Then, a Catch-up program operates to transfer sectioned audit files from the primary to secondary in a parallel transfer mode until the primary and secondary audit files are accurate duplicates of each other, i.e., they are now in synchronism.

System and method for asynchronously receiving multiple packets of audit data from a source databased host in a resynchronization mode and asynchronously writing the data to a target host

In order to correlate or synchronize the database of a source primary host with the backup database of a remote secondary host, the present method operates to speed up the transfer of audit blocks from primary host to secondary host when an out-of-sync signal indicates the secondary host audit blocks are not on a par with the primary host audit blocks. A Catchup process utilizes multiple buffers of audit blocks at the primary host which can then be asynchronously transferred, by a sequence of Catchup tasks, on a parallel concurrent operation, over to physical files of said secondary host.

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Irvine, CA, United States of America

Donald Ralph Hart