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: Techniques for processing I/O operations may include: detecting, at a host, a sequence of I/O operations to be sent from the host to a data storage system, wherein each of the I/O operations of the sequence specifies a target address included in a first logical address subrange of a first logical device; sending, from the host, the sequence of I/O operations to a same target port of the data storage system, wherein each of the I/O operations of the sequence includes an indicator denoting whether resources used by the same target port in connection with processing said each I/O operation are to be released subsequent to completing processing of said each I/O operation; receiving the sequence of I/O operations at the same target port of the data storage system; and processing the sequence of I/O operations.

Abstract: Storage group performance targets are achieved by managing resources using discrete techniques that are selected based on learned cost-benefit rank. The techniques include delaying start of IOs based on storage group association, making a storage group active or passive on a port, and biasing front end cores. A performance goal may be assigned to each storage group based on volume of IOs and the difference between an observed response time and a target response time. A decision tree is used to select a correction technique which is biased based on the cost of deployment. The decision tree maintains an average benefit of each technique and over time with rankings based on maximizing cost-benefit.

Abstract: Techniques for processing I/O operations may include: detecting, at a host, a sequence of I/O operations to be sent from the host to a data storage system, wherein each of the I/O operations of the sequence specifies a target address included in a first logical address subrange of a first logical device; sending, from the host, the sequence of I/O operations to a same target port of the data storage system, wherein each of the I/O operations of the sequence includes an indicator denoting whether resources used by the same target port in connection with processing said each I/O operation are to be released subsequent to completing processing of said each I/O operation; receiving the sequence of I/O operations at the same target port of the data storage system; and processing the sequence of I/O operations.

Abstract: Preventing timeouts of I/O requests at a data storage system that are associated with cloud-based and/or external data storage systems. Rather than allow a timeout to occur, a response is sent to the host at a predetermined time before timeout, which will prevent the timeout from occurring and may cause the host system to “retry” the I/O operation by issuing another I/O request specifying the same I/O operation. The data storage system may repeat this process a preconfigured number of times or indefinitely, or until the host or user terminates or the application crashes. An I/O request received from a host may be configured in accordance with one or more SAN- or NAS-based protocols, and the I/O request may be translated into an I/O request conforming to one or more cloud-based and/or Internet-based protocols and transmitted to a cloud-based and/or external storage system.

Abstract: A storage array in one embodiment is configured to communicate over one or more networks with a plurality of host devices. The storage array is further configured to detect process tags assigned to respective input-output operations by a given one of the host devices, the process tags being of at least first and second distinct types so as to distinguish at least respective first and second distinct processes generating corresponding ones of the input-output operations on the given host device. Responsive to a particular one of the detected process tags being of the first type, the storage array provides a first level of priority for processing of the corresponding input-output operation, and responsive to a particular one of the detected process tags being of the second type, the storage array provides a second level of priority different than the first level of priority for processing of the corresponding input-output operation.

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 receive per-host path change information from the storage system indicating a change in at least one path from the host device to the storage system, to automatically initiate a path discovery scan in the host device based at least in part on the received per-host path change information, and to add one or more new paths identified in the path discovery scan to a set of active paths for the host device. The per-host path change information received from the storage system may comprise a value of a path change counter maintained by the storage system for the host device.

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 receive per-host path change information from the storage system indicating a change in at least one path from the host device to the storage system, to automatically initiate a path discovery scan in the host device based at least in part on the received per-host path change information, and to add one or more new paths identified in the path discovery scan to a set of active paths for the host device. The per-host path change information received from the storage system may comprise a value of a path change counter maintained by the storage system for the host device.

Abstract: Determining an expected compression rate for a prospective process in a federated system includes obtaining compression rate data for existing processes in the federated system, compiling the compression rate data into a plurality of entries in a process name table according to process identifier, client, and industry, determining a specific entry in the process name table for an existing process that most closely matches the prospective process, and determining an expected compression rate of the prospective process based on the compression rate data for the specific entry. Compression rate data may be provided by a driver at host systems that sends compression rate information to a central repository. The central repository may be provided by a host system at a data center of the federated system. The compression rate data may use a sliding average that weighs the data more heavily to favor more recent data.

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: Described are techniques for processing I/O operations that may include: issuing, by a process of an application on a host, an I/O operation; tagging the I/O operation with a tag value in accordance with a process name associated with the process that issued the I/O operation; sending the I/O operation from the host to a data storage system; and determining, on the data storage system, an service level objective (SLO) for the I/O operation in accordance with the tag value of the I/O operation. The process name may include a first portion and a second customizable or configurable portion used to distinguish between different instance of the same application process. It may be determined which of multiple time-dependent SLOs for the process name is active and used with the I/O operation based on a receipt or processing time associated with the I/O operation.

Abstract: Embodiments are described for dynamically allocating and reallocating system resources between production work tasks and administrative tasks using policies. A resource monitor continuously monitors all resources in a computing system, and whether the resources are used for production work or administrative tasks. A policy can define resources needed to execute an administrative task and conditions which can be used to determine whether or not the administrative command is allocated the resources, even at the expense of a negative impact to production work.

Abstract: Execution of I/O operations for an application is managed to improve consistency of performance for an I/O performance metric for the application. Such control may be achieved by defining a value for a performance resilience objective (PRO) parameter, and applying the PRO value to I/O requests of the application. The PRO value may define a value indicative of an extent to which I/O performance can deviate from a performance objective (e.g., as defined by a service level) over time; i.e., a tolerance for such deviation. Components of a computer network may be configured to apply PRO values to I/O requests for one or more applications. The PRO values of applications may be distributed to one or more components of a data storage system and one or more components of a host system, and these components may be configured to apply the PRO values to I/O requests of the subject applications.

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 includes 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 particular ports of the storage system over the network in accordance with a load balancing algorithm. The multi-path input-output driver is further configured to receive notification from one or more of the ports indicating that at least a given one of the ports has exceeded a designated threshold level of port load, and to adjust the load balancing algorithm based at least in part on the received notification.

Abstract: A data storage system migrates a device between a storage array and a cloud gateway based on monitored conditions such as access frequency. More particularly, both a logical volume and the associated data are migrated. The unique device ID (e.g. and without limitation the WWN or WWID) is maintained after migration so the migration is transparent to the host application. The device is deleted from the migration source after being moved to the migration target, thereby releasing resources such as memory, storage, processor cycles and bandwidth at the migration source. A multi-path IO driver in the host computer coordinates with a tiering program in the storage array and a monitoring program in the cloud gateway to manage migration of the logical volume.

Abstract: Systems and methods for scheduling multiple flows in a computing system or for allocating resources to the flows in the computing system. Each flow may be associated with a target priority and a target performance. A current priority can be determined for each flow and resources are allocated based on the highest current priority. Over time, the current priorities change and each flow will receive resources as the flows are scheduled for execution. No flow is starved of resources.

Abstract: A cloud storage replica of a production device is created and asynchronously updated. A snap, clone or portion of the replica is copied to a cloud gateway in a failover situation. Access to replica images may be obtained via other cloud gateways.

Abstract: Embodiments are described for a multi-node file system, such as a clustered or distributed file system, with a file system buffer cache and an additional host-side tier non-volatile storage cache such as 3DXP storage. Cache coherency can be maintained by one of three models: (i) host-side tier management, (ii) file system management, or (iii) storage array management. performing a storage tier-specific file system action in a file system that comprises a namespace that spans multiple tiers of storage.

Abstract: Embodiments are described for a multi-node file system, such as a clustered or distributed file system, with a file system buffer cache and an additional host-side tier non-volatile storage cache such as 3DXP storage. Cache coherency can be maintained by one of three models: (i) host-side tier management, (ii) file system management, or (iii) storage array management. performing a storage tier-specific file system action in a file system that comprises a namespace that spans multiple tiers of storage.

Abstract: Example embodiments of the present invention relate to a method, an apparatus, and a computer program product for mirroring data in a data storage system across a first storage device having a first latency and a second storage device having a second latency. The method includes receiving an I/O at the data storage system and controlling the I/O to the first storage device having the first latency or the second storage device having the second latency according to properties of the I/O and properties of the first storage device having the first latency and the second storage device having the second latency.