Concurrent copy emulation
Causing an application on a host to access a point-in-time image on a storage system includes the application generating concurrent copy commands that are designed to cause data to be copied from a first location to a second location independent of whether the data is accessed by the host following initiating creation of a concurrent copy, intercepting concurrent copy commands and data generated by the application prior to sending the commands and data from the host to the storage system, transforming the concurrent copy commands and data to revised commands and data that are used to access the point-in-time image. Transforming the concurrent copy commands may include allocating temporary space on the storage system. The revised commands and data are sent from the host to the storage system. All commands generated by the application may be intercepted by the drivers layer. Only concurrent copy commands may be transformed.
1. A method of causing an application on a host to access a point-in-time image on a storage system, comprising:
the application generating concurrent copy commands that are designed to cause data to be copied from a first location to a second location independent of whether the data is accessed by the host following initiating creation of a concurrent copy;
intercepting concurrent copy commands and data generated by the application prior to sending the commands and data from the host to the storage system;
transforming the concurrent copy commands and data to revised commands and data that are used to access the point-in-time image; and
sending the revised commands and data from the host to the storage system.
2. A method, according to claim 1 , wherein the concurrent commands and data are intercepted by a drivers layer on the host.
3. A method, according to claim 1 , wherein transforming the concurrent copy commands includes allocating temporary space on the storage system.
4. A method, according to claim 3 , wherein the temporary space provides a consistent copy of data being copied by the application.
5. A method, according to claim 1 , wherein the host is coupled to the storage system using an ANSI FC-SB-3 Single-Byte Command Code Sets-3 Mapping Protocol for Fibre Channel connection.
6. A method, according to claim 1 , wherein all commands generated by the application are intercepted by the drivers layer.
7. A method, according to claim 6 , wherein only concurrent copy commands are transformed.
8. A non-transitory computer readable medium containing software that causes an application on a host to access a point-in-time image on a storage system, the software comprising:
executable code that intercepts concurrent copy commands and data generated by the application prior to sending the commands and data from the host to the storage system, the application generating concurrent copy commands that are designed to cause data to be copied from a first location to a second location independent of whether the data is accessed by the host following initiating creation of a concurrent copy;
executable code that transforms the concurrent copy commands and data to revised commands and data that are used to access the point-in-time image; and
executable code that sends the revised commands and data from the host to the storage system.
9. A non-transitory computer readable medium, according to claim 8 , wherein the concurrent commands and data are intercepted by a drivers layer on the host.
10. A non-transitory computer readable medium, according to claim 8 , wherein transforming the concurrent copy commands includes allocating temporary space on the storage system.
11. A non-transitory computer readable medium, according to claim 10 , wherein the temporary space provides a consistent copy of data being copied by the application.
12. A non-transitory computer readable medium, according to claim 8 , wherein the host is coupled to the storage system using an ANSI FC-SB-3 Single-Byte Command Code Sets-3 Mapping Protocol for Fibre Channel connection.
13. A non-transitory computer readable medium, according to claim 8 , wherein all commands generated by the application are intercepted by the drivers layer.
14. A non-transitory computer readable medium, according to claim 13 , wherein only concurrent copy commands are transformed.
15. A host system that causes an application to access a point-in-time image on a storage system, comprising:
a connector that couples the host system to the storage system; and
a drivers layer that communicates with the storage system through the connector, the drivers layer being accessed by the application that generates concurrent copy commands that are designed to cause data to be copied from a first location to a second location independent of whether the data is accessed by the host following initiating creation of a concurrent copy, the drivers layer intercepting concurrent copy commands and data generated by the application prior to sending the commands and data from the host system to the storage system and transforming the concurrent copy commands and data to revised commands and data that are used to access the point-in-time image.
16. A host system, according to claim 15 , wherein transforming the concurrent copy commands includes allocating temporary space on the storage system.
17. A host system, according to claim 16 , wherein the temporary space provides a consistent copy of data being copied by the application.
18. A host system, according to claim 15 , wherein the host is coupled to the storage system using an ANSI FC-SB-3 Single-Byte Command Code Sets-3 Mapping Protocol for Fibre Channel connection.
19. A host system, according to claim 15 , wherein all commands generated by the application are intercepted by the drivers layer.
20. A host system, according to claim 19 , wherein only concurrent copy commands are transformed.