Abstract: A method, system, and computer program product for measuring latency in storage area networks comprising receiving a command from a node at a first time by a target in a storage area network, evaluating the command by the target, and returning a reply to the node from the target at a second time, wherein a difference between the second time and the first time is less than a time period indicative of a processing delay in the target, wherein the reply is considered a good status reply.

Abstract: Storage-based slow drain detecting and automated resolution is provided herein. A data storage system as described herein can include a memory that stores computer executable components and a processor that executes computer executable components stored in the memory. The computer executable components can include a switch query component that obtains a host transfer rate negotiated between a host device and a network switch from a host-connected port of the network switch; a comparison component that compares the host transfer rate to an array transfer rate negotiated between the network switch and a storage array; and a rate limiter component that limits a data transfer from the storage array to the host device to the host transfer rate in response to the host transfer rate being less than the array transfer rate.

Abstract: In a data processing system having multiple production hosts, each with a backup agent, interfaced to a storage array and to a backup server, an array I/O priority engine on the storage array establishes and enforces I/O priorities for I/O backup and production communications with the array to ensure that backup does not consume a disproportionate CPU processing and array bandwidth load or disrupt more critical production processing.

Abstract: Non-volatile cache in a host computer provides a storage tier in a system that includes at least one other tier of storage in a storage array. Selected data of a host device that represents a storage array production volume is stored in non-volatile cache. An MPIO driver in the host computer accesses the non-volatile cache or the storage array in response to an IO from a host application to the host device. A tiering engine in either the host computer or the storage array uses data access statistics to calculate which data should be promoted or demoted to non-volatile cache. Data access statistics indicative of access to non-volatile cache may be provided to the storage array by the host computer. Data changes may be aggregated by the host computer and asynchronously destaged to the storage array. Data changes or dirty data discard messages may be exchanged by peer host computer synchronously with a write operation.

Abstract: A system for improving backup performance includes an interface, a processor, and a memory. The interface is to receive a volume identifier to backup. The processor is to determine allocation for data of a volume associated with the volume identifier in a plurality of storage tiers to improve backup processing, move data based at least in part on the allocation, and backup data of the volume. The memory is coupled to the processor and configured to provide the processor with instructions.

Abstract: An information handling system includes a server and a storage array. The server includes a memory buffer that stores data for an operating system executed within the server. The server detects that a shut down of the server has been initiated, and provides a signal indicating that the shut down has been initiated. The storage array receives the signal from the server, and increases a service level objective of write commands from the server in response to the signal being received.

Abstract: An apparatus in one embodiment comprises a host device configured to communicate over a network with a storage system comprising a plurality of storage devices. The host device comprises a set of input-output queues and a multi-path input-output driver configured to select input-output operations from the set of input-output queues for delivery to the storage system over the network. The multi-path input-output driver is further configured to generate a command comprising a cluster identifier of a cluster that includes the first host device and at least a second host device, and to send the command to the storage system over the network. The command is configured for utilization by the storage system to verify that the second host device is part of the same cluster as the first host device. The command may further comprise a group identifier for utilization by the storage system to identify the first host device of the cluster having the cluster identifier.

Abstract: A method includes designating one or more particular portions of a storage volume of a storage system for inclusion in a sub-volume snapshot. The method further includes generating the sub-volume snapshot as a point-in-time copy that includes the one or more designated portions of the storage volume and excludes one or more non-designated portions of the storage volume. The method is performed by at least one processing device comprising a processor coupled to a memory. The storage volume illustratively comprises a logical unit of a virtual machine file system, with the one or more designated portions of the logical unit of the virtual machine file system illustratively comprising at least one virtual machine storage drive file of the virtual machine file system. In some embodiments, a bitmap or other data structure is maintained for the storage volume with particular entries in the data structure corresponding to respective ones of the portions.

Abstract: An apparatus in one embodiment comprises a host device that includes a set of input-output (IO) queues and a multi-path input-output (MPIO) driver that selects IO operations from the set of IO queues for delivery to a storage system over a network. The MPIO driver determines service level objectives (SLOs) for respective sources of the IO operations, determines latencies of storage devices of the storage system, assigns an initial time-to-become-urgent (TTBU) value to each of at least a subset of the IO operations based at least in part on the SLO of its source and one or more of the determined latencies, adjusts at least a subset of the TTBU values based at least in part on amounts of time spent by the corresponding IO operations in the set of IO queues, and selects IO operations from the set of IO queues for delivery to the storage system based at least in part on their respective TTBU values as adjusted.

Abstract: A storage system may include an interface configured to connect with a mainframe computing system. The interface converts the protocol used by the mainframe computing system to another protocol. Once the data, which may be present in a backup data stream, from the mainframe computing system is converted, the storage system may direct or transmit the backup data stream for further processing such as deduplication and/or compression. The de-duplicated and/or compressed backup data stream is then stored to storage of the storage system.

Abstract: Techniques for migrating data of a logical device from a source to a target system may include: obtaining a map indicating unused data portions of a logical device; issuing read commands from the target system to the source system to only read data from the source copy of the logical device for logical addresses that are not marked in the map as unused data portions; receiving the read data at the target system; writing the read data to second logical addresses of the target copy of the logical device on the target system; and marking logical addresses indicated by the map as corresponding to the unused data portions. The source system may also determine whether all data of a received read request that reads data from the logical device is included in an unused data portion and if so, return no read data and a specialized error condition.

Abstract: Service level objectives (SLOs) defined for a storage system are associated with virtual machines running on hosts. For an I/O operation for a virtual machine (VM) running on a host system, storage processing is performed on the I/O operation in accordance with the SLO defined for the VM. The same storage system-defined SLOs may be applied to VMs running on multiple host systems. SLOs may be maintained by the storage array and shared with one or more host systems in I/O communication with the storage system. SLOs may be defined using a user interface of a storage system, host system, virtualizer control station or other component of a storage network, and communicated to the storage system, which may maintain the SLOs, and may disseminate them to one or more hosts. The SLOs then may be associated with VMs running on the hosts and tagged to I/O communications corresponding to the VMs.

Abstract: Combinations of host ports and storage ports (e.g., I-T pairs) on a storage network that are zoned but not masked may be determined, without accessing a switch or network administrator. Heartbeat communications (heartbeats) may be transmitted from host systems to each storage device of a storage system of which the host system is aware, along the one or more I/O paths of which the host is aware to the storage port of the I/O path. The storage devices may include one or more nominal devices defined for I-T pairs for which I/O connectivity has not been defined for any storage devices. The storage system may maintain a master heartbeat (heartbeat) table that may include a plurality of entries, each entry corresponding to a combination of a host port, storage port and storage device, and storing a time stamp value for a most recent heartbeat received for the combination.

Abstract: Service level objectives (SLOs) defined for a storage system are associated with VMs running on hosts. For an I/O operation for a virtual machine (VM) running on a host system, storage processing is performed on the I/O operation in accordance with the SLO defined for the VM. The same storage system-defined SLOs may be applied to VMs running on multiple host systems. SLOs may be maintained by the storage array and shared with one or more host systems in I/O communication with the storage system. SLOs may be defined using a user interface of a storage system, host system, virtualizer control station or other component of a storage network, and communicated to the storage system, which may maintain the SLOs, and may disseminate them to one or more hosts. The SLOs then may be associated with VMs running on the hosts and tagged to I/O communications corresponding to the VMs.

Abstract: Techniques for transmitting data may include: receiving, at a host, an initiator data transfer rate indicating a communication rate at which an initiator port of the host communicates over a first path using a communications fabric with a target port of a data storage system; receiving, at the host, a target data transfer rate indicating a communication rate at which the target port of the data storage system communicates over the first path using the communications fabric with the initiator port of the host; determining, at the host, whether the initiator data transfer rate and the target data transfer rate are different; and responsive to determining that the initiator data transfer rate and the target data transfer rate are different, performing processing that limits a rate at which data is transmitted between the initiator and target ports in accordance with the initiator and target data transfer rates.

Abstract: Described herein are systems and techniques for determining when excessive I/O response times are not the fault of a storage port, but rather are caused by other factors or components on a storage network, for example, over-utilization of a host port. For one or more host ports and/or storage ports, a payload idle time (PIT) may be determined for each I/O operation, the PIT being the amount of time during which a storage port is waiting for a host port to be ready to send or receive data of the respective I/O operation. It may be determined whether one or more of the PITs includes an excessive idle time (EIT), where the EIT may be an amount of the PIT that is more than a predefined acceptable amount of time. The cause of the EIT may be determined.

Abstract: Example embodiments relate to a method, a system, and a computer program product for load balancing for port selection. The method includes determining a processing load for each storage port in a plurality of storage ports having variable processing power and calculating a delay characteristic for each storage port of the plurality of storage ports according to its processing load. A command then may be sent to a selected storage port of the plurality of storage ports according to the delay characteristics and a policy.

Abstract: In a data processing system having multiple production hosts, each with a backup agent, interfaced to a storage array and to a backup server, an array I/O priority engine on the storage array establishes and enforces I/O priorities for I/O backup and production communications with the array to ensure that backup does not consume a disproportionate CPU processing and array bandwidth load or disrupt more critical production processing.

Abstract: Techniques for processing I/O operations may include: receiving an I/O operation directed to a logical device having an associated service level objective with a target I/O response time; performing first processing that determines an estimated response time for the I/O operation, and determining, based on the estimated response time for the I/O operation and the associated service level objective, whether to delay the I/O operation by an additional amount of time thereby increasing a measured response time for the I/O operation by the additional amount. The first processing may include determining a fixed baseline amount of time for the I/O operation; determining a cumulative amount of time estimated to service pending I/O operation queued for service prior to the I/O operation; and determining an expected service time estimated for servicing the I/O operation. Moving averages maintained for different I/O types and sizes may be used in determining I/O service times.

Abstract: Embodiments provide for a primary storage array having multiple storage tiers. The multiple storage tiers include one or more performance tiers and at least one deduplicated storage tier storing deduplicated data. One embodiment provides for a data storage system including management logic to manage the deduplicated storage tier. The management logic can receive a request to store deduplicated data and respond to the request to store the deduplicated data based on workload statistics associated with the data. In one embodiment the response to the request includes storing at least a portion of the deduplicated data to a first storage device in the second set of storage devices and the workload statistics include input/output (I/O) statistics associated with the unit of deduplicated data. In other embodiments the response includes reallocating drives between storage tiers and/or providing migration hints with respect to data on the deduplicated storage tier.