Abstract: A method for supporting files names in a storage system, the method may include receiving a first protocol request for creating an object having a requested object name that comprises one or more sets of slashes, wherein the first protocol does not use the one or more sets as hierarchy separators; wherein each set of slashes comprises one or more consecutive slashes; determining a role of each set of the one or more sets in a second protocol that uses slashes as hierarchy separators; and generating a path name for accessing the object, when using either one of the first and second protocols, wherein the generating is based on the requested object name and the role of each set.

Abstract: A method for protecting a disaster recovery site, the method may include receiving by source compute nodes of a storage system, during source storage periods, write requests for storing content in the storage system; writing by source compute nodes, during the source storage periods, the content into the storage nodes of the storage system; maintaining replication compute nodes of the storage system deactivated during the source storage periods; reading the content by the replication compute nodes from the storage nodes during replication periods; participating, by the replication compute nodes, in outputting the content to one or more data recovery sites during the replication periods; and maintaining the source compute nodes deactivated during the source storage periods.

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.

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 generating a reconstructed version of a filesystem entity, the method may include (i) generating fallback retrieval metadata for a reconstructed version segment, when the reconstructed version segment is (a) associated with a corresponding intermediate version segment, and (b) the corresponding intermediate version segment is preceded by a corresponding most updated segment that does not exceed a fallback version of the filesystem entity; wherein the reconstructed version segment, the corresponding intermediate version segment and the corresponding most updated segment that does not exceed a fallback version have a same address range; (ii) generating a non-existing indicator for the reconstructed version segment, when the reconstructed version segment is (a) associated with the corresponding intermediate version segment, and (b) the corresponding intermediate version segment is not preceded by any corresponding most updated segment that does not exceed the fallback version; and (iii) maintaining

Abstract: A method for generating a reconstructed version of a filesystem entity, the method may include (i) generating fallback retrieval metadata for a reconstructed version segment, when the reconstructed version segment is (a) associated with a corresponding intermediate version segment, and (b) the corresponding intermediate version segment is preceded by a corresponding most updated segment that does not exceed a fallback version of the filesystem entity; wherein the reconstructed version segment, the corresponding intermediate version segment and the corresponding most updated segment that does not exceed a fallback version have a same address range; (ii) generating a non-existing indicator for the reconstructed version segment, when the reconstructed version segment is (a) associated with the corresponding intermediate version segment, and (b) the corresponding intermediate version segment is not preceded by any corresponding most updated segment that does not exceed the fallback version; and (iii) maintaining

Abstract: A method for cluster based searching for a value range stored in a storage system, the method may include receiving a request to find a certain value range within a set of information elements that are stored in a storage system; wherein the set of information elements comprises subsets of information elements associated with subset hash based filters; wherein different subsets of information elements are associated with different subset hash based filters; determining a certain cluster value of a certain cluster that comprises the certain value range; applying one or more hush functions on the certain cluster value to provide one or more hash results; and determining whether one or more members of the certain cluster are possibly in a subset of information elements, based on the one or more hash results and on a subset hash based filter of the subset of information elements; and when determining that the one or more members of the certain cluster are possibly in the subset then searching, within the subset,

Abstract: A method for user-defined validation of content stored in a storage system, the method may include receiving a request to execute a user-defined validation process (UDVP) on the content that is stored in the storage system; wherein the request is associated with means for executing the UDVP, and a content identifier; scheduling, by the storage system, at least one execution of the UDVP; executing the UDVP according to the scheduling to provide one or more validation results; and finding that the one or more validation results are indicative of potential security issues and performing one or more validation-triggered security measures.

Abstract: A method for resolving an erred input/output (IO) flow, the method may include (i) sending over a path a remote direct write request associated with a certain address range; wherein the path is formed between a compute node of a storage system to a storage drive of the storage system; (ii) receiving by the compute node an error message related to the remote direct write request; wherein the error message does not indicate whether an execution of the remote direct write request failed or is only temporarily delayed; (iii) responding by the compute node to the error message by (a) preventing from sending one or more IO requests through the path, (b) preventing from sending at least one IO requests aimed to the certain address range; and (c) requesting, using a management communication link, to force an execution of pending IO requests that are related to the path; and (iv) reuse the path, by the compute node, following an indication that there are no pending IO requests that are related to the path.

Abstract: A method for determining a progress of an execution of a task, the method may include accessing only a portion of a shared task status data structure that (a) is associated with the task, wherein the task is executed by a first plurality of compute elements, and (b) comprises multiple hierarchical levels; wherein an entry of a certain hierarchical level represents an aggregate progress associated with multiple entries of the another hierarchical level; the certain hierarchical level is higher than the other hierarchical level; and determining the progress of the execution of the task based on a content of the portion.

Abstract: A method for striping based on evaluated rules, the method may include determining a compatibility, with a storage system utilization policy, of storing stripes under evaluated rules; wherein the evaluated rules define a stripe size, a number of parity chunks per stripe, and maximal numbers of chunks within a stripe per different failure domains of different size ranges; checking whether the storing of the stripes is compatible with the storage system utilization policy; when finding that the storing of the stripes is not compatible then searching for one or more changes of one or more of the maximal numbers that yields compliant one or more maximal numbers that once applied results in a compliance with the storage system utilization policy; applying the compliant one or more maximal numbers when finding the compliant one or more maximal numbers; and determining that the evaluated failure domain rules are non-compliant when failing to find the compliant one or more maximal numbers.

Abstract: A method for traversal of a filesystem tree, the method may include traversing the filesystem tree by multiple processing entities of a set of processing entities that belong to a storage system; wherein the traversing comprises multiple iterations of on-the fly allocation of workload, associated with parallel traversing of the filesystem tree, among the multiple processing entities; wherein a current iteration of the on the fly allocation is (a) executed by a current group of processing entities that are currently assigned to traverse current nodes of the filesystem tree, and (b) comprises re-allocating by the current group, a traversal task for traversing one or more child nodes of each of the current nodes of the filesystem tree, to a next group of processing entities; wherein the current group and the next group belong to the set.

Abstract: A method for recovering failed chunks, the method may include (i) obtaining a failure indication about a failure of a first number (X1) of failed chunks; wherein the chunks were stored in a group of disks, the group of disks is configured to store a second number (?) stripes of multiple (N) chunks, wherein each stripe comprises a first plurality (K) of data chunks and a second plurality (R) of parity chunks; wherein R exceeds ( X ? 1 ? ) ; and (ii) performing at least one recovery iteration until fulfilling a stop condition. Each recovery iteration of the at least one recovery iteration may include (a.i) selecting valid chunks to provide selected valid chunks, wherein a number of selected chunks is smaller than a product of a multiplication of R by ?; (a.ii) retrieving valid data chunks that are relevant to the selected valid chunks; and (a.iii) attempting to reconstruct the failed chunks based on the retrieved chunks.

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 generating a reconstructed version of a filesystem entity, the method may include (i) generating fallback retrieval metadata for a reconstructed version segment, when the reconstructed version segment is (a) associated with a corresponding intermediate version segment, and (b) the corresponding intermediate version segment is preceded by a corresponding most updated segment that does not exceed a fallback version of the filesystem entity; wherein the reconstructed version segment, the corresponding intermediate version segment and the corresponding most updated segment that does not exceed a fallback version have a same address range; (ii) generating a non-existing indicator for the reconstructed version segment, when the reconstructed version segment is (a) associated with the corresponding intermediate version segment, and (b) the corresponding intermediate version segment is not preceded by any corresponding most updated segment that does not exceed the fallback version; and (iii) maintaining

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 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 low-latency data mirroring in a storage system, the method may include receiving, by a compute node of the storage system, a read request for reading a data unit stored at a primary storage block of the storage system; determining, by the compute node and based on primary storage block metadata, whether a content of the primary storage block is consistent; and responding to the determining of whether the content of the primary storage block is consistent. The responding may include (a) when determining that the primary storage block is inconsistent—copying the data unit from the primary storage block to a secondary storage block of the storage system, and updating the primary storage block metadata; and (b) reading the data unit from the primary storage block and sending the data unit to a requesting entity.

Abstract: A method for maintaining an availability of a storage system, the method may include obtaining, by a control module of the storage system, problem related information generated by one or more compute nodes of the storage system, the problem related information is indicative of one or more problems associated with an execution of one or more storage operations; determining, by the control module and based on the problem related information, whether to forbid an execution of a storage operation of the one of more storage operations; and updating, by the control module, and based on the determining, a forbidden storage operation data structure that is accessible to the compute nodes of the storage system.

Abstract: A method for hierarchical workload allocation in a storage system, the method may include determining to reallocate a compute workload of a current compute core of the storage system; wherein the current compute core is responsible for executing a workload allocation unit that comprises one or more first type shards; and reallocating the compute workload by (a) maintaining the responsibility of the current compute core for executing the workload allocation unit, and (b) reallocating at least one first type shard of the one or more first type shards to a new workload allocation unit that is allocated to a new compute core of new compute cores.