Replication system and method
AssigneeNEC Corporation
InventorsJunichi Yamato, Masaki Kan
Life of this patent
Estimating the term…
Abstract
After a backup of master storage is created, a difference map corresponding to the backup is created. Updates made by a host after creating the backup are recorded in the difference map in the master storage. Backup data is restored to replica storage. A pair of the master storage and the replica storage is created. Data in update locations, generated after creating the backup of the master storage, is transferred to the replica storage based on the difference map to update data in the replica storage and the replica storage is synchronized with the master storage for replication.
Claims20
A replication method comprising:
- creating, by a replication source system, a backup of a storage of said replication source system;
- recording, by a replication source system, an update made to the storage of said replication source system, after creating said backup, as difference information;
- restoring, by a replication destination system, a storage of said replication destination system from a backup medium sent from said replication source system;
- and
- transferring update information as to the update made to the storage of said replication source system after creating said backup, from said replication source system to said replication destination system.
A replication system including a replication source system and a replication destination system connected to said replication source system via a communication line;
- said replication source system comprising:
- a backup device to which a backup of a storage of the replication source system is stored;
- a difference map in which an update made to the storage of the replication source after creating the backup of the storage of the replication source, is recorded as difference information;
- and
- means for transferring update information as to the update made to the storage of the replication source after creating the backup, to said replication destination system based on the difference map;
- said replication destination system comprising:
- a backup device for reading backup data from a backup medium in which the backup data is stored from said backup device of said replication source system;
- means for restoring the backup data of said backup medium into a storage of the replication destination;
- and
- means for receiving the update information, transferred from said replication source system to update the storage of the replication destination system.
A pairing processing apparatus, connected to a replication source and to a replication destination which is connected to said replication source via a communication line, said apparatus comprising:
- means for controlling replication pairing according to a replication pair creation mode pre-set for the replication source and the replication destination;
- and
- estimation means for estimating a first time and a second time and for determining a selection of either restoration of a backup and transfer of difference information or transfer of entire data of the replication source via the communication line, according to estimation results of the first time and the second time, when the replication pair creation mode is a use-backup mode, said first time being a time required for establishing synchronization by the restoration of a storage at the replication destination using backup data backed up from storage of the replication source and the transfer of the difference information, generated after creating the backup at the replication source, from the replication source to the replication destination via the communication line;
- said second time being a time required for establishing synchronization by the transfer of entire data of the storage of the replication source via the communication line between the replication source and the replication destination.
Dependencies are inferred from the claim text.