Abstract: Examples described herein are generally directed to providing a fair amount of throughput to multiple clients of a storage system. According to one example, the storage system determines system metrics based upon use of the storage system by the clients. A system load value is calculated based upon the system metrics. The system load value quantifies a load on the storage system by the clients. Client loads, each representing a contribution to the use of the storage system by an individual client, are calculated and expressed as a relative degree or amount of the system load value. A target performance value for a client is calculated based on the client load for the client and a quality of service parameter value provisioned for the client to access the storage system. Based on the target performance value, latency for the client is introduced or removed.

Abstract: Techniques are provided for maintaining and recomputing reference counts in a persistent memory file system of a node. Primary reference counts are maintained for pages within persistent memory of the node. In response to receiving a first operation to link a page into a persistent memory file system of the persistent memory, a primary reference count of the page is incremented before linking the page into the persistent memory file system. In response to receiving a second operation to unlink the page from the persistent memory file system, the page is unlinked from the persistent memory file system before the primary reference count is decremented. Upon the node recovering from a crash, the persistent memory file system is traversed in order to update shadow reference counts for the pages with correct reference count values, which are used to overwrite the primary reference counts with the correct reference count values.

Abstract: Techniques are provided for replay of metadata and data operations. During initial execution of operations, identifiers of objects modified by the execution of each operation are identified and stored in association with the operations. When the operations are to be replayed (e.g., executed again, such as part of a replication operation or as part of flushing content from a cache to persistent storage), the identifiers are evaluated to determine which operations are independent with respect to one another and which operations are dependent with respect to one another. In this way, independent operations are executed in parallel and dependent operations are executed serially with respect to the operations from the dependent operations depend.

Abstract: Techniques are provided for selectively allowing or blocking services from utilizing snapshots. A splitter intercepts and assigns timestamps to operations for execution upon files of a file system. If a snapshot is created while there are no pending operation, then the snapshot is tagged to indicate that the snapshot was created while there were no pending operations, and the snapshot is considered a tagged snapshot. Otherwise, the snapshot is not tagged, and is considered an untagged snapshot. Storage services (e.g., backup applications, lifecycle management applications, applications that consider timestamps of files, etc.) are allowed to utilize tagged snapshots and are blocked from utilizes untagged snapshots in order to maintain consistency.

Abstract: Techniques are provided for utilizing a log to free pages from persistent memory. A log is maintained to comprise a list of page block numbers of pages within persistent memory of a node to free. A page block number, of a page, within the log is identified for processing. A reference count, corresponding to a number of references to the page block number, is identified. In response to the reference count being greater than 1, the reference count is decremented and the page block number is removed from the log. In response to the reference count being 1, the page is freed from the persistent memory and the page block number is removed from the log.

Abstract: Methods and systems for a storage environment are provided. One method includes copying a data unit from a first temporary storage location corresponding to each zoned solid-state drive (ZNS SSD) of a first ZNS SSD set of a storage system to a first XOR module, while determining a first partial horizontal parity using the data unit stored in the first temporary storage location; and determining a vertical parity for each ZNS SSD of the first ZNS SSD set using the data unit provided to the first XOR module in a current cycle and vertical parity determined from a previous cycle.

Abstract: A method for reducing write latency in a distributed file system. A write request that includes a volume identifier is received at a data management subsystem deployed on a node within a distributed storage system. The data management subsystem maps the volume identifier to a file system volume and maps the file system volume to a set of logical block addresses in a logical block device in a storage management subsystem deployed on the node. The storage management subsystem maps the logical block device to a metadata object for the logical block device on the node that is used to process the write request. The mapping of the file system volume to the set of logical block addresses in the logical block device enables co-locating the metadata object with the file system volume on the node, which reduces the write latency associated with processing the write request.

Abstract: A system, method, and machine-readable storage medium for forming a community based on a common set of attributes are provided. In some embodiments, the method includes creating a list of entities associated with a plurality of users, each entity included in the list of entities being accessed by a user of the plurality of users. The method also includes identifying a first entity accessed by a group of users of the plurality of users. The method further includes determining a first set of entities accessed by each user of the group of users, the first set of entities being included in the list of entities. The method also includes removing the first entity and the first set of entities from the list of entities. The method further includes forming a first community including the group of users, the first entity, and the first set of entities.

Abstract: Multi-site distributed storage systems and computer-implemented methods are described for improving a resumption time of input/output (I/O) operations during an automatic unplanned failover (AUFO). A computer-implemented method includes monitoring, with a second cluster, heartbeat information received at ultra-short time intervals from a first connection of one or more storage objects of the first cluster, determining, with the second cluster, whether the heartbeat information from the first connection is received during an ultra-short time interval, and intelligently routing heartbeat information from the one or more storage objects of the first cluster from the first connection to a second connection when the heartbeat information from the first connection is not received during the ultra-short time interval.

Abstract: Redistribution of files in a containerized distributed file system is disclosed. Containers each have an engine and a scanner and each of the containers stores files and parameters for characteristics of files stored on the container. A first engine in a first container monitors characteristics of files stored on the first container and, responsive to determining that the parameters for files on the first container exceed one or more predetermined thresholds, communicates with a second engine in a second container to determine a destination container for one or more files from the first container. The second engine in the second container indicates to the first engine in the first container whether the second container is available to receive one or more files from the first container. The first engine triggers file system scanning by the scanner of the first container to identify files to be moved to the second container.

Abstract: Techniques are provided for caching data during an on-demand restore using a cloud block map. A client may be provided with access to an on-demand volume during a restore process that copies backup data from a snapshot within a remote object store to the on-demand volume stored within local storage. In response to receiving a request from the client for a block of the backup data not yet restored from the snapshot to the on-demand volume, the block may be retrieved from the snapshot in the remote object store. The block may be cached within a cloud block map stored within the local storage as a cached block. The client may be provided with access to the cached block.

Abstract: One or more techniques and/or computing devices are provided for managing an arbitrary set of storage items using a granset. For example, a storage controller may host a plurality of storage items and/or logical unit numbers (LUNs). A subset of the storage items are grouped into a consistency group. A granset is created for tracking, managing, and/or providing access to the storage items within the consistency group. For example, the granset comprises application programming interfaces (APIs) and/or properties used to provide certain levels of access to the storage items (e.g., read access, write access, no access), redirect operations to access either data of an active file system or to a snapshot, fence certain operations (e.g., rename and delete operations), and/or other properties that apply to each storage item within the consistency group. Thus, the granset provides a persistent on-disk layout used to manage an arbitrary set of storage items.

Abstract: Techniques are provided for volume group backup, volume group restore, and volume group garbage collection for volume groups backed up to an object store. A volume group workflow is implemented to orchestrate individual consistent volume workflows that are separately and individually implemented by nodes hosting constituent volumes of a volume group. The volume group workflow and the individual consistent volume workflows are performed to back up the volume group to the object store, restore a volume group backup from the object store to a restore destination, and/or perform garbage collection on slots of objects storing data unique to a volume group backup to delete.

Abstract: Techniques are provided for tiering snapshots to archival storage in remote object stores. A restore time metric, indicating that objects comprising snapshot data of snapshots created within a threshold timespan are to be available within a storage tier of a remote object store for performing restore operations, may be identified. A scanner may be executed to evaluate snapshots using the restore time metric to identify a set of candidate snapshots for archival from the storage tier to an archival storage tier of the remote object store. For each candidate snapshot within the set of candidate snapshots, the scanner may evaluate metadata associated with the candidate snapshot to identity one or more objects eligible for archival from the storage tier to the archival storage tier, and may archive the one or more objects from the storage tier to the archival storage tier.

Abstract: Techniques are provided for on-demand creation and/or utilization of containers and/or serverless threads for hosting data connector components. The data connector components can be used to perform integrity checking, anomaly detection, and file system metadata analysis associated with objects stored within an object store. The data connector components may be configured to execute machine learning functionality to perform operations and tasks. The data connector components can perform full scans or incremental scans. The data connector components may be stateless, and thus may be offlined, upgraded, onlined, and/or have tasks transferred between data connector components. Results of operations performed by the data connector components upon base objects may be stored within sibling objects.

Abstract: Systems and methods are provided for learning normal behavior for user roles of an application running within a cluster of container orchestration platform and based thereon proactively taking action responsive to suspicious events. According to one embodiment, an event data stream is created by an API server of the cluster. The data for each event includes information regarding a request made to an API exposed by the API server with which the event is associated and a user of the application by which the event was initiated. The data is augmented with a role associated with the user and an anomaly threshold for the role. Normal behavior is learned by an ML algorithm of respective user roles by processing the augmented data. When an anomaly score associated with a particular event is output by the ML algorithm that exceeds the anomaly threshold, a predefined or configurable action is triggered.

Abstract: One or more techniques and/or computing devices are provided for resynchronization. For example, a request may be received to create pseudo snapshots of a first consistency group, hosted by a first storage controller, and a second consistency group, hosted by a second storage controller, having a synchronous replication relationship with the first consistency group. Incoming client write requests are logged within an intercept tracking log at the first storage controller. After a first drain without hold of incoming write requests is performed, a first pseudo common snapshot of the second consistency group is created. After a second drain without hold of incoming write operations is performed, a second pseudo common snapshot of the first consistency group and the intercept tracking log is created. The pseudo snapshots and the intercept tracking log (e.g., indicating a delta between the pseudo snapshots) are used to resynchronize the first and second consistency groups.

Abstract: Systems and methods for automated tuning of Quality of Service (QoS) settings of volumes in a distributed storage system are provided. According to one embodiment, one or more characteristics of a workload of a client to which a storage node of multiple storage nodes of the distributed storage system is exposed are monitored. After a determination has been made that a characteristic meets or exceeds a threshold, (i) information regarding multiple QoS settings assigned to a volume of the storage node utilized by the client is obtained, (ii) a new value of a burst IOPS setting of the multiple QoS settings is calculated by increasing a current value of the burst IOPS setting by a factor dependent upon a first and a second QoS setting of the multiple QoS settings, and (iii) the new value of the burst IOPS setting is assigned to the volume for the client.

Abstract: Multi-site distributed storage systems and computer-implemented methods are described for improving a resumption time of input/output (I/O) operations during an automatic unplanned failover (AUFO). A computer-implemented method includes determining, with a second storage cluster, whether heartbeat information from one or more storage objects of a CG of a first set of CGs is received during a time period, determining an out of sync state for a data replication relationship between the CG of the first set of CGs and a mirrored CG of a second set of CGs when the heartbeat information is not received during the time period and sending a single bulk role change call with a cluster identifier from the second cluster to an external mediator to provide a role change from follower to leader in the second set of CGs.

Abstract: Methods and systems for co-locating journaling and data storage are provided. Separate journal and volume partitions may be maintained within each logical storage unit (e.g., Logical Unit Number (LUN)) of a distributed storage system. Journaling of metadata associated with write requests received from one or more clients may be distributed by identifying a destination logical storage unit to which data associated with a given write request is to be stored and causing the data and metadata to be persisted to disk by journaling the metadata and the data to respective portions of an active log within the journal partition of the destination logical storage unit. By using the same logical storage unit for both journaling of write requests and writing the data associated with such write requests, the bottleneck due to there being only a single device or storage unit handling all metadata for all write requests can be avoided.