Vast Data Ltd.

Emc IP Holding Company LLC

Hillel Costeff

Asaf Levy

Lior Kamran

Anton Kucherov

Zvi Schneider

Avi Goren

Alex Soukhman

Vladimir Zdornov

Vlad Zdornov

Asaf Weissman

Or Dahan

A method for metadata blocks access, the method includes (i) accessing, following a reception of an access request, a metadata block related to a file system entity; the metadata block is associated with a transaction identifier that is indicative of a transaction that is a most recent transaction that modified the metadata block; (ii) traversing, starting from the metadata block, metadata blocks that are transaction related, using linkage metadata within the metadata blocks; (iii) determining, based on an outcome of the traversing, a status of the transaction; (iv) when it is determined that the transaction was successfully completed then completing the access request by using content that was written by the transaction to the metadata block; and (v) when it is determined that the transaction failed then ignoring content that was written by the transaction to the metadata block.

Efficient transaction management

A method for writing data to a shared write buffer, the method includes (i) receiving, by a processing circuit of a compute node of a storage system, a write request for writing to the shared write buffer an information unit associated with an accessing entity located outside the storage system; wherein the shared write buffer is stored in a non-volatile memory of a storage node of the storage system; the storage node is in communication with the compute node; (ii) determining, by the processing circuit whether to (a) store the information unit in a non-shared segment of the shared write buffer, or (b) store the information unit in a shared segment of the shared write buffer while applying a locking mechanism; wherein the determining is based on parameters, the parameters include a writing parameter of the accessing entity, a writing latency parameter associated with the accessing entity, and a locking timing parameter; and (iii) storing the information unit according to the determination.

Writing data to a shared write buffer

A method for managing tasks in a storage system, the method may include: (a) obtaining, by a scheduler, a shared budget for background storage tasks and foreground storage tasks; (b) obtaining, by the scheduler, a background budget for background storage tasks; wherein the background budget is a fraction of the shared budget; (c) allocating, by the scheduler, resources to pending storage tasks according to the shared budget and the background budget; wherein the allocating comprises (i) allocating the shared budget while prioritizing foreground storage tasks over background storage tasks; and (ii) allocating the background budget to background storage tasks; and (d) participating, by the scheduler, in executing of storage tasks according to the allocation.

Scheduling storage tasks

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&#x2014;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.

Low latency data mirroring in a large scale storage system

A system and method for replicating a file system. The method includes: copying a portion of the file system from a first storage, wherein the at least a portion of the file system includes underlying data and metadata, wherein the metadata includes pointers to the underlying data and metadata defining a file system hierarchy; partitioning the copied data of the file system into a plurality of blobs, wherein the plurality of blobs includes a plurality of data blobs and a plurality of metadata blobs, wherein each data blob includes at least one portion of the underlying data; generating a plurality of filter objects based on the copied data, wherein each filter object includes a list of metadata blobs; and storing the plurality of blobs and the plurality of filter objects in a second storage.

System and method for replicating file systems in remote object storages

A method is disclosed for destaging data to a storage device set that is arranged to maintain M replicas of the data, the storage device set having M primary storage devices and N secondary storage devices, the method comprising: detecting a destage event; and in response to the destage event, destaging the data item that is stored in a journal, the destaging including: issuing M primary write requests for storing the data item, each of the M primary write requests being directed to a different one of the M primary storage devices; in response to detecting that L of the primary write requests have failed, issuing L secondary write requests for storing the data item, each of the L secondary write requests being directed to a different secondary storage device; updating a bitmap to identify all primary and secondary storage devices where the data item has been stored.

Dynamic data placement for replicated raid in a storage system

A clustered storage system in one embodiment comprises a plurality of nodes, with each of at least a subset of the nodes comprising a set of processing modules configured to communicate over one or more networks with corresponding sets of processing modules on other ones of the nodes. In conjunction with a failure of a first instance of a process running on a given one of the nodes and a subsequent restart of a second instance of the process, at least one of the processing modules is to identify at least one transfer buffer command of the first instance of the process, to identify a plurality of logically ordered commands of the first instance of the process, and to provide distinct treatment of the transfer buffer command relative to treatment of the logically ordered commands in a manner that ensures that the restart of the second instance of the process is not delayed to await completion of the transfer buffer command or the logically ordered commands.

Growing community of inventors

Tel Aviv, Israel

Hillel Costeff