Abstract: A method for more effectively distributing the I/O workload in a data replication system is disclosed herein. In selected embodiments, such a method may include generating an I/O request and identifying a storage resource group associated with the I/O request. In the event the I/O request is associated with a first storage resource group, the I/O request may be directed to a first storage device and a copy of the I/O request may be mirrored from the first storage device to a second storage device. Alternatively, in the event the I/O request is associated with a second storage resource group, the I/O request may be directed to a second storage device and a copy of the I/O request may be mirrored from the second storage device to the first storage device. A corresponding system, apparatus, and computer program product are also disclosed and claimed herein.

Abstract: Provided are a computer program product, system, and method for managing write operations to an extent of tracks migrated between storage device. An operation is processed to migrate an extent of tracks from the second storage to the first storage. A determination is made as to whether an extent object exists for the extent to migrate. The extent object exists if the extent was previously migrated from the first storage to the second storage at a previous time. The extent object includes for each track a write indicator indicating whether the track was updated in the second storage since the previous time when the extent was previously migrated to the second storage. In response to determining that the extent object exists, a determination is made of the tracks in the extent having the write indicator indicating that the track was updated in the second storage since the previous time. The data for the determined tracks is copied from the second storage to free locations in the first storage.

Abstract: Provided are techniques for migrating a first extent, determining a spatial distance between the first extent and a second extent, determining a ratio of a profiling score of the second extent to the spatial distance, and, in response to determining that the ratio exceeds a threshold, migrating the second extent.

Abstract: Provided are techniques for migrating a first extent, determining a spatial distance between the first extent and a second extent, determining a ratio of a profiling score of the second extent to the spatial distance, and, in response to determining that the ratio exceeds a threshold, migrating the second extent.

Abstract: Provided is a light projection structure (10), including: a reflective member (11) including a reflective surface (11a), the reflective surface (11a) being formed as a concave surface having a focal point (f) positioned near its apex (t); and a light emitting member (12) disposed at the focal point (f) and its vicinity, for emitting light when excited by excitation light.

Abstract: A storage system according to one embodiment includes logic adapted for determining to move an extent from a source-tier in a storage system to a destination-tier in the storage system, wherein a set of tracks of the extent is presently being accessed; logic adapted for determining whether any track from the set of tracks is presently being written to; logic adapted for designating to a write-stack associated with the source-tier each track that is presently being written to and designating to a read-stack associated with the source-tier remaining tracks from the set of tracks; logic adapted for removing oldest tracks from the read-stack and the write-stack until the read-stack and the write-stack have been depleted of tracks; logic adapted for populating a destination-tier cache with the tracks as they are removed from the read-stack and the write-stack using a predetermined read-to-write ratio when a parameter of the extent exceeds a migration threshold; logic adapted for removing any tracks from a source-t

Abstract: A method of operating an electronically controlled dual fuel compression ignition engine includes injecting a pilot ignition quantity of liquid fuel into an engine cylinder from a dual fuel injector in an engine cycle during an auto ignition condition. An amount of gaseous fuel is also injected into the engine cylinder from the dual fuel injector in the same engine cycle. The amount of gaseous fuel is divided between a pre-mix quantity of gaseous fuel, which may be injected about 90° before top dead center, and a post ignition quantity of gaseous fuel that may be injected after top dead center, with both quantities being greater than zero. An engine controller may change a ratio of the pre-mix quantity of gaseous fuel to the post ignition quantity of gaseous fuel responsive to changing from a first engine speed and load to a second engine speed and load. The pilot ignition quantity of liquid fuel is compression ignited, which in turn causes the gaseous fuel to be ignited.

Abstract: A method for more effectively distributing the I/O workload in a data replication system is disclosed herein. In selected embodiments, such a method may include generating an I/O request and identifying a storage resource group associated with the I/O request. In the event the I/O request is associated with a first storage resource group, the I/O request may be directed to a first storage device and a copy of the I/O request may be mirrored from the first storage device to a second storage device. Alternatively, in the event the I/O request is associated with a second storage resource group, the I/O request may be directed to a second storage device and a copy of the I/O request may be mirrored from the second storage device to the first storage device.

Abstract: A light projection unit capable of improving light use efficiency is provided. This light projection unit includes: a fluorescent member that includes an illuminated surface to which laser light is directed, converts at least part of the laser light into fluorescent light and outputs the fluorescent light from chiefly the illuminated surface; and a reflection member that includes a first reflection surface which reflects the fluorescent light output from the fluorescent member. The illuminated surface of the fluorescent member is inclined with respect to a predetermined direction in such a way that the illuminated surface faces in a direction opposite to a light projection direction.

Abstract: Provided are a computer program product, system, and method for managing write operations to an extent of tracks migrated from a second storage to a first storage. An extent object exists if the extent was previously migrated from the first storage to the second storage at a previous time. In response to determining that the extent object exists, a determination is made of the tracks in the extent having a write indicator indicating that the track was updated in the second storage since the previous time. The data for the determined tracks is copied from the second storage to free locations in the first storage. For each determined track, the entry for the determined track in the extent object is updated to indicate the free location to which the data for the track was copied as an active address for the track.

Abstract: Extent migration is provided in a data storage environment configured for synchronous replication between a primary and secondary pair of storage entities, each having tiered storage devices. In one embodiment, by way of example only, a migration instruction is sent, by the primary storage entity, to the secondary storage entity, the migration instruction including a relative priority based on a primary ordered heat map of the tiered storage devices of the primary storage entity. The relative priority is used against a secondary ordered heat map of the tiered storage devices of the secondary storage entity to perform the extent migration, regardless of whether the primary and secondary storage entities are identical.

Abstract: Extent migration is provided in a data storage environment configured for synchronous replication between a primary and secondary pair of storage entities, each having tiered storage devices. In one embodiment, by way of example only, a migration instruction is sent, by the primary storage entity, to the secondary storage entity, the migration instruction including a time delta approximately equal to a time of an intended migration at the primary storage entity adjusted for a transmission time such that the primary and secondary storage entities conduct the extent migration at approximately a same time.

Abstract: Provided are a method, system, and computer program product for using a migration cache to cache tracks during migration. In response to a migration operation, a determination is made of a first set of tracks in the source storage indicated in an extent list and of a second set of tracks in the extent. The tracks in the source storage in the first set are copied to a migration cache. The tracks in the second set are copied directly from the source storage to the destination storage without buffering in the migration cache. The tracks in the first set are copied from the migration cache to the destination storage. The migration operation is completed in response to copying the first set of tracks from the migration cache to the destination storage and copying the second set of tracks from the source storage to the destination storage.

Abstract: A method according to one embodiment includes determining to move an extent from a source-tier in a storage system to a destination-tier in the storage system; determining whether any track from the set of tracks is presently being written to; designating to a write-stack associated with the source-tier each track that is presently being written to and designating to a read-stack associated with the source-tier remaining tracks from the set of tracks; removing oldest tracks from the read-stack and the write-stack until the read-stack and the write-stack have been depleted of tracks; when a parameter of the extent exceeds a migration threshold: populating a destination-tier cache with the tracks as they are removed from the read-stack and the write-stack using a predetermined read-to-write ratio and removing tracks from a source-tier cache that were removed from the read-stack and the write-stack; and migrating the extent from the source-tier to the destination-tier.

Abstract: Provided are techniques for migrating a first extent, determining a spatial distance between the first extent and a second extent, determining a ratio of a profiling score of the second extent to the spatial distance, and, in response to determining that the ratio exceeds a threshold, migrating the second extent.

Abstract: A read/write ratio for each of a plurality of data segments classified in a hot category as hot data segments is determined. Each of the plurality of hot data segments is ordered by the read/write ratio in a descending order. Each of a plurality of available SSD devices is ordered by a remaining life expectancy in an ascending order. Those of the plurality of hot data segments are matched with those of the plurality of hot data segments with those of the plurality of available SSD devices such that a hot data segment having a higher read/write ratio is provided to an SSD device having a smaller remaining life expectancy than another hot data segment having a lower read/write ratio.

Abstract: In one embodiment, pursuant to migrating the data from the first to the second storage medium, the data is allocated to the second storage medium while retaining an allocation of the data in the first storage medium. If the data is migrated from the second storage medium back to the first storage medium, the data is pointed to the allocation of the data in the first storage medium to alleviate data movement from the second storage medium to the first storage medium. If the allocation of the data in the first storage medium is determined to be needed for other data, the allocation of the data in the first storage medium is freed.

Abstract: A method for migrating extents between extent pools in a tiered storage architecture maintains a data access profile for an extent over a period of time. Using the data access profile, the method generates an extent profile graph that predicts data access rates for the extent into the future. The slope of the extent profile graph is calculated and used to determine whether the extent will reach a migration threshold within a specified “look-ahead” time. If so, the method calculates a migration window that allows the extent to be migrated prior to reaching the migration threshold. In certain embodiments, the method determines the overall performance impact on the source extent pool and destination extent pool during the migration window. If the overall performance impact is below a designated impact threshold, the method migrates the extent during the migration window.

Abstract: A method for managing extents in a data storage system includes monitoring usage statistics for an extent residing on one or more powered-up storage devices. In the event the extent has not been accessed for specified period of time (as determined from the usage statistics), the method automatically compresses the extent and migrates the extent to an intermediate repository. Once the amount of data in the intermediate repository reaches a specified level, the method migrates the extent from the intermediate repository to one or more normally powered-down storage devices. If I/O is received for the extent while it resides in the normally powered-down storage devices or the intermediate repository, the method automatically migrates the extent from the normally powered-down storage devices or the intermediate repository to the normally powered-up storage devices. A corresponding apparatus and computer program product are also disclosed.

Abstract: An internal combustion engine includes a combustion chamber at least partially defined within a cylinder bore by a reciprocating piston having a piston crown. An intake plenum is fluidly connectable with the combustion chamber and at least one intake port is configured to fluidly connect the intake plenum with the combustion chamber. At least one intake valve is configured to selectively fluidly connect the intake plenum with the combustion chamber. The combustion chamber is configured to receive a lean air/fuel mixture therein to substantially fill the combustion chamber. The combustion chamber is further configured to receive a rich air/fuel mixture therein that yields a stratified total air/fuel mixture within the combustion chamber.