Synchronization and resynchronization of loosely-coupled copy operations between a primary and a remote secondary DASD volume under concurrent updating
First Claim
1. A method for copying data from a first storage system to a second storage system, comprising:
- copying data from storage locations in the first storage system to the second storage system;
detecting update data to one storage location in the first storage system while copying data from storage locations in the first storage system to the second storage system;
storing the update data to the first storage system;
transmitting the detected update data to the second storage system; and
applying the update data to the second storage system in a manner that maintains consistency between data copied from the storage locations and update data, wherein the update data is transmitted to the second storage system before all the data as been copied from the storage locations in the first storage system to the second storage system, and wherein the update data is capable of being applied to the second storage system while copying data from the storage locations in the first storage system to the second storage system.
0 Assignments
0 Petitions
Accused Products
Abstract
A method for assuring consistency between a primary volume and a remote secondary volume wherein a host CPU manages track-to-track transfers using loosely-coupled, storage control unit mediated, data paths. The method includes initial volume synchronization in which concurrent updates to primary tracks are serialized by the copy progression at the secondary volume according to address. The method further includes volume resynchronization in the event of extrinsic error, fault, or the like in which the status of primary tracks updated during a volume suspension interval utilize bit maps to determine status of tracks unmodified during the suspension interval, and updated tracks and timestamps in addition to addresses. The bit maps and timestamps preserve the most recent version copy order of the tracks on the secondary volume.
-
Citations
30 Claims
-
1. A method for copying data from a first storage system to a second storage system, comprising:
-
copying data from storage locations in the first storage system to the second storage system;
detecting update data to one storage location in the first storage system while copying data from storage locations in the first storage system to the second storage system;
storing the update data to the first storage system;
transmitting the detected update data to the second storage system; and
applying the update data to the second storage system in a manner that maintains consistency between data copied from the storage locations and update data, wherein the update data is transmitted to the second storage system before all the data as been copied from the storage locations in the first storage system to the second storage system, and wherein the update data is capable of being applied to the second storage system while copying data from the storage locations in the first storage system to the second storage system. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
-
8. A method for copying data from a first storage system to a second storage system, comprising:
-
copying update data to the first storage system to the second storage system;
suspending the copying of update data from the first storage system to the second storage system;
indicating in an update data structure all storage locations in the first storage system that received updates before and during the suspension of the copying; and
after ending the suspension;
(i) copying data from storage locations in the first storage system indicated in the update data structure to the second storage system;
(ii) transferring update data received after the suspension to storage locations in the first storage system to the second storage system; and
(iii) applying the update data to the second storage system in a manner that maintains consistency between data copied from the storage locations that is indicated in the update data structure and update data received after the suspension. - View Dependent Claims (9, 10)
-
-
11. A system for copying data, comprising:
-
a first storage system;
a second storage system;
means for copying data from storage locations in the first storage system to the second storage system;
means for detecting update data to one storage location in the first storage system while copying data from storage locations in the first storage system to the second storage system;
means for storing the update data to the first storage system;
means for transmitting the detected update data to the second storage system; and
means for applying the update data to the second storage system in a manner that maintains consistency between data copied from the storage locations and update data, wherein the update data is transmitted to the second storage system before all the data as been copied from the storage locations in the first storage system to the second storage system, and wherein the update data is capable of being applied to the second storage system while copying data from the storage locations in the first storage system to the second storage system. - View Dependent Claims (12, 13, 14, 15, 16, 17)
-
-
18. A system for copying data, comprising:
-
a first storage system;
a second storage system;
means for copying update data to the first storage system to the second storage system;
means for suspending the copying of update data from the first storage system to the second storage system;
means for indicating in an update data structure all storage locations in the first storage system that received updates before and during the suspension of the copying; and
means for performing after ending the suspension;
(i) copying data from storage locations in the first storage system indicated in the update data structure to the second storage system;
(ii) transferring update data received after the suspension to storage locations in the first storage system to the second storage system; and
(iii) applying the update data to the second storage system in a manner that maintains consistency between data copied from the storage locations that is indicated in the update data structure and update data received after the suspension. - View Dependent Claims (19, 20)
-
-
21. An article of manufacture for copying data from a first storage system to a second storage system, wherein the article of manufacture causes operations to be performed, the operations comprising:
-
copying data from storage locations in the first storage system to the second storage system;
detecting update data to one storage location in the first storage system while copying data from storage locations in the first storage system to the second storage system;
storing the update data to the first storage system;
transmitting the detected update data to the second storage system; and
applying the update data to the second storage system in a manner that maintains consistency between data copied from the storage locations and update data, wherein the update data is transmitted to the second storage system before all the data as been copied from the storage locations in the first storage system to the second storage system, and wherein the update data is capable of being applied to the second storage system while copying data from the storage locations in the first storage system to the second storage system. - View Dependent Claims (22, 23, 24, 25, 26, 27)
-
-
28. An article of manufacture for copying data from a first storage system to a second storage system, wherein the article of manufacture causes operations to be performed, the operations comprising:
-
copying update data to the first storage system to the second storage system;
suspending the copying of update data from the first storage system to the second storage system;
indicating in an update data structure all storage locations in the first storage system that received updates before and during the suspension of the copying; and
after ending the suspension;
(i) copying data from storage locations in the first storage system indicated in the update data structure to the second storage system;
(ii) transferring update data received after the suspension to storage locations in the first storage system to the second storage system; and
(iii) applying the update data to the second storage system in a manner that maintains consistency between data copied from the storage locations that is indicated in the update data structure and update data received after the suspension. - View Dependent Claims (29, 30)
-
Specification