Abstract: Methods, systems, computer program products and methods for deploying computing infrastructure for managing metadata in a storage subsystem are provided. A call is received from a client to update a portion of a metadata track. Data is also received from the client identifying at least one field of the metadata track to be updated, associated update values for the at least one field to be updated and an update type for the at least one field. A data structure field of a client interface is then populated with the identity of the at least one field and the associated update values and an opcode field of the client interface is populated with the update type. A task control block (TCB) is then allocated to the client call and, at the direction of the TCB, various operations are performed without further activity by the client. The metadata track may also be validated before being updated to ensure that the client has access only to valid updates.

Abstract: Methods, systems, computer program products and methods for deploying computing infrastructure for clearing metadata in a storage subsystem. The method includes identifying one or more metadata tracks to clear, receiving a request from a client to clear the identified tracks, quiescing any active processes, clearing the identified tracks and resuming the quiesced processes. The request may be a single request operable to clear all metadata tracks. Alternatively, target volumes having metadata tracks to be cleared are identified and a request is received from a client for each target volume. A dynamic function list may also be created for each target volume, the list including a list of functions in which the target volume is associated. After active processes are quiesced, each function in the dynamic function list of each target volume is invoked whereby the metadata tracks are cleared. The quiesced processes are then resumed.

Abstract: Methods, systems, computer program products and methods for deploying computing infrastructure for managing metadata in a storage subsystem are provided. A first metadata track is staged from disk storage to a cache storage after which a journal entry is stored in a nonvolatile storage (NVS). The journal entry includes an opcode and update data for the track. The opcode identifies the type of update to be performed and the number of tracks to be updated in the operation. Each of the other metadata tracks is staged and a corresponding journal entry stored. The journaled updates are then applied to the respective metadata track in the cache storage and the tracks destaged from cache to the disk storage.

Abstract: A device for sealing between a first component and a second component is disclosed. The first component has a groove and the groove has a first wall and a second wall. The annular body includes a first side configured to selectively contact the first wall of the groove, a second side opposite the first side configured to selectively contact the second wall of the groove, a first surface in contact with the second component, and a second surface opposite the first surface. A lip is bonded to the second surface and extends at least partially around the second surface of the annular body. A pressure acting on the first side of the annular body forces the second side to contact the second wall of the groove, and a pressure acting on the second side of the annular body forces the first side to contact the first wall of the groove.

Abstract: A vibration damper apparatus has two substantially freely rotatable inertia members disposed within a rotatable hub. Each of the members has a wide semi-cylindrical portion and a narrow semi-cylindrical portion with the wide portion of the first damper member being axially aligned with the narrow portion of the other damper member.

Abstract: Tracks of meta data are cleared in a storage server by allocating task control blocks for executing associated tasks in parallel. Throttling and recycling of task control blocks is provided to efficiently use memory and processing resources. Under the control of a master task, task control blocks are allocated to different hierarchical levels of storage resources in the storage server, such as a logical subsystem level and a subordinate volume level. The task control blocks are not deallocated from memory until there are no further tasks to process.

Abstract: A system is employed to maintain persistent operation information for implementation on persistent data. Bitmaps are created to track outstanding persistent operations. Should a volume of information became inaccessible, the bitmaps are evaluated to determine if outstanding persistent operations exist and, if so, these outstanding operations are performed before the volume is integrated into the logical memory space. Additionally, operation-in-progress bitmaps are utilized to indicate that persistent data within a volume is being modified.

Abstract: A hydraulic fluid storage apparatus for a transmission has a main sump and a secondary sump. The secondary sump is connected with the main sump through a restricted flow passage. The fluid within the main sump is subjected to centrifugal forces by rotating components within the transmission, such that at high speeds and high levels in the main sump, the restricted passage is closed by a centrifugal dam thereby resulting in fluid storage within the secondary sump. The fluid storage in the secondary sump returning to the main sump when the speed of the rotating components is reduced.

Abstract: A clutch assembly includes a hub with a hub friction surface and an inner surface that cooperate to define a cavity. A damper member is situated within the cavity and is in contact with the hub friction surface. The damper member is rotatable with respect to the hub so that relative movement between the damper ring and the hub friction surface results in energy absorption and dissipation to minimize unwanted clutch vibration. The damper ring is located inside the clutch hub so that it does not adversely affect transmission packaging. The clutch assembly preferably includes a member configured to direct lubricant along an inner diameter of the damper member so that it subsequently flows between the damper ring and the hub friction surface and through holes in the hub to lubricate clutch plates.

Abstract: A data storage control unit is coupled to one or more host devices and to one or more physical storage units. Data is stored in one of the storage units and, for data integrity, copied to another storage unit. An updated state of the copy process (metadata) is maintained and updated in metadata tracks in a memory of the storage controller and periodically destaged to corresponding metadata tracks of a storage unit. If the copy process is interrupted, such as by a power failure, an error handling routine commences. Track state fields associated with each in-memory metadata track are initialized to an ‘invalid’ state and background staging of metadata tracks from the storage unit to the memory. After a track is staged, the associated track state field is changed to a ‘valid’ state. If a request is received to access a track of copy state data and the track has been staged (as indicated by the state of the associated track state field), the track is accessed.

Abstract: A thrust bearing having an integral axially oriented resilient means provides a gap between unloaded thrust surfaces. The gap is sufficiently large to prevent bearing rollers from contacting both thrust surfaces simultaneously. Providing such a gap reduces noise from unloaded thrust bearings.