Abstract: Techniques are provided for load balancing in a storage system using a storage system-driven host connectivity management process. For example, a load balancing process comprises monitoring a distribution of input/output (I/O) workload across resources of a storage system to detect for an occurrence of an I/O workload imbalance, generating updated connection information for a host system connected to the storage system, in response to detecting the occurrence of an I/O workload imbalance, and sending a request to the host system to discover the updated connection information for connecting to the storage system based on the updated connection information.

Abstract: An apparatus comprises a processing device configured to receive, from one of two or more storage nodes of a software-defined storage system comprising a write cache and persistent storage, a request to read a given portion of data. One or more portions of data in the persistent storage are also stored as read-only data in local storage of virtual computing instances implementing the storage nodes. The processing device is configured to read the given portion of data from the local storage of the virtual computing instances responsive to determining that the given portion of data is part of the read-only data in the local storage of the virtual computing instances, and to read the given portion of data from the write cache or persistent storage responsive to determining that the given portion of data is not part of the read-only data in the local storage of the virtual computing instances.

Abstract: A storage system memory or memory domain with N memory controllers is organized into N-1 same-size partitions per memory controller or N partitions per memory controller with one partition reserved as spare capacity. The unreserved partitions are assigned to mirror pairs of members such that a first triangular submatrix of a representative matrix of indexed memory controllers and indexed partitions is a transpose of a second triangular submatrix of the representative matrix. The resulting distribution of members is balanced such that additional loading on remaining memory controllers when one of the memory controllers becomes inaccessible is evenly distributed.

Abstract: A first storage system receives a request to migrate a volume from the first storage system to a second storage system, and commences a migration process to non-disruptively migrate the volume from the first storage system to the second storage system while the volume is being accessed by a host system. The first storage system sends a first request to the host system to discover information for connecting to the second storage system to allow the host system to access to the volume through the second storage system during the migration process. In addition, the first storage system sends a second request to the host system to discover information for disconnecting from the first storage system during a final stage of the migration process.

Abstract: Techniques are provided for load balancing in a storage system using a storage system-driven host connectivity management process. For example, a load balancing process comprises monitoring a distribution of input/output (I/O) workload across resources of a storage system to detect for an occurrence of an I/O workload imbalance, generating updated connection information for a host system connected to the storage system, in response to detecting the occurrence of an I/O workload imbalance, and sending a request to the host system to discover the updated connection information for connecting to the storage system based on the updated connection information.

Abstract: A method, computer program product, and computer system for receiving, by a computing device, an I/O request. It may be identified whether the I/O request is eligible for handling via a first path without also requiring handling via a second path. If the I/O request is eligible, the I/O request may be processed via the first path on a host I/O stack without processing the I/O request via the second path on a storage array I/O stack. If the I/O request is ineligible, the I/O request may be processed via the first path on the host.

Abstract: A storage cluster includes a group of data nodes having concurrent access to a shared filesystem. The shared filesystem is assigned to a first TLU of a first storage group. Other filesystems of the data nodes associated with the shared filesystem, such as snapshot copies of the shared filesystems and the root/configuration filesystems of the data nodes are assigned to TLUs of a second set of storage groups. The first storage group and the second set of storage groups are all associated with a Remote Data Replication (RDR) group for the storage cluster. An RDR facility is created between a storage array storing the shared filesystem and a backup storage array. The concurrently accessed shared filesystem and the filesystems of all data nodes accessing shared filesystem are replicated on the RDR facility to the backup storage array to enable failover of the storage cluster between sites.

Abstract: A host system may include a computational processing unit implemented using hardware and a hardware virtualizing and remote sharing (HVRS) server that virtualizes and shares the computational processing unit with other host systems, where the host system is directly connected to an internal fabric of a storage system. A storage system interface (SSI) of the host system may be directly connected to the internal fabric of the storage system and also directly connected to a same peripheral device interconnect as the CPU, the computational processing unit and/or other hardware resources of the host system. The SSI may communicate with storage resources of the storage system using remote direct memory access (RDMA) and zero-copy technologies. Such a host system may provide the storage capacity and data protection services of a storage system at relatively fast speeds e.g., comparable to non-volatile RAM on a host system configured for use as persistent memory.

Abstract: A backup data storage system includes non-volatile memory units, a disk interface coupled to at least some of the non-volatile memory units, a connection component that facilitates exchanging data with the backup data storage system, and a smart network interface controller, coupled to the disk interface and the connection component to provide tape emulation to a host coupled to the backup data storage system. The disk interface, the connection component, and the smart network interface controller may be coupled using a PCIe bus. Tape data written to the backup storage device may be stored on the non-volatile memory units. A processor coupled to the smart network interface controller and the disk interface may receive the data from the smart network interface controller and may provide the data to the disk interface to store the data on the non-volatile memory units. The connection component may be a FICON connection component.

Abstract: A storage node that maintains a replica of a logical volume for use in response to a failover trigger includes a data node with volatile memory in which a filesystem and its metadata and a VDM and its metadata associated with the replica are maintained prior to the failover trigger. The storage node also includes a SAN node in which data associated with the replica is maintained. The data is maintained in a RW (read-write) state by the SAN node prior to the failover trigger. However, the replica is presented in a RO (read-only) state by the storage node prior to the failover trigger. The storage node changes the in-memory state of the filesystem and VDM to RW responsive to the failover trigger. Because the filesystem and its metadata and VDM and its metadata are already in memory and the data is in a RW state in block storage the failover is completed relatively quickly.

Abstract: A host server in a server cluster has a memory allocator that creates a dedicated host application data cache in storage class memory. A background routine destages host application data from the dedicated cache in accordance with a destaging plan. For example, a newly written extent may be destaged based on aging. All extents may be flushed from the dedicated cache following host server reboot. All extents associated with a particular production volume may be flushed from the dedicated cache in response to a sync message from a storage array.

Abstract: A method of cache hit ratio simulation using a partial data set includes determining a set of sampled addresses, the set of sampled addresses being a subset of all addresses of a storage system of a storage environment. The method further includes using, by a simulation engine, a cache management algorithm to determine a cache hit ratio of the sampled addresses, the cache management algorithm being also used by a cache manager to place a portion of the addresses of the storage system into cache during a runtime operation. The method further includes determining a quantity of memory access operations to frequently accessed addresses in the set of sampled addresses, and correcting, by the simulation engine, the cache hit ratio of the sampled addresses based on the quantity of memory access operations to the frequently accessed addresses in the set of sampled addresses. The simulation also handles sequential operations accurately.

Abstract: In a storage system in which a storage array accesses cloud storage via a cloud gateway, the cloud gateway provides signals to control data rate between the storage array and the cloud. The signals may include commands to reduce or stop all volume streams or a select subset of volume streams. Data rate may be controlled on the basis of available buffering capacity of the cloud gateway and available bandwidth between the cloud gateway and cloud storage. The signals may be SCSI VU commands, where the cloud gateway is a SCSI initiator and the storage array is a SCSI target.

Abstract: Telemetry data gathered from active deployed SAN nodes is used to create a machine learning model that predicts storage system performance, e.g. in terms of response time. The telemetry data may be filtered to remove outlier values and less relevant information before creating the training dataset. Engineered features may be created that include types of data that are not present in the telemetry data. For example, data types from the telemetry data may be combined to create engineered features that are more relevant than the individual data types. The engineered features are included in the training dataset. The machine learning model may be used to test possible configurations for a planned SAN node based on expected workload and performance requirements. Outputted data may include satisfactory configurations for a planned storage system.

Abstract: A method for managing data includes obtaining, by a hypervisor on a host computing device, a write request for storing first data, and in response to the write request: identifying a first set of memory segments associated with the first data using a memory mapper, wherein the first set of memory segments is associated with a memory device, making a first determination that the memory device is local to the host computing device, and in response to the first determination: storing the first data in the first set of memory segments.

Abstract: A host server in a server cluster has a memory allocator that creates a dedicated host application data cache in storage class memory. A background routine destages host application data from the dedicated cache in accordance with a destaging plan. For example, a newly written extent may be destaged based on aging. All extents may be flushed from the dedicated cache following host server reboot. All extents associated with a particular production volume may be flushed from the dedicated cache in response to a sync message from a storage array.

Abstract: A host system may include a computational processing unit implemented using hardware and a hardware virtualizing and remote sharing (HVRS) server that virtualizes and shares the computational processing unit with other host systems, where the host system is directly connected to an internal fabric of a storage system. A storage system interface (SSI) of the host system may be directly connected to the internal fabric of the storage system and also directly connected to a same peripheral device interconnect as the CPU, the computational processing unit and/or other hardware resources of the host system. The SSI may communicate with storage resources of the storage system using remote direct memory access (RDMA) and zero-copy technologies. Such a host system may provide the storage capacity and data protection services of a storage system at relatively fast speeds e.g., comparable to non-volatile RAM on a host system configured for use as persistent memory.

Abstract: A method, computer program product, and computer system for receiving, by a computing device, an I/O request. It may be identified whether the I/O request is eligible for handling via a first path without also requiring handling via a second path. If the I/O request is eligible, the I/O request may be processed via the first path on a host I/O stack without processing the I/O request via the second path on a storage array I/O stack.

Abstract: A method, computer program product, and computer system for receiving, by a computing device, an I/O request. It may be identified whether the I/O request is eligible for handling via a first path without also requiring handling via a second path. If the I/O request is eligible, the I/O request may be processed via the first path on a host I/O stack without processing the I/O request via the second path on a storage array I/O stack. If the I/O request is ineligible, the I/O request may be processed via the first path on the host I/O stack and via the second path on the storage array I/O stack.

Abstract: Techniques for performing a restoration may include: creating a first snapshot of a primary file system at a first point in time; and at a second point in time, performing first processing to restore at least a portion of the primary file system from the first point in time. The first processing may include: creating a second snapshot of the first snapshot of the primary file system; exporting the second snapshot as a first target device; mounting the first target device as a read-write checkpoint file system; performing file system consistency processing on the read-write checkpoint file system; and subsequent to performing the file system consistency processing on the read-write checkpoint file system, restoring at least a portion of the primary file system from the second snapshot using the read-write checkpoint file system. The file system consistency processing may include correcting metadata inconsistencies of the read-write checkpoint file system.