System for migrating virtual tape volumes between filesystems

1. An apparatus comprising:

a virtual tape engine comprising:

a plurality of compute nodes each comprising non-transitory memory and at least one processor;

a mainframe host computer interface adapted to receive tape drive utility access commands from a mainframe host computer;

a storage array interface adapted to send input-output commands to a storage array and receive data from the storage array; and

a migration engine that:

sends input-output commands to the storage array to read a first data set from a source virtual tape volume that is a logical storage device presented by the storage array and where the first data set is logically stored, wherein the source virtual tape volume is associated with a source filesystem that is a data structure that describes how the first data set is logically stored on the source virtual tape volume; and

sends input-output commands to the storage array to write the first data set back to a target virtual tape volume presented by the storage array wherein the target virtual tape volume is a logical storage device corresponding to the source virtual tape volume, wherein the target virtual tape volume is associated with a target filesystem that is different than the source filesystem and the target filesystem is a data structure that describes how the first data set is logically stored on the target virtual tape volume;

wherein the first data set is stored on managed drives of the storage array and the storage array creates metadata that maps between the managed drives and the source virtual tape volume and the target virtual tape volume;

whereby the first virtual tape volume is migrated between different filesystems of at least one virtual tape library on the storage array without loading the data set on the mainframe host computer and without moving the data set to a different storage array.

2. The apparatus of claim 1 wherein a data set associated with the source virtual tape volume is characterized by a form and the migration engine modifies the form of the data set to generate the target virtual tape volume.

3. The apparatus of claim 2 wherein the migration engine modifies the form of the data set by changing compression state.

4. The apparatus of claim 2 wherein the migration engine modifies the form of the data set by changing encryption state.

5. The apparatus of claim 1 wherein the source virtual tape volume is in a source directory, and the migration engine locks virtual tape volume serial numbers in the source directory.

6. The apparatus of claim 1 wherein the target virtual tape volume is in a target directory, and the migration engine locks virtual tape volume serial numbers in the target directory.

7. The apparatus of claim 1 wherein the migration engine sends a third input-output command to the storage array to delete the source virtual tape volume.

8. The apparatus of claim 1 comprising a migration policy that defines at least one of the following attributes: a source directory from which virtual tape volumes will be migrated; a target directory to which virtual tape volumes will be migrated; a move after field that indicates an age at which virtual tape volumes become eligible to be migrated; a field indicating when migration should and/or should not be performed; a tape modification field that indicates how a data set of the virtual tape volume is to be modified; and a max tasks field that indicates a maximum number of virtual tape volumes that will be concurrently migrated.

9. The apparatus of claim 8 wherein the migration engine automatically triggers migration of the source virtual tape volume based on the migration policy.

10. The apparatus of claim 1 wherein the virtual tape engine provides the mainframe host computer with access to the source virtual tape volume during migration.

11. A method comprising:

with a virtual tape engine comprising a plurality of compute nodes each comprising non-transitory memory and at least one processor, a mainframe host computer interface adapted to receive tape drive utility access commands from a mainframe host computer, a storage array interface adapted to send input-output commands to a storage array and receive data from the storage array, and a migration engine:

sending input-output commands to the storage array to read a first data set from a source virtual tape volume that is a logical storage device presented by the storage array and where the first data set is logically stored, wherein the source virtual tape volume is associated with a source filesystem that is a data structure that describes how the first data set is logically stored on the source virtual tape volume; and

sending input-output commands to the storage array to write the first data set back to a target virtual tape volume presented by the storage array wherein the target virtual tape volume is a logical storage device corresponding to the source virtual tape volume, wherein the target virtual tape volume is associated with a target filesystem that is different than the source filesystem and the target filesystem is a data structure that describes how the first data set is logically stored on the target virtual tape volume;

wherein the first data set is stored on managed drives of the storage array and the storage array creates metadata that maps between the managed drives and the source virtual tape volume and the target virtual tape volume;

whereby the first virtual tape volume is migrated between different filesystems of at least one virtual tape library on the storage array without loading the data set on the mainframe host computer and without moving the data set to a different storage array.

12. The method of claim 11 wherein a data set associated with the source virtual tape volume is characterized by a form and comprising the migration engine modifying the form of the data set to generate the target virtual tape volume.

13. The method of claim 12 comprising the migration engine modifying the form of the data set by changing compression state.

14. The method of claim 12 comprising the migration engine modifying the form of the data set by changing encryption state.

15. The method of claim 11 wherein the source virtual tape volume is in a source directory, and comprising the migration engine locking virtual tape volume serial numbers in the source directory.

16. The method of claim 11 wherein the target virtual tape volume is in a target directory, and comprising the migration engine locking virtual tape volume serial numbers in the target directory.

17. The method of claim 11 comprising the migration engine sending a third input-output command to the storage array to delete the source virtual tape volume.

18. The method of claim 11 comprising generating a migration policy that defines at least one of the following attributes: a source directory from which virtual tape volumes will be migrated; a target directory to which virtual tape volumes will be migrated; a move after field that indicates an age at which virtual tape volumes become eligible to be migrated; a field indicating when migration should and/or should not be performed; a tape modification field that indicates how a data set of the virtual tape volume is to be modified; and a max tasks field that indicates a maximum number of virtual tape volumes that will be concurrently migrated.

19. The method of claim 18 comprising the migration engine automatically triggering migration of the source virtual tape volume based on the migration policy.

20. The method of claim 11 comprising the virtual tape engine providing the mainframe host computer with access to the source virtual tape volume during migration.