Abstract: 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.

Abstract: A storage system and method is provided including physical storage devices controlled by storage control devices constituting a storage control layer operatively coupled to the physical storage devices and hosts. The storage control layer includes: a first virtual layer interfacing with the hosts, operable to represent a logical address space characterized by logical block addresses and available to said hosts and characterized by an Internal Virtual Address Space (IVAS) and operable, responsive to a configuration or I/O request addressed to the logical block addresses, to translate said logical block addresses into IVAS addresses; and a second virtual layer interfacing with the physical storage devices, operable to represent an available physical space to said hosts and characterized by a Physical Virtual Address Space (PVAS), addresses in PVAS having corresponding address in IVAS. The second virtual layer is operable to translate said respective IVAS addresses into addresses in the physical address space.

Abstract: 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.

Abstract: A method of operating a storage system includes: configuring the address space so that each LBA is assigned to at least two servers among a plurality of at least three servers in a control grid: to a primary server with a primary responsibility for handling requests corresponding to said LBA, and to a secondary server with a secondary responsibility for handling requests corresponding to said LBA. In response to a request corresponding to a certain LBA range, generating by a data server having primary responsibility over the certain LBA range, a primary cache object; identifying a data server configured as a secondary data server with regard to the certain LBA range; and generating a redundancy cache object corresponding to the primary cache object only at the identified secondary data server, the redundancy cache object to be used by the identified secondary data server when taking the primary responsibility.

Abstract: The presently disclosed subject matter includes a method and system for enabling the deletion of logical objects characterized by an object identifier (OID). Upon restart following a system interruption, one or more logical objects are identified, each object being addressed by an interrupted delete request. For each identified logical object performing a deletion, the deletion including: reading one or more physical blocks stored in a physical storage space, wherein the one or more physical blocks were linked to the identified logical object before the system interruption, each of the physical blocks includes an OID stored therein indicating a logical object currently linked to the respective physical block; obtaining OIDs stored respectively in the one or more physical blocks; and freeing those physical blocks from among the one or more physical blocks, which store an OID identical to the respective OID of the identified logical object.

Abstract: A request for obtaining a space allocation descriptor is received by a block control layer of a storage system. The space allocation descriptor is indicative of one or more logical blocks free for allocation within a range of logical addresses. The range of logical addresses is included within a logical address space related to an upper layer application which has issued the request. The space allocation descriptor is provided by using a data structure included in the block control layer and operative to map between the logical address space and allocated storage blocks within a physical storage space, managed by the block control layer.

Abstract: 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 Si and Si+1 corresponding to the two points-in-time; upon generating the snapshot Si+1, 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: In accordance with certain aspects of the presently disclosed subject matter, there is provided a storage system and a method of storing data thereof. The method comprises: storing a plurality of snapshots of a certain source; assessing to at least one given snapshot an assessed value characterized by at least one of the following values and/or derivatives thereof: i. a first value characterizing the amount of unique physical data blocks associated, merely, with said given snapshot; ii. a second value characterizing the amount of unique physical blocks associated merely with a certain group of snapshots comprising said given snapshot; iii a combination of the first and the second value; and updating the assessed value responsive to a pre-defined event.

Abstract: A method and system is disclosed for storage optimization of thin provisioning. Non-zero data units within data portions are re-allocated to specifically designated one or more areas in the physical storage space and the physical address of the non-zero data unit within the designated area is associated with the logical address of the non-zero data unit. In case the data portion is allocated to the physical storage, the physical storage space initially allocated to the data portion is returned to the pool of available physical storage space, thereby freeing the storage space for storing other data.

Abstract: The presently disclosed subject matter includes, inter alia, a storage system and a method of managing allocation of data in case an enclosure in a storage system becomes unavailable. The storage system has a storage space configured as a plurality of RAID groups, each RAID group comprising N parity members. According to one aspect of the disclosed subject matter, responsive to a write request, at least one section allocated to a disk in an unavailable enclosure is identified; at least one temporary RAID group in a spare storage space of the storage system is allocated and data related to the write request is written to the alternative RAID group.

Abstract: 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.

Abstract: There is provided a storage control grid capable of controlling at least one service provided in the storage system and a method of operating thereof. The storage control grid comprises at least one service dispatcher operatively coupled to at least one service requestor and to a plurality of service providers. The method comprises requesting by service requester a service, thus giving rise to at least one service request; enabling, using said at least one service dispatcher, delivery of the service request to at least one service provider among said plurality of service providers, said service provider configured to provide said at least one service, wherein the delivery is enabled in accordance with data comprised in a service data structure handled by said at least one service dispatcher and indicative, at least, of association between said at least one service and service providers among said plurality of service providers.

Abstract: A method for managing resources in a storage pool of external virtual memory, that includes a host manager being associated with a storage pool by a storage manager. The host manager manages the resources, the managing including creating resources in the storage pool and/or deleting resources in the storage pool. The host manager further accesses the resource in the pool, such accessing including reading data to or writing data to the resource.

Abstract: A virtual allocation unit is allocated in a virtual address space corresponding to a filesystem, in response to an allocation requirement, related to a logical object in the filesystem. The size of the virtual allocation unit is determined in accordance with the current physical size of the logical object. The size of the virtual allocation unit is substantially larger than a size required with respect to the allocation requirement. Physical block address ranges are allocated in a physical storage space, in response to subsequent write requests, related to the logical object. Each physical block address range is associated with a respective portion of the virtual allocation unit.

Abstract: Storage system(s) for providing 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 for each recurrence: generating a snapshot of at least one logical volume; destaging all data corresponding to the snapshot which was accommodated in the cache memory prior to a time of generating the snapshot and which was dirty at the time of generating said snapshot, thus giving rise to destaged data group; and after the destaged data group has been successfully destaged, registering an indication that the snapshot is associated with an order preservation consistency condition for the at least one logical volume, thus giving rise to a consistency snapshot.

Abstract: A system and method of operating a filesystem for managing filesystem objects is disclosed. The filesystem objects are characterized by metadata parameters included in a global directory object arranged in a plurality of global directory object (GDO) pages. Responsive to receiving a request for creating a new filesystem object, a parent key is obtained. The parent key is indicative of an identifier of a direct parent directory requested for hosting the new filesystem object. A target page that corresponds to the parent key is located within the plurality of GDO pages. The target page further includes a direct parent directory metadata record associated with the direct parent key and includes metadata parameters related to the direct parent directory. An object key is created as corresponding to the same target page, thereby enabling accommodation of an object metadata record, related to the new filesystem object, on the target page.

Abstract: There is provided a storage arrangement and a method of operating thereof. The storage arrangement comprises a first storage system and one or more second storage systems operatively coupled to the first storage system. First control layer is operable to handle a first logical address space comprising a first logical group characterized by a plurality of logical block addresses; first control layer comprises a first mapping module handling a first mapping structure associated with first logical group. Each second control layer comprises, respectively, a second mapping module handling a second mapping structure associated with first logical group.