Data recovery with internet protocol replication with or without full resync
First Claim
1. A method of recovery in an asynchronous remote copy system having a primary file system at a primary site and a secondary file system at a secondary site, said method comprising:
- in response to the primary site becoming inoperative during read/write access to the primary file system and asynchronous remote copy of changes made to the primary file system being copied to the secondary file system, beginning read/write access to the secondary file system, making a snapshot copy of the secondary file system at the beginning of read/write access to the secondary file system, and keeping a record of changes made to the secondary file system during the read/write access to the secondary file system; and
thereafter, when the primary site becomes operative, using the snapshot copy to restore the primary file system to the state of the secondary file system existing when read/write access of the secondary file system was begun, and then writing into the primary file system the changes made to the secondary file system during the read/write access to the secondary file system; and
terminating read/write access to the secondary file system, and once the changes made to the secondary file system have been written into the primary file system, restarting read/write access to the primary file system and asynchronous remote copy of changes made to the primary file system being copied to the secondary file system.
9 Assignments
0 Petitions
Accused Products
Abstract
In an asynchronous remote copy system, a primary site keeps a list of data blocks for which changes have been made to a primary file system and transmitted to a secondary file system at a secondary site. When the primary site becomes inoperative, the secondary site begins read/write access to the secondary file system and keeps a snapshot copy of the restart point. Once the primary site becomes operative, the primary file system is restored to the state of the secondary file system at the restart point by using the list of data blocks for obtaining from the snapshot copy the data of the blocks for which changes had been made to the primary file system after the restart point. Then the primary file system is synchronized to the secondary file system, and read/write access is switched back from the secondary file system to the primary file system.
-
Citations
36 Claims
-
1. A method of recovery in an asynchronous remote copy system having a primary file system at a primary site and a secondary file system at a secondary site, said method comprising:
-
in response to the primary site becoming inoperative during read/write access to the primary file system and asynchronous remote copy of changes made to the primary file system being copied to the secondary file system, beginning read/write access to the secondary file system, making a snapshot copy of the secondary file system at the beginning of read/write access to the secondary file system, and keeping a record of changes made to the secondary file system during the read/write access to the secondary file system; and
thereafter,when the primary site becomes operative, using the snapshot copy to restore the primary file system to the state of the secondary file system existing when read/write access of the secondary file system was begun, and then writing into the primary file system the changes made to the secondary file system during the read/write access to the secondary file system; and
terminating read/write access to the secondary file system, and once the changes made to the secondary file system have been written into the primary file system, restarting read/write access to the primary file system and asynchronous remote copy of changes made to the primary file system being copied to the secondary file system. - View Dependent Claims (2, 3, 4)
-
-
5. A method of recovery in an asynchronous remote copy system having a primary file system at a primary site and a secondary file system at a secondary site, said method comprising:
-
in response to the primary site becoming inoperative during the asynchronous remote copy of changes made to the primary file system being copied to the secondary file system, beginning read/write access to the secondary file system, and then;
in response to the primary site becoming operative, synchronizing the primary file system to the secondary file system by beginning asynchronous remote copy of changes made to the secondary file system being copied to the primary file system, making a snapshot copy of the secondary file system at the beginning of the asynchronous remote copy of changes made to the secondary file system being copied to the primary file system, synchronizing the primary file system to the snapshot copy of the secondary file system, and once the primary file system has been synchronized to the snapshot copy of the secondary file system, terminating read/write access to the secondary file system and completing the asynchronous remote copy of changes made to the secondary file system being copied to the primary file system; and
once the asynchronous remote copy of changes made to the secondary file system has been completed, restarting the read/write access to the primary file system and asynchronous remote copy of changes made to the primary file system being copied to the secondary file system. - View Dependent Claims (6, 7)
-
-
8. A method of recovery in an asynchronous remote copy system having a primary file system at a primary site and a secondary file system at a secondary site, said method comprising:
-
in response to the primary site becoming inoperative during read/write access to the primary file system and asynchronous remote copy of changes made to the primary file system being copied to the secondary file system, beginning read/write access to the secondary file system, making a first snapshot copy of the secondary file system at the beginning of read/write access to the secondary file system, and keeping a record of changes made to the secondary file system during the read/write access to the secondary file system; and
thereafter,when the primary site becomes operative, making a second snapshot copy of the secondary file system, beginning asynchronous remote copy of changes made to the secondary file system since the second snapshot copy being copied to the primary file system, using the first snapshot copy to restore the primary file system to the state of the secondary file system existing when read/write access of the secondary file system was begun, and then writing into the primary file system the changes made to the secondary file system during the read/write access to the secondary file system between the time of the first snapshot copy and the second snapshot copy; and
terminating read/write access to the secondary file system, and once the changes made to the secondary file system have been written into the primary file system, restarting the read/write access to the primary file system and asynchronous remote copy of changes made to the primary file system being copied to the secondary file system. - View Dependent Claims (9, 10)
-
-
11. In an asynchronous remote copy system in which changes made to data blocks of a primary file system at a primary site are transmitted to a secondary file system at a secondary site, the primary site storing a list of the data bocks that have been changed in the primary file system, a method of recovery from a disruption at the primary site, said method comprising:
accessing the list of the data blocks that have been changed in the primary file system to restore the primary file system to a prior state at a restart point, the prior state at the restart point including changes made to the primary file system that have been transmitted to the secondary site, the primary file system being restored by determining from the list the data blocks that have been changed in the primary file system since the restart point, and obtaining from the secondary site the data existing at the time of the restart point in the data blocks that have been changed in the primary file system since the restart point, and writing into the primary file system the data existing at the time of the restart point in the data blocks that have been changed in the primary file system since the restart point. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18)
-
19. An asynchronous remote copy system comprising a primary data storage system and a secondary data storage system, the primary data storage system having a primary file system and the secondary data storage system having a secondary file system, the primary data storage system being programmed for read/write access to the primary file system and asynchronous remote copy of changes made to the primary file system being copied to the secondary file system,
wherein the secondary data storage system is programmed to respond to the primary data storage system becoming inoperative during the asynchronous remote copy of changes made to the primary file system being copied to the secondary file system by beginning read/write access to the secondary file system, making a snapshot copy of the secondary file system at the beginning of read/write access to the secondary file system, and keeping a record of changes made to the secondary file system during the read/write access to the secondary file system; - and
wherein the primary data storage system and the secondary data storage system are programmed for recovery when the primary data storage system becomes operative by using the snapshot copy to restore the primary file system to the state of the secondary file system existing when read/write access of the secondary file system was begun, and then writing into the primary file system the changes made to the secondary file system during the read/write access to the secondary file system, terminating read/write access to the secondary file system, and once the changes made to the secondary file system have been written into the primary file system, restarting read/write access to the primary file system and asynchronous remote copy of changes made to the primary file system being copied to the secondary file system. - View Dependent Claims (20, 21, 22)
- and
-
23. An asynchronous remote copy system comprising a primary data storage system and a secondary data storage system, the primary data storage system having a primary file system and the secondary data storage system having a secondary file system, the primary data storage system being programmed for read/write access to the primary file system and asynchronous remote copy of changes made to the primary file system being copied to the secondary file system,
wherein the secondary data storage system is programmed to respond to the primary data storage system becoming inoperative during the asynchronous remote copy of changes made to the primary file system being copied to the secondary file system by the secondary data storage system beginning read/write access to the secondary file system, and wherein the primary data storage system and the secondary data storage system are programmed to respond to the primary data storage system becoming operative by synchronizing the primary file system to the secondary file system by beginning asynchronous remote copy of changes made to the secondary file system being copied to the primary file system, making a snapshot copy of the secondary file system at the beginning of the asynchronous remote copy of changes made to the secondary file system being copied to the primary file system, synchronizing the primary file system to the snapshot copy of the secondary file system, and once the primary file system has been synchronized to the snapshot copy of the secondary file system, terminating read/write access to the secondary file system and completing the asynchronous remote copy of changes made to the secondary file system being copied to the primary file system; - and once the asynchronous remote copy of changes made to the secondary file system has been completed, restarting read/write access to the primary file system and asynchronous remote copy of changes made to the primary file system being copied to the secondary file system.
- View Dependent Claims (24, 25)
-
26. An asynchronous remote copy system comprising a primary data storage system and a secondary data storage system, the primary data storage system having a primary file system and the secondary data storage system having a secondary file system, the primary data storage system being programmed for read/write access to the primary file system and asynchronous remote copy of changes made to the primary file system being copied to the secondary file system,
wherein the secondary data storage system is programmed to respond to the primary data storage system becoming inoperative during the asynchronous remote copy of changes made to the primary file system being copied to the secondary file system by beginning read/write access to the secondary file system, making a first snapshot copy of the secondary file system at the beginning of read/write access to the secondary file system, and keeping a record of changes made to the secondary file system during the read/write access to the secondary file system; -
wherein the secondary data storage system is programmed to respond to the primary data storage system becoming operative by making a second snapshot copy of the secondary file system, and beginning asynchronous remote copy of changes made to the secondary file system since the second snapshot copy being copied to the primary file system; and
wherein the primary data storage system and the secondary data storage system are programmed for using the first snapshot copy to restore the primary file system to the state of the secondary file system existing when read/write access of the secondary file system was begun, and then writing into the primary file system the changes made to the secondary file system during the read/write access to the secondary file system between the time of the first snapshot copy and the second snapshot copy, and terminating read/write access to the secondary file system, and once the changes made to the secondary file system have been written into the primary file system, restarting read/write access to the primary file system and asynchronous remote copy of changes made to the primary file system being copied to the secondary file system. - View Dependent Claims (27, 28)
-
-
29. An asynchronous remote copy system comprising a primary data storage system and a secondary data storage system, the primary data storage system having a primary file system and the secondary data storage system having a secondary file system, the primary data storage system being programmed for read/write access to the primary file system and asynchronous remote copy of changes made to the primary file system being copied to the secondary file system, the primary data storage system storing a list of the data bocks that have been changed in the primary file system;
wherein the primary data storage system and the secondary data storage system are programmed for recovering from a disruption in the asynchronous remote copy of changes made to the primary file system being copied to the secondary file system by accessing the list of the data blocks that have been changed in the primary file system to restore the primary file system to a prior state at a restart point, the prior state at the restart point including changes made to the primary file system that have been transmitted to the secondary data storage system, the primary file system being restored by determining from the list the data blocks that have been changed in the primary file system since the restart point, and obtaining from the secondary data storage system the data existing at the time of the restart point in the data blocks that have been changed in the primary file system since the restart point, and writing into the primary file system the data existing at the time of the restart point in the data blocks that have been changed in the primary file system since the restart point. - View Dependent Claims (30, 31, 32, 33, 34, 35, 36)
Specification