Infinidat Ltd.

Josef Ezra

Yechiel Yochai

Efraim Zeidner

Ido Ben-Tsion

Ido Ben Tsion

Nir Schenkler

There is provided a storage system comprising a control layer operable to manage a snapshot family (SF) constituted by SF members having hierarchical relations represented by a SF relationship data structure and a method of operating thereof. Upon receiving a command for restoring a writable SF member from a read-only snapshot thereof, the control layer provides a foreground atomic operation. The atomic operation comprises generating a new writable snapshot of the read-only snapshot (a destination SF member), modifying the SF relationship data structure, and re-assigning all logical unit numbers (LUNs) from the writable SF member to be restored to the destination SF member. Upon successful completion of the atomic operation, the control layer sends acknowledgement indicative of successful restoring the writable SF member. The control layer further provides a background process comprising modifying, in correspondence with the provided atomic operation, a SF mapping data structure comprising mappings between logical and physical addresses corresponding to SF members.

Storage system capable of managing a plurality of snapshot families and method of operating thereof

There is provided a storage system capable to maintain a snapshot family comprising a plurality of members having hierarchical relations therebetween, and a method of operating thereof. The method comprises generating a mapping data structure with mapping entries each comprising mappings for mapping a logical address range associated with the mapping entry into physical address ranges respectively correlated to representative members of the snapshot family; omitting mappings corresponding to omitted member(s) different from any of the one or more representative members sharing a respective range of physical addresses; responsive to an access request directed to a certain logical address range and a certain omitted member, determining, using a predefined rule related to the hierarchical and sequential relations between members of the snapshot family, a representative member from the one or more representative members; and responding to the access request by using a physical address range correlated to the representative member.

Storage system and methods of mapping addresses of snapshot families

There is provided a storage system comprising a control layer operable to manage a plurality of snapshot families, each family constituted by snapshot family members having hierarchical relations therebetween. The method of operating the storage system comprises searching a cache memory for an addressed data block corresponding to an addressed LBA and associated with an addressed snapshot family and an addressed SF member. In a case of missing the addressed data block in the cache memory, identifying in the cache memory all dirty data blocks corresponding to the addressed LBA and associated with the addressed snapshot family (candidate data blocks); identifying among SF members of the addressed snapshot family a destage owner, and in a case when the identified destage owner is associated with a candidate data block, reading from the cache memory such candidate data block.

There is provided a storage system and a method of identifying delta-data therein between two points-in-time. The method comprises: generating successive snapshots Sand Scorresponding to the two points-in-time; upon generating the snapshot S, searching the cache memory for data blocks associated with snap_version=i, thereby yielding cached delta-metadata; searching the SF mapping data structure for destaged data blocks associated with snap_version=i, thereby yielding destaged delta-metadata; and joining the cached delta-metadata and the destaged delta-metadata, thereby yielding delta-metadata indicative of the delta-data between points-in-time corresponding to the successive snapshots with Snap_ID=i and Snap_ID=i+1. The method operates with no need in copying, destaging to a dedicated location and/or any other special handling of data that needs to be transmitted to the RS system.

A method for managing physical resources of a storage system, the method may include transmitting, to a remote site, first information representative of a first snapshot of a logical entity; wherein the first snapshot is associated with first data that is stored in first physical addresses of the storage system; wherein the first physical addresses are mapped to first logical addresses; receiving from the remote site a first acknowledgment indicating that the first information was fully received by the remote site; and disassociating, in response to a reception of the first acknowledgement, the first snapshot from the first physical addresses while maintaining a logical association between the first snapshot and the first logical addresses.

Managing physical resources of a storage system

A method for a snapshot family based reading of data units from a storage system, the method comprises: receiving a read request for reading a requested data entity, searching in a cache memory of the storage system for a matching cached data entity, if not finding the matching cached data entity then: searching for one or more relevant data entity candidates stored in the storage system; selecting, out of the one or more relevant data entity candidates, a selected relevant data entity that has a content that has a highest probability, out of contents of the one or more relevant data entity candidates, to be equal to the content of the requested data entity; and responding to the read request by sending the selected relevant data entity.

Storage system capable of managing a plurality of snapshot families and method of snapshot family based read

A method for providing a warranted snapshot that may include: receiving a request to create a first warranted snapshot of a first logical volume at a first point in time and creating the first warranted snapshot if the first warranted snapshot is non-writable and if an amount of physical storage actually devoted by a storage system to the first logical volume at the first point of time does not exceed a size of a free physical storage space that is available for storing any future data delta associated with the first warranted snapshot. The creating of the first warranted snapshot may include allocating a first virtual portion of a physical storage space for storing any future data delta associated with the first warranted snapshot. A size of the first virtual portion equals the amount of physical storage actually devoted to the first logical volume at the first point of time.

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Even Yehuda, Israel

Josef Ezra