Abstract: Cluster management logic in a storage appliance of a storage cluster receives messages that are automatically transmitted periodically by unconfigured storage appliances. The unconfigured storage appliances do not belong to the storage cluster, and the messages contain properties of the unconfigured storage appliances. The messages may be multicast DNS (Domain Name Service) messages. The cluster management logic determines a level of compatibility of each one of the unconfigured storage appliances with regard to the storage cluster, based on the received properties. Determining the level of compatibility of each unconfigured storage appliance with the storage cluster may include assigning one of multiple compatibility level categories to each unconfigured storage appliance.

Abstract: Various systems and methods are presented herein regarding controlling operation of central processing units (CPUs) to reduce power consumption at a data center(s). A first subset of CPUs located on a computer system can be operationally adjusted while a second subset of CPUs can be designated as having to be available at all times with a default operating condition (e.g., to run background operations). As operational demand placed on the computer system reduces, operation of the first subset of CPUs can be throttled back (e.g., clock speed reduced) while the second subset of CPUs remain at the default operating condition. As operational demand subsequently increases respective CPUs in the first subset of CPUs can have their operating condition (e.g., clock speed) increased. By adjusting the operating condition of one or more CPUs, power consumption at the data center can be reduced during periods of low operational demand.

Abstract: In at least one embodiment, processing can include: sending, from a host to a data storage system, a first storage reclamation command that identifies a first storage region of physical storage available for reclamation and reuse; in response to the data storage system receiving the first storage reclamation command, sending from the data storage system to the host first feedback information identifying at least a first detected condition on the data storage system; and in response to receiving the first feedback information at the host, the host varying a current rate or frequency of subsequent storage reclamation commands sent to the data storage system based, at least in part, on the first feedback information regarding the first detected condition on the data storage system.

Abstract: A method, computer program product, and computing system for synchronizing system software between a new storage appliance and a storage cluster having one or more pre-existing appliances. The synchronization process includes: determining a software version used by the pre-existing storage appliances in the storage cluster, determining a software version used by the new storage appliance to be added to the storage cluster, and comparing the software version used by the pre-existing storage appliances to the software version used by the new storage appliance. Moreover, in response to determining that the software version used by the new storage appliance is more recent than the software version used by the pre-existing storage appliances, the synchronization process performs a hardware check on the new storage appliance for hardware compatibility with the software version used by the pre-existing storage appliances.

Abstract: A power controller for a data storage system automatically selects different power modes based on changing forecasts of availability of renewable energy. The power modes indicate settings for each of a plurality of hardware resources, such as processors, fans, memory, and drives. At times when the storage system can operate at less than the maximum level of performance in terms of IO latency or IOPS, power consumption of one or more of the hardware resources is reduced to a degree corresponding to availability of renewable energy. For example, the hardware resources may be operated in a relatively higher power mode when renewable energy is available than when renewable energy is unavailable. The storage system may be configured to automatically implement a low power mode when power from all sources is in limited supply, e.g., during a brownout.

Abstract: A method, computer program product, and computing system for determining a recovery point object (RPO) value for a storage object. An amount of data to transfer from the storage object to a disaster recovery site is determined. A data replication transfer schedule for the storage object is generated based upon, at least in part, the RPO value and the amount of data to transfer. Data is asynchronously transferred from the storage object to the disaster recovery site using the data replication transfer schedule.

Abstract: A data storage system is operated for reduced power consumption, including regularly scanning usage patterns of data stored on a set of production storage devices to identify cold data whose usage is below a predetermined usage threshold, and adding the cold data of each scan to a collection of cold data. The production storage devices are operated in a normal power mode having normal per-device power consumption. Upon the collection of cold data reaching a predetermined size, (1) one of the production storage devices is designated as a green tier device, and (2) the collection of cold data is moved to the green tier device. The green tier device is operated in a low power mode having a lower per-device power consumption to realize energy savings.

Abstract: Techniques are disclosed for network attached storage (NAS) server placement in a heterogeneous storage cluster. An example system includes at least one processing device including a processor coupled to a memory. The at least one processing device can be configured to implement the following steps: identifying a placement event associated with a NAS asset in a heterogeneous storage cluster, where the NAS asset is located on an initial appliance in the cluster, obtaining resource characteristics associated with the NAS asset, analyzing the resource characteristics to identify an available appliance in the cluster, and deploying the NAS asset to the identified appliance.

Abstract: Techniques are disclosed for storage resource resynchronization using pending IO requests.

Abstract: A distributed data storage system includes clusters of data storage appliances interconnected by an inter-cluster (IC) network having an IC namespace. Storage processing (SP) nodes exchange management traffic using mesh network (MN) addresses of a separate MN namespace. Gateways provide IC tunnels for routing management traffic among the clusters using IC network addresses. Operation includes, in each gateway for traffic from a local SP node destined for a remote SP node of another cluster, (1) performing a routing check based on a routing rule associating an MN destination address with a dummy MN address further associated with a respective IC tunnel, (2) applying a tunnel configuration rule of the IC tunnel associating the MN destination address with the IC network address of a remote gateway for the remote SP, and (3) forwarding the traffic on the respective IC tunnel using the IC network address of the remote gateway.

Abstract: Techniques can include: establishing a synchronous replication configuration for a group of stretched resources configured for bi-directional synchronous replication between a first site and a second site; and performing processing to implement a change or modification operation of the group of one or more existing stretched resources. The processing can include performing a three phase workflow comprising: a preparation phase that prepares the group for the change or modification operation of the group; a commitment phase that commits the change or modification operation to the group; and a synchronization phase that synchronizes content of the group in accordance with the change or modification operation to the group. Each stretched resource of the group can be configured from local resources of the first and second sites where such local resources have the same identity when exposed to an external host over paths from the first and second sites.

Abstract: A power controller for a data storage system automatically selects different power modes based on changing forecasts of availability of renewable energy. The power modes indicate settings for each of a plurality of hardware resources, such as processors, fans, memory, and drives. At times when the storage system can operate at less than the maximum level of performance in terms of IO latency or IOPS, power consumption of one or more of the hardware resources is reduced to a degree corresponding to availability of renewable energy. For example, the hardware resources may be operated in a relatively higher power mode when renewable energy is available than when renewable energy is unavailable. The storage system may be configured to automatically implement a low power mode when power from all sources is in limited supply, e.g., during a brownout.

Abstract: Techniques for dynamically configuring a multi-site storage system such as a metro cluster using input/output (IO) response time (RT) hints from a host computer. The techniques include receiving IO RT hints at each storage appliance of the multi-site storage system from the host computer, which is initially identified as “local” or “remote” relative to a physical location of the storage appliance. The techniques further include modifying, by the storage appliance, an initial local or remote identification of the host computer relative to the physical location of the storage appliance based on the received IO RT hints, dynamically changing, by the storage appliance, states of IO paths between the host computer and nodes of the storage appliance based on the modified local or remote identification of the host computer, and providing, by the storage appliance, notification of the changed states of the IO paths to the host computer.

Abstract: Techniques providing data path strategies for improving storage performance at DR sites. The techniques include receiving, in an asynchronous replication process, a large replication data transfer including data changes of a production volume since the last synchronization to a replica volume, partitioning the replication data into multiple small write requests, tagging each small write request as a write request to the replica volume, and performing early evicting, from cache memory, all cache pages used to cache host data specified in the small write requests; deep compression of contiguous host data specified in the small write requests; stream separation on the small write requests, each small write request being tagged as corresponding to a specific production site; and/or flushing host data having the same retention period to a specific region of physical storage space for the replica volume, each small write request being tagged with hint information indicating the retention period.

Abstract: Techniques can include: establishing synchronous replication configurations between first and second sites for a group of stretched resources and a stretched resource; and performing processing that adds the stretched resource to the group. While both the group and stretched resource are in an active-active state and replicating data, existing replication session objects associated with stretched resource on both sites can be deleted while retaining remaining portions of layered services stacks corresponding to the stretched resource on both sites. A first remaining portion can be added to a first replication session object corresponding to the group on the first site. A second remaining portion can be added to a second replication session object corresponding to the group on the second site. Even though the existing replication session objects associated with the stretched resource may be deleted, the existing configuration corresponding to the stretched object can be retained.

Abstract: In at least one embodiment, a method can include: establishing a bi-directional synchronous replication configuration for a stretched resource configured across first and second sites; determining a first difference between a first maximum normalized total I/O workload of the first site and a first current normalized total I/O workload of the first site without including read I/O workload of the stretched resource; determining a second difference between a second maximum normalized total I/O workload of the second site and a second current normalized total I/O workload of the second site without including read I/O workload of the stretched resource; and selecting, in accordance with the first difference and the second difference, only one of the first site and the second site to receive and service subsequent read and write I/Os directed to the stretched resource. The configuration can be equidistant with respect to a host and the stretched resource.

Abstract: Techniques can include: configuring source sites in a replication configuration with a target site; receiving, at a first of the source sites from a host, a write I/O to a target location of a source storage object of the source site; sending a replicated write corresponding to the write I/O from the first source site to the target site, wherein the replicated write writes to the target location of a target storage object of the target site; prioritizing the replicated write, based at least in part, on a site-level priority associated with the first source site; placing the first replicated write in a first queue of a first plurality of queues based, at least in part, on the site level priority associated with the first source site; selecting the first replicated write from said first queue; and servicing the first replicated write.

Abstract: Techniques can include: configuring source sites in a replication configuration with a target site; receiving, at a first of the source sites from a host, a write I/O to a target location of a source storage object of the source site; sending a replicated write corresponding to the write I/O from the first source site to the target site, wherein the replicated write writes to the target location of a target storage object of the target site; prioritizing the replicated write, based at least in part, on a site-level priority associated with the first source site; placing the first replicated write in a first queue of a first plurality of queues based, at least in part, on the site level priority associated with the first source site; selecting the first replicated write from said first queue; and servicing the first replicated write.

Abstract: Techniques can include: establishing a synchronous replication configuration for a group of stretched resources configured for bi-directional synchronous replication between a first site and a second site; and performing processing to implement a change or modification operation of the group of one or more existing stretched resources. The processing can include performing a three phase workflow comprising: a preparation phase that prepares the group for the change or modification operation of the group; a commitment phase that commits the change or modification operation to the group; and a synchronization phase that synchronizes content of the group in accordance with the change or modification operation to the group. Each stretched resource of the group can be configured from local resources of the first and second sites where such local resources have the same identity when exposed to an external host over paths from the first and second sites.

Abstract: Techniques for resynchronizing storage resources of two sites configured for synchronous replication can include tracking in-progress write requests in a map. Responsive to a site failure or a replication link failure resulting in failure or fracture of the synchronous replication, processing can be performed to resynchronize impacted resources of the two sites configured for synchronous replication. The processing can use the in-progress write requests in combination with resource snapshots and snapshot differences to resynchronize the impacted resource of the two sites. In at least one embodiment, the synchronous replication configuration can include active paths between both sites and a host. In at least one embodiment, the synchronous replication configuration can include an active path between the host and one site, and a passive path between the host and the second site. The synchronous replication can be bi-directional or two-way synchronous replication between the two sites.