Abstract: A method for accessing stored entities (SEs) that are stored in a storage unit of a storage system, the method may include determining in a cyclic manner, by each compute node (CN) of a group of compute nodes, CN SEs budgets to be used in a cycle, based on a shared storage space that stores performance requests of Ces of the group.

Abstract: A method for access control, the method may include (a) receiving, by a file server, an access request for allowing a user to access a file system entity, the user is identified by a first file system protocol (FSP) user identifier, (b) converting the first FSP user identifier to a first access control user identifier (ACUI) of the user, the first ACUI represents a combination of the user and the first FSP, (c) searching, within an access control data structure (ACUI), for a relevant access control rule associated with a member of a multiprotocol set of ACUIs of the user, wherein the multiprotocol set includes the first ACUI of the user and at least one other ACUI of the user that represents at least one combination of the user and at least one other FSP, and (d) responding to the access request based on the relevant access control rule, when finding the relevant access control.

Abstract: A method for storage system data aware compression, the method may include pre-compressing data units received by the storage system, by different pre-compression units to provide different pre-compressed versions of the data units; wherein the different pre-compression schemes are associated with different compression schemes, wherein at least some of the different compression schemes are data type specific compression schemes; calculating entropies of the different pre-compressed versions; and selecting a compression scheme out of the different compression schemes based on the entropies of the different pre-compressed versions.

Abstract: A method for contention reduced update of one or more storage system parameters, the method may include (i) concurrently monitoring the one or more storage system parameters (SSPs) by compute entities (CEs); wherein the concurrently monitoring comprises updating, by the CEs, local counters allocated to different SSPs; (ii) updating, by the CEs, sets of shared counter fields with values of the local counters, wherein different sets are allocated to different SSPs; wherein an updating of a set of a shared counter fields by an CE comprises selecting a shared counter field of the set by the CE; and (iii) calculating values of the different SSPs, wherein a calculating of a value of a SSP is based on at least one value of at least one shared counter field of a set that is allocated to the SSP.

Abstract: A method that includes instructing multiple compute entities, by an expansion manager and during a first phase of the stored entity metadata re-balancing, to: lookup any stored entity metadata by using: (a) a current translation function for linking identifiers of stored entities to stored entities metadata; wherein the current translation function is based on a size of a current storage space allocated to stored entities metadata; and (b) a next translation function for linking identifiers of stored entities to stored entities metadata; wherein the next translation function is based on a size of a next storage space allocated to stored entities metadata; wherein the current space is expanded during the expansion of the storage system to provide the next storage space, and to update any stored entity metadata accessed using the current translation function without updating stored entity metadata accessed using the next translation function.

Abstract: A method for compression of cells of a tabular database (TD), the method may include (i) receiving data elements, by a storage system; (ii) calculating a compressed representation (CR) of the data elements by applying a compression process that includes (ii.a) defining sets based on data element values, (ii.b) associating a set value per set; and (ii.c) generating the CR of the data elements based on differences between the data elements and corresponding set values; (iii) generating compression metadata related to the CR of the data elements, wherein the compression metadata comprises the set values and a mapping between the CR of the data elements and the set values; and (iv) storing, in the TD, the CR of the data elements.

Abstract: A method for importing data to a tabular database (TD), the method includes: determining that data was written, using a file system command, to a file system location; wherein the file system location is associated with at least a part of the TD; and automatically importing the data to the at least part of the TD.

Abstract: A system and method for using free space for recovering erasure coding data sets. The method includes segmenting at least one erasure coding data set into at least one stripe based on an erasure coding scheme, wherein each erasure coding data set includes chunks, wherein the chunks include chunks of systematic data and chunks of parity data; distributing the at least one stripe across non-volatile memory nodes based on the erasure coding scheme, wherein each non-volatile memory node is a unit of a non-volatile storage device; and upon a first failure of one of the non-volatile memory nodes: detecting that at least one of the non-volatile memory nodes that is not failed includes a first free space that does not currently store user data; and performing a first recovery process for recovering a first portion of the at least one erasure coding data set, based on the first free space.

Abstract: A method for recovery point objective compliant star replication, the method includes: obtaining, by a SSS, a user defined RPO value; performing replication iterations to each DSS according to replication schedules of the DSSs, wherein at least two DSSs of the multiple DSSs are assigned with replication schedules having different frequencies of replication iterations; wherein each replication iteration includes sending a content related to a scheduled snapshot; determining a conformance to the RPO, of a time elapsed since a content related to a last common snapshot was replicated to each one of the multiple DSSs; and performing a non-scheduled common (NSC) replication iteration to each of the multiple DSSs to prevent a violation of the RPO, wherein the NSC replication iteration includes sending content related to a NSC snapshot to each one of the multiple DSSs.

Abstract: A method for obtaining information related to a filesystem path in a file system that is stored in a storage system, the method may include (i) receiving a request to obtain hierarchy information related to file system entities stored under the filesystem path; and (ii) retrieving the hierarchy information; wherein the retrieving comprises accessing a filesystem hierarchy table that stores information regarding pathnames of file system entities of the file system; wherein the retrieving includes searching for path components of the filesystem path in subsets of cells of the filesystem hierarchy table, wherein each subset of cells is part of a set of cells that include path components of a certain pathname of a filesystem entity that belong to the file system.

Abstract: A method for striping, the method may include performing, for each period of time out of multiple periods of time, the steps of: (i) determining striping rules; wherein the determining of the striping rules may include selecting one or more selected stripe size values out of multiple stripe size value candidates; wherein the selecting is based on values of storage system parameters that are obtained when applying the multiple stripe size value candidates; wherein the storage system parameters comprise storage space utilization and storage system throughput; and (ii) applying the striping rules by the storage system, during the period of time; wherein the applying comprises obtaining data chunks; converting the data chunks to stripes having at least one of the one or more selected stripe size values; and storing the stripes in the storage system.

Abstract: A method for snapshot reversion, the method may include initializing a recovery of a storage system, from a failure that stopped a replication of a failed replication snapshot to an other storage system; wherein the other storage system reverted to an older snapshot not stored in the storage system; and reverting to the older snapshot, by the storage system using older snapshot metadata and data received from the storage system; wherein the older snapshot data may include a non-existing indication for a snapshot segment that existed in a snapshot that followed the older snapshot and not exists at the older snapshot, and wherein the data may include one or more older snapshot segments; wherein the reverting to the older snapshot is executed without undoing changes that were made since the older snapshot.

Abstract: A method for managing a read statement of a transaction, the method may include: (a) receiving the read statement, wherein the read statement is for receiving a data unit that is stored in a relational database; (b) finding one or more candidate versions of the data unit; wherein the finding may include: (i) accessing a database segment (DS) version metadata of one or more DS versions of one or more DSs that are related to the data unit and are stored in the relational database; (ii) performing a timestamp based determination that may include checking whether to ignore a database segment version when the database segment version metadata identifies the database segment version by a database segment commit timestamp; and (iii) performing a transaction metadata based determination of whether to ignore the database segment version when the database segment version metadata identifies the database segment version by a transaction identifier; and (c) responding to the read statement by outputting a version of the

Abstract: A method for monitoring a storage system, the method may include (a) generating a compute entity (CE) storage metric by each CE of a group of CEs to provide multiple CE storage metrics, wherein the multiple CE metrics are related to a monitoring period; and (b) calculating, during a calculation period, a group metric based on the multiple CE storage metrices; wherein the calculating includes performing multiple calculations iterations, wherein each calculation iteration includes (a) selecting an updating CE that belongs to the group of CEs and was not previously selected during the calculation period, (b) accessing, by the updating CE, a shared data structure that stores the group storage metric, and (c) updating the group storage metric using the CE storage metric of the updating CE.

Abstract: A method for selectively untying at least one of compression related links to a stale reference chunk, the method may include determining whether a compression effectiveness condition is fulfilled in relation to a set of referring chunks that are compressed using the stale reference chunk and are linked to the to the stale reference chunk by the compression related links; wherein the compression effectiveness condition is responsive to, at least, a number of the referring chunks of the set; and untying the at least one compression related links to the stale reference chunks when the compression effectiveness condition is not fulfilled.

Abstract: A method for storage system data aware compression, the method may include pre-compressing data units received by the storage system, by different pre-compression units to provide different pre-compressed versions of the data units; wherein the different pre-compression schemes are associated with different compression schemes, wherein at least some of the different compression schemes are data type specific compression schemes; calculating entropies of the different pre-compressed versions; and selecting a compression scheme out of the different compression schemes based on the entropies of the different pre-compressed versions.

Abstract: A method for monitoring largest file system entities of a file system that is stored in a storage system, the method may include populating, during multiple population iterations, a cache of the storage system with largest file system entities metadata; wherein a current population iteration of the multiple population iterations may include pushing, to a heap, metadata related to a set of one or more file system entities that are children of a parent file system entity that was deemed a largest file system entity of a last population iteration that preceded the current population iteration; popping the heap to provide a current largest file system entity; and storing metadata related to the current largest file system entity in the cache.

Abstract: A method for retrieving a file system entity at a presence of snapshot restore in a history of the file system entity , the method may include (i) receiving a request to obtain a content of the file system entity (FSE) at a certain point in time (PIT); and (ii) retrieving the content of the FSE at the certain point in time, wherein the retrieving comprises searching for FSE content segments to be included in a response to the request, wherein each FSE content segment has a write time that does not exceed the certain PIT, each FSE content segment is not included in a relevant blind period of time that is associated with a reversible snapshot restore operation, and fulfills another timing criterion.

Abstract: A method for contention reduced update of one or more storage system parameters, the method may include (i) concurrently monitoring the one or more storage system parameters (SSPs) by compute entities (CEs); wherein the concurrently monitoring comprises updating, by the CEs, local counters allocated to different SSPs; (ii) updating, by the CEs, sets of shared counter fields with values of the local counters, wherein different sets are allocated to different SSPs; wherein an updating of a set of a shared counter fields by an CE comprises selecting a shared counter field of the set by the CE; and (iii) calculating values of the different SSPs, wherein a calculating of a value of a SSP is based on at least one value of at least one shared counter field of a set that is allocated to the SSP.

Abstract: A method for lock metadata re-balancing upon an expansion of a storage system, the method may include instructing multiple compute entities, by an expansion manager and during a first phase of the lock metadata re-balancing, to acquire locks by using: (a) a current translation function for linking addresses of current lock metadata units (LMUs) to identifiers of stored entities; wherein the current translation function is based on a size of a current storage space allocated to the lock metadata; and (b) a next translation function for linking addresses of new LMUs to identifiers of stored entities; wherein the new translation function is based on a size of a new storage space allocated to the lock metadata; wherein the current space is expanded during the expansion of the storage system to provide the next storage space.