Recovering snapshots from a cloud snapshot lineage on cloud storage to a storage system

1. An apparatus comprising:

at least one processing device comprising a processor coupled to a memory;

the at least one processing device being configured:

to identify a snapshot lineage comprising one or more snapshots of a given set of one or more storage volumes, the snapshot lineage comprising (i) a local snapshot lineage stored on at least one of one or more storage devices of a storage system and (ii) at least one cloud snapshot lineage stored on cloud storage of at least one cloud external to the storage system, the at least one cloud snapshot lineage comprising at least a subset of the one or more snapshots of the given set of one or more storage volumes that have been copied from the local snapshot lineage to the cloud storage of the at least one cloud external to the storage system;

to select at least one snapshot to recover from the at least one cloud snapshot lineage to the storage system;

to create a set of one or more new storage volumes on the storage system;

to generate a recovery map linking each of a set of one or more cloud storage volumes on the cloud storage of the at least one cloud that comprises data of the selected at least one snapshot to at least one of the set of one or more new storage volumes on the storage system; and

to recover the selected at least one snapshot from the at least one cloud snapshot lineage to the storage system by copying data from the set of one or more cloud storage volumes to corresponding linked ones of the set of new storage volumes on the storage system.

2. The apparatus of claim 1 wherein the given set of one or more storage volumes originated at the storage system.

3. The apparatus of claim 1 wherein the given set of one or more storage volumes originated at an additional storage system.

4. The apparatus of claim 1 wherein identifying the snapshot lineage comprises:

invoking an application programming interface to submit a request for a list of snapshots of the at least one cloud snapshot lineage; and

receiving a response to invoking the application programming interface, the response comprising the list of snapshots of the at least one cloud snapshot lineage.

5. The apparatus of claim 4 wherein selecting the at least one snapshot comprises selecting one of the snapshots from the list of snapshots of the at least one cloud snapshot lineage.

6. The apparatus of claim 1 wherein creating the set of one or more new storage volumes on the storage system comprises:

creating a new storage group on the storage system; and

creating the set of one or more new storage volumes as protected storage volumes in the new storage group.

7. The apparatus of claim 1 wherein generating the recovery map comprises, for a given cloud storage volume in the set of cloud storage volumes:

invoking an application programming interface to submit a request to prepare the given cloud storage volume for restore to a subset of the set of new storage volumes on the storage system, the request comprising a volume identifier associated with the given cloud storage volume and a snapshot set identifier for the snapshot lineage; and

receiving a response to invoking the application programming interface, the response comprising access volume information for the subset of the set of new storage volumes on the storage system, the access volume information comprising an externally addressable volume identifier for the subset of the set of new storage volumes on the storage system and volume identifiers for each new storage volume in the subset of the set of new storage volumes on the storage system.

8. The apparatus of claim 7 wherein the application programming interface comprises a representational state transfer application programming interface, and wherein the request comprises an endpoint uniform resource locator specifying a path parameter comprising a unique identifier of the storage system.

9. The apparatus of claim 1 wherein the at least one processing device is further configured to determine at least a subset of data of the selected at least one snapshot that is to be copied from the set of one or more cloud storage volumes to the set of one or more new storage volumes on the storage system, and wherein recovering the selected at least one snapshot from the at least one cloud snapshot lineage to the storage system comprises copying the determined subset of the data of the selected at least one snapshot from the set of one or more cloud storage volumes to corresponding linked ones of the set of new storage volumes on the storage system.

10. The apparatus of claim 9 wherein determining the subset of the data of the selected at least one snapshot comprises:

invoking an application programming interface to submit a request for a bitmap of data of the selected at least one snapshot to be recovered to the storage system, the request comprising a snapshot identifier for the selected at least one snapshot, at least one starting track location of the data of the selected at least one snapshot on the cloud storage, at least one track count of a number of tracks from the at least one starting track location on the cloud storage that comprise the data of the selected at least one snapshot; and

receiving a response to invoking the application programming interface, the response comprising the bitmap of the data of the selected at least one snapshot to be recovered to the storage system, the bitmap comprising, for each cloud storage volume in the set of cloud storage volumes comprising the data of the selected at least one snapshot: a cloud storage volume name; a volume name of the selected at least one snapshot; a count representing a size of the data of the at least one snapshot; and a pointer to an array comprising bitmaps of the tracks of the cloud storage volumes comprising the data of the selected at least one snapshot.

11. The apparatus of claim 10 wherein the request further comprises an identifier of a local snapshot in the snapshot lineage stored in the local snapshot lineage, the at least one starting track location specifies a comparison starting track location for comparison between the data of the selected at least one snapshot and data of the local snapshot in the snapshot lineage, and the at least one track count specifies a number of tracks from the comparison starting track location comprising data to be compared for differences between the selected at least one snapshot and the local snapshot in the snapshot lineage.

12. The apparatus of claim 1 wherein the at least one processing device is further configured, responsive to successfully recovering the selected at least one snapshot from the at least one cloud snapshot lineage to the storage system, to remove the selected at least one snapshot from the at least one cloud snapshot lineage on the cloud storage of the at least one cloud external to the storage system.

13. The apparatus of claim 1 wherein removing the selected at least one snapshot from the at least one cloud snapshot lineage comprises:

invoking an application programming interface to submit a request to clean up the at least one cloud snapshot lineage, the request comprising an identifier of the selected at least one snapshot; and

receiving a response to invoking the application programming interface, the response comprising an indication of success of removal of the selected at least one snapshot from the at least one cloud snapshot lineage.

14. The apparatus of claim 1 wherein the at least one processing device is part of the storage system.

15. A computer program product comprising a non-transitory processor-readable storage medium having stored therein program code of one or more software programs, wherein the program code when executed by at least one processing device causes the at least one processing device to perform steps of:

identifying a snapshot lineage comprising one or more snapshots of a given set of one or more storage volumes, the snapshot lineage comprising (i) a local snapshot lineage stored on at least one of one or more storage devices of a storage system and (ii) at least one cloud snapshot lineage stored on cloud storage of at least one cloud external to the storage system, the at least one cloud snapshot lineage comprising at least a subset of the one or more snapshots of the given set of one or more storage volumes that have been copied from the local snapshot lineage to the cloud storage of the at least one cloud external to the storage system;

selecting at least one snapshot to recover from the at least one cloud snapshot lineage to the storage system;

creating a set of one or more new storage volumes on the storage system;

generating a recovery map linking each of a set of one or more cloud storage volumes on the cloud storage of the at least one cloud that comprises data of the selected at least one snapshot to at least one of the set of one or more new storage volumes on the storage system; and

recovering the selected at least one snapshot from the at least one cloud snapshot lineage to the storage system by copying data from the set of one or more cloud storage volumes to corresponding linked ones of the set of new storage volumes on the storage system.

16. The computer program product of claim 15 wherein generating the recovery map comprises, for a given cloud storage volume in the set of cloud storage volumes:

invoking an application programming interface to submit a request to prepare the given cloud storage volume for restore to a subset of the set of new storage volumes on the storage system, the request comprising a volume identifier associated with the given cloud storage volume and a snapshot set identifier for the snapshot lineage; and

receiving a response to invoking the application programming interface, the response comprising access volume information for the subset of the set of new storage volumes on the storage system, the access volume information comprising an externally addressable volume identifier for the subset of the set of new storage volumes on the storage system and volume identifiers for each new storage volume in the subset of the set of new storage volumes on the storage system.

17. The computer program product of claim 15 wherein the program code when executed by the at least one processing device further causes the at least one processing device to perform the step of determining at least a subset of data of the selected at least one snapshot that is to be copied from the set of one or more cloud storage volumes to the set of one or more new storage volumes on the storage system, and wherein recovering the selected at least one snapshot from the at least one cloud snapshot lineage to the storage system comprises copying the determined subset of the data of the selected at least one snapshot from the set of one or more cloud storage volumes to corresponding linked ones of the set of new storage volumes on the storage system.

18. A method comprising steps of:

identifying a snapshot lineage comprising one or more snapshots of a given set of one or more storage volumes, the snapshot lineage comprising (i) a local snapshot lineage stored on at least one of one or more storage devices of a storage system and (ii) at least one cloud snapshot lineage stored on cloud storage of at least one cloud external to the storage system, the at least one cloud snapshot lineage comprising at least a subset of the one or more snapshots of the given set of one or more storage volumes that have been copied from the local snapshot lineage to the cloud storage of the at least one cloud external to the storage system;

selecting at least one snapshot to recover from the at least one cloud snapshot lineage to the storage system;

creating a set of one or more new storage volumes on the storage system;

generating a recovery map linking each of a set of one or more cloud storage volumes on the cloud storage of the at least one cloud that comprises data of the selected at least one snapshot to at least one of the set of one or more new storage volumes on the storage system; and

recovering the selected at least one snapshot from the at least one cloud snapshot lineage to the storage system by copying data from the set of one or more cloud storage volumes to corresponding linked ones of the set of new storage volumes on the storage system;

wherein the method is performed by at least one processing device comprising a processor coupled to a memory.

19. The method of claim 18 wherein generating the recovery map comprises, for a given cloud storage volume in the set of cloud storage volumes:

invoking an application programming interface to submit a request to prepare the given cloud storage volume for restore to a subset of the set of new storage volumes on the storage system, the request comprising a volume identifier associated with the given cloud storage volume and a snapshot set identifier for the snapshot lineage; and

receiving a response to invoking the application programming interface, the response comprising access volume information for the subset of the set of new storage volumes on the storage system, the access volume information comprising an externally addressable volume identifier for the subset of the set of new storage volumes on the storage system and volume identifiers for each new storage volume in the subset of the set of new storage volumes on the storage system.

20. The method of claim 18 further comprising determining at least a subset of data of the selected at least one snapshot that is to be copied from the set of one or more cloud storage volumes to the set of one or more new storage volumes on the storage system, and wherein recovering the selected at least one snapshot from the at least one cloud snapshot lineage to the storage system comprises copying the determined subset of the data of the selected at least one snapshot from the set of one or more cloud storage volumes to corresponding linked ones of the set of new storage volumes on the storage system.