Servicing I/O operations directed to a dataset that is synchronized across a plurality of storage systems, including: receiving, by a follower storage system, a request to modify the dataset; sending, from the follower storage system to a leader storage system, a logical description of the modification to the dataset; receiving, from the leader storage system, information describing the modification to the dataset; processing, by the follower storage system, the request to modify the dataset; receiving, from the leader storage system, an indication that the leader storage system has processed the request to modify the dataset; and acknowledging, by the follower storage system, completion of the request to modify the dataset.

Systems and methods for garbage collection are disclosed. A garbage collection is triggered in a memory allocation based on a free list and selected amount of free space in an inner closed feedback loop. The free list is determined from a selected memory load and a current memory load as generated from the garbage collection in an outer outer feedback loop.

The present disclosure generally relates to data storage devices, such as solid state drives (SSDs), specifically utilizing the data storage device memory in the execution of host commands. A controller is configured to receive a command pointer or a data chunk from a host device, mark a destination used for the command pointer or the data chunk, determine whether a last chunk of the command pointer or the data chunk has been received, and determine whether the command pointer or the data chunk uses an illegal combination of locations after determining that the last chunk of the command pointer has been received. The controller is further configured to return an error message to the host device upon determining that the command pointer or the data chunk uses an illegal combination of locations.

A device and method for dispensing a friction-coefficient-optimizing mixture of at least one lubricant and at least one grit into the gap between a rail wheel of a rail vehicle and a rail. The device includes a reservoir for the lubricant, a reservoir for the grit, a metering unit for metering the lubricant, a metering unit for metering the grit, a delivery apparatus for delivering the lubricant, a delivery apparatus for delivering the grit, and a common dispensing nozzle. The apparatus for delivering the lubricant and the apparatus for delivering the grit are separate from each other and end in the common dispensing nozzle, the friction-coefficient-optimizing mixture therefore not being formed until the dispensing, and an additional compressed air line is provided, which ends in the common dispensing nozzle.

Automatic storage system configuration for mediation services that includes: determining that a particular storage system of the storage systems is not configured to request mediation from a mediation target for mediation between storage systems synchronously replicating a dataset; requesting, by the particular storage system from a configuration service, configuration information indicating one or more service handles for a mediation service; and configuring, in dependence upon the one or more service handles received from the configuration service, a mediation handler to communicate with the mediation service responsive to detecting a communication fault with one of the storage systems.

Various systems and methods for controlling memory traffic flow rate are described herein. A system for computer memory management, the system comprising: rate control circuitry to: receive a rate exceeded signal from monitoring circuitry, the rate exceeded signal indicating that memory traffic flow from a traffic source exceeds a threshold; receive a distress signal from a memory controller that interfaces with a memory device, the distress signal indicating that the memory device is oversubscribed; and implement throttle circuitry to throttle the memory traffic flow from the traffic source when the rate exceeded signal and the distress signal are both asserted.

Methods and systems for estimating a number of entries in a dispersed hierarchical index. The method and systems involve determining a number of random walks N to perform on the dispersed hierarchical index, conducting N walkthroughs based on the number of walkthroughs, determining a number of walk entries for each of the N random walks and averaging the number of walk entries for each of the N random walks to produce an estimated total number of entries for the dispersed hierarchical index. The determining may be based on one or more of a number of levels, a desired confidence interval, a predetermination, and interpretation of system registry information, and an interpretation of a request. Each random walk starts at a root node and ends at a leaf node through L levels of the dispersed hierarchical index.

Provided are a computer program product, integrated cache manager, and method for maintaining data in a first level memory and buckets representing regions of memory devices to extend data cache. A plurality of buckets represent distinct regions of memory devices. The buckets are associated with different threshold access count ranges. Data having an access count is stored in one of the buckets associated with a threshold access count range including the access count of the data to store. Data evicted from a first level memory is copied to an initial bucket comprising one of the buckets. Data is moved from a source bucket comprising one of the buckets, including the initial bucket, to a target bucket of the buckets having a target threshold access count range including an access count of the data to move.

Establishing a synchronous replication relationship between two or more storage systems, including: identifying, for a dataset, a plurality of storage systems across which the dataset will be synchronously replicated; configuring one or more data communications links between each of the plurality of storage systems to be used for synchronously replicating the dataset; exchanging, between the plurality of storage systems, timing information for at least one of the plurality of storage systems; and establishing, in dependence upon the timing information for at least one of the plurality of storage systems, a synchronous replication lease, the synchronous replication lease identifying a period of time during which the synchronous replication relationship is valid.

An apparatus, system, method, and program product for verifying a communication bus connection to a peripheral device are disclosed. The apparatus includes a data module that receives, over a communication bus, an identifier for a location where a peripheral device is installed. The peripheral device is communicatively coupled to an information handling device using the communication bus. The apparatus includes a verification module that compares the identifier received over the communication bus to a predefined identifier associated with the communication bus. The apparatus includes a notification module that sends a notification in response to the identifier received over the communication bus not matching the predefined identifier associated with the communication bus.