Abstract: An index associates fingerprints of file segments to container numbers of containers within which the file segments are stored. At a start of migration, a boundary is created identifying a current container number. At least a subset of file segments at a source storage tier are packed into a new container to be written to a destination storage tier. A new container number is generated for the new container. The index is updated to associate fingerprints of the at least subset of file segments to the new container number. A request is received to read a file segment. The index is queried with a fingerprint of the file segment to determine whether the request should be directed to the source or destination storage tier based on a container number of a container within which the file segment is stored.

Abstract: An index associates fingerprints of file segments to container numbers of containers within which the file segments are stored. At a start of migration, a boundary is created identifying a current container number. At least a subset of file segments at a source storage tier are packed into a new container to be written to a destination storage tier. A new container number is generated for the new container. The index is updated to associate fingerprints of the at least subset of file segments to the new container number. A request is received to read a file segment. The index is queried with a fingerprint of the file segment to determine whether the request should be directed to the source or destination storage tier based on a container number of a container within which the file segment is stored.

Abstract: Data containers are stored at a first cloud and include file segments managed by a deduplication file system. Metadata containers are written to a log, identified by a container ID generated sequentially, and include references to data containers. An index is maintained to map segment fingerprints to container IDs. Upon starting a migration to a second cloud, a checkpoint is created identifying a container ID at a head of the log. During migration, the index is updated to map fingerprints of migrated segments to new container IDs, and referencing new data containers having the migrated segments and written to the second cloud. A request to read a file is received. The index is examined to identify a container ID associated with a data container storing segments of the file. Based on the identified container ID and the checkpoint, the data container is accessed from the first or second cloud.

Abstract: A method for managing storage devices includes, in response to a first determination that a first cloud storage device is inaccessible to a local storage device, obtaining metadata objects from a second cloud storage device, identifying, based on a sync time analysis, at least one metadata object of the metadata objects to be deleted, initiating the deletion of the at least one metadata object on a second cloud storage device, wherein the second cloud storage device is accessible to the local storage device, and updating, after initiating the deletion of the at least one metadata object, a namespace on a local storage device.

Abstract: A method for managing storage devices includes, in response to a first determination that a first cloud storage device is inaccessible to a local storage device, obtaining metadata objects from a second cloud storage device, identifying, based on a sync time analysis, at least one metadata object of the metadata objects to be deleted, initiating the deletion of the at least one metadata object on a second cloud storage device, wherein the second cloud storage device is accessible to the local storage device, and updating, after initiating the deletion of the at least one metadata object, a namespace on a local storage device.