Infinidat Ltd.

International Business Machines Corporation

Sepaton, Inc.

Efraim Zeidner

Yechiel Yochai

Ido Ben-Tsion

Josef Ezra

Julian Satran

Shemer Schwarz

Alexander Winokur

Kenneth M Nagin

William Frank Micka

Ofir Zohar

Yoram Novick

Ehood Garmiza

Benny Rochwerger

Oded Cohn

Ido Ben Tsion

Michael Howard Hartung

Leo Corry

Israel Gold

Sivan Tal

Michael Dorfman

Ayelet Shani

Nir Schenkler

Joseph Ezra

Itamar Gilad

Nimrod Rotics

Udi N Rotics

A method for generating remote replicates of a logical volume at a remote site, the method comprises performing a plurality of replication cycles for generating a plurality (N) of points in time replicates of the logical volume at the remote site. Wherein for each positive integer n that ranges between 2 and N, a performing of a n'th replication cycle comprises: calculating in parallel and by multiple computerized resources of a storage system, multiple n'th point in time differences of multiple subsets of the logical volume; wherein n'th point in time differences of different subsets are calculated by different computerized resources; wherein a n'th point in time difference of a subset is a difference between an (n&#x2212;1)'th point in time content of the subset and an n'th point in time content of the subset; and sending, in parallel, the multiple n'th point in time differences to the remote site.

High speed asynchronous remote mirroring

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 storage system, a non-transitory computer readable medium and a method of pre-fetching. The method may include determining, by a pre-fetch module of the storage system, to fetch a certain data portion from a data storage device of the storage system to a cache memory of the storage system; wherein the certain data portion belongs to a certain statistical segment that belongs to at least one logical volume; determining, by a pre-fetch module of the storage system, to pre-fetch at least one additional data portion to the cache memory based upon input/output (I/O) activity statistics associated with the certain statistical segment; wherein the I/O activity statistics comprises timing information related to I/O activities; fetching the certain data portion; and pre-fetching the at least one additional data portion if it is determined to pre-fetch the at least one additional data portions.

Pre-fetching in 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 responding to an extent change operation, the method may include receiving, by a storage system and from a requesting entity, a request to perform an extent content change operation that involves changing a content of a certain extent within a logical space supported by a storage system; generating, in response to the request, extent change operation information that comprises (a) an event counter indicative of a time of requested occurrence of the extent change operation, (ii) a type of extent change operation indicator, and (ii) logical addresses associated with the extent change operation; and sending to the requesting entity an acknowledgement indicative of a completion of the extent change operation before a completion of the extent change operation if an expected content of the certain extent is known before completion of the extent change operation.

Managing read operations, write operations and extent change operations

Storage system(s) for storing data in physical storage in a recurring manner, method(s) of operating thereof, and corresponding computer program product(s). For example, a possible method can include: upon start of a storage recurrence, destaging dirty data which had been accommodated in the cache memory prior to the start of said storage recurrence thus giving rise to destaged data group, wherein destaging is provided with no overwriting of at least superseded data destaged before starting said storage recurrence while enabling retaining metadata indicative of location of said superseded data in the physical storage space; accommodating data obtained in said cache memory subsequent to the start of said storage recurrence while preventing said data from being destaged during said storage recurrence, thus giving rise to accommodated data group; and registering a point-in-time indicative of successful destaging of the destaged data group, thereby providing an order-preservation consistency indication corresponding to said recurrence.

Destaging cached data in multiple recurrences in a storage system

According to the teaching disclosed herein there is provided at least a method, system and device for managing a cache memory of a storage system. The storage system is associated with at least one physical storage device and, responsive to a read request, comprising information indicative of a logical address of at least one requested data unit, to obtain a storage physical address associated with the logical address, search the cache memory for a data unit associated with the storage physical address and service the request from the cache in case the data unit is found in the cache memory.

Avoiding duplication of data units in a cache memory of a storage system

A storage system and a method for managing a memory capable of storing metadata related to logical volume sets, are disclosed. A memory quota is assigned to a metadata related to a logical volume set. The size of a memory currently consumed by the metadata is monitored. Upon exceeding a threshold by the size of the monitored memory, at least one restraining action related to memory consumption by the metadata is applied.

Mass storage system and methods of controlling resources thereof

There are provided a mass storage system comprising a control layer operatively coupled to a physical storage space and operable to interface with one or more clients and to present to said clients a plurality of logical volumes. The method of operating the storage system comprises: dividing one or more logical volumes into a plurality of statistical segments with predefined size; assigning to each given statistical segment a corresponding activity level characterizing statistics of I/O activity with regard to data portions within the given statistical segment, said statistics collected over a plurality of cycles of fixed counting length; and managing one or more data storage processes in the storage system (e.g. a background defragmentation process, a background garbage collection process, a destage management process, etc.) using said activity level.

Mass data storage system and method of operating thereof

A method for operating a storage system, including storing data redundantly in the system and measuring respective queue lengths of input/output requests to operational elements of the system. The queue lengths are compared to an average queue length to determine respective performances of the operational elements of the storage system. In response to the average queue lengths and a permitted deviation from the average an under-performing operational element among the operational elements is identified. An indication of the under-performing operational element is provided to host interfaces in the storage system. One of the host interfaces receives requests for specified items of the data directed to the under-performing element, and in response to the indication, some of the requests are diverted from the under-performing operational element to one or more other operational elements of the storage system that are configured to provide the specified items of the data.

Performance of a storage system

A data storage apparatus includes a processor, a write cache in operable communication with the processor, an auxiliary storage device in operable communication with the write cache, and a temporary power source in electrical communication with each of the processor, write cache, and auxiliary storage device for supplying power in the event of a loss of primary, external power. The auxiliary storage device is dimensioned to have sufficient size for holding dirty pages cached in the write cache, and the temporary power source is configured with sufficient energy for, subsequent to the loss of the external power, powering the processor, the write cache, and the auxiliary storage device for an entire duration of a backup process.

Growing community of inventors

Haifa, Israel

Efraim Zeidner