Abstract: A system and method for thresholding system power loss notifications in a data processing system are provided. Power loss detection modules are provided in a data processing system having one or more data processing devices, such as blades in an IBM BladeCenter® chassis. The power loss detection modules detect the type of infrastructure of the data processing system, a position of a corresponding data processing device within the data processing system, and a capability of the data processing system to provide power during a power loss scenario. The detection module detects various inputs identifying these types of data processing system and power system characteristics and provides logic for defining a set of behaviors during a power loss scenario, e.g., behaviors for sending system notifications of imminent power loss. The detection of the various inputs and the defining of a set of behaviors may be performed statically and/or dynamically.

Abstract: Provided are a method, system, and article of manufacture, wherein a determination is made that a first data array in a plurality of data arrays has to be repaired to replace a failed storage device within the first data array. A storage device is selected from a selected data array of the plurality of data arrays to replace the failed storage device, wherein a data value corresponding to the selected data array is less than the data value corresponding to the first data array.

Abstract: Provided are a method, system, and article of manufacture, wherein a plurality of data arrays coupled to a storage controller is maintained. Data arrays are selected from the plurality of data arrays based on predetermined selection rules. Data is stored redundantly in the selected data arrays by writing the data to the selected data arrays.

Abstract: A data storage enclosure management system of a plurality of service processors is configured to communicate externally via a pair of FC-AL loops. Lead and subsidiary service processors are defined and lead service processors connect to ones of the FC-AL loops with an FC-AL address, and the lead and subsidiary service processors are connected by a secondary communication link. The lead service processor(s) employ an identifier unassociated with the FC-AL address to differentiate communications of the lead service processor from communications of an associated subsidiary service processor, the lead service processor serving as a proxy for the associated subsidiary service processor with respect to the FC-AL address and communicating with the associated subsidiary service processor via the secondary communication link.

Abstract: Provided are techniques for processing read and write request operations. Regions of a first storage device and a second storage device are designated as primary regions and secondary regions for read request operations and write request operations falling within the regions. At least one write request operation is processed. Upon determining that a write threshold has been reached, the designations of regions of the first storage device and the second storage device are switched.

Abstract: An apparatus, system, and method are disclosed for selective cross communications between autonomous storage modules. A RAID controller communicates through a first cascading communications loop comprising a first storage module. The first storage module includes a plurality of storage devices and is disposed in an enclosure. The RAID controller also communicates through a second cascading communications loop comprising a second storage module. The second storage module also includes a plurality of storage devices and is disposed in the enclosure. An interface module transmits messages of the first loop through the second storage module. In one embodiment, the RAID controller communicates a cross communications command to the interface module through the second storage module to enable the interface module to transmit the messages of the first loop through the second storage module in response to a failure of the first loop upstream of the first storage module.

Abstract: An apparatus, system, and method are disclosed for providing a redundant array of inexpensive disks (“RAID”) storage subsystem within a processor blade enclosure. A first RAID controller blade is included and configured to fit in a processor blade enclosure. At least one processor in communication with the first RAID controller blade is included. A disk enclosure blade is provided that includes a plurality of hard disk drives. The disk enclosure blade is configured to fit in the processor blade enclosure and the hard disk drives are in communication with the first RAID controller blade.

Abstract: A radio frequency identifier (RFID) active/passive tag is provided to identify failed sub-CRU and location within a higher level CRU. When an error occurs on the base blade or within one of the sub-CRUs, the embedded processor writes failure information to the RFID. RFID tags may also contain data identifying the locations, of the sub-CRUs of the blade. Thus, when there is a failure, the RFID may report the failed component as well as the location of a failed sub-CRU. Sub-CRUs may also include an embedded processor and RFID tag. When a service action is initiated to repair or replace a blade, the RFID tag may be read by a RFID reader. The RFID reader device may then present failure information, including the identification of the failed sub-CRU and other associated information to the operator. The RFID reader device may also request associated information from a server computer.

Abstract: A sector conversion device includes a small memory area that is used to save two sector's worth of data when power is lost during the sector conversion process. As part of the sector conversion process, the sector conversion device saves two sectors of data when a power loss event occurs. These two sectors of data are stored in the memory area within the sector conversion device itself. This sector memory within the sector conversion device is defined and partitioned separately from the main internal memory of the device. This sector memory is also powered by a separate voltage boundary from a hold up voltage source, which is connected to the sector conversion device via an independent set of voltage pins. The hold up voltage source enables the sector memory contents to be retained.

Abstract: An apparatus, system, and method are disclosed for preventing write starvation in a storage controller with access to low performance storage devices. A storage device allocation module is included to assign a storage device write cache limit for each storage device accessible to a storage controller. The storage device write cache limit comprises a maximum amount of write cache of the storage controller available to a storage device for a write operation. At least one storage device comprises a low performance storage device and a total amount of storage available to the storage devices comprises an amount greater than a total storage capacity of the write cache. A low performance write cache limit module is included to set a low performance write cache limit. The low performance write cache limit comprises an amount of write cache available for use by the at least one low performance storage device for a write operation.

Abstract: Provided are a method, system, and article of manufacture for relocating a logical volume from a first storage location to a second storage location using a copy relationship. An operation is initiated to move a logical volume from a first storage location to a second storage location. A relationship is established between the first and second storage locations to copy data in the logical volume from the first storage location to the second storage location. A read request is received to data in the logical volume while copying the data in the logical volume from the first storage location to the second storage location. A determination is made, in response to the read request, whether the requested data is at a first copy of the logical volume in the first storage location or a second copy of the logical volume as the second storage location.

Abstract: An apparatus, system, and method are disclosed for limiting failures in redundant signals. A coordination module generates a power status signal for each of a plurality of power modules. An input module receives a source signal. A signal generation module generates a plurality of output signals from the source signal and at least one power status signal. The output signals are not asserted if at least one power supply is operational. If a device of the signal generation module malfunctions, no more than one output signal is erroneously asserted.

Abstract: A mechanism is provided for unique identification of each endpoint in a storage area network interconnect that is bridged by a specialized cable. Each endpoint is capable of querying peer endpoints for a unique identification. Once a unique identifier is obtained for all peer connections to a given endpoint, the endpoint may perform a comparison to validate that the cable connection terminations are connected to valid endpoints. If all endpoints are valid, then the mechanism enables the ports connected to the cable.

Abstract: An apparatus, system, and method are disclosed for maximizing power system holdup time during loss of input power. An energy storage module is included to deliver energy from an output stage of a first power supply to a bus. A power loss module is included to detect loss of power transmitting capability from an input stage of the first power supply to the output stage of the first power supply. A set-point reduction module is included to reduce an output voltage of the first power supply in response to the power loss module detecting loss of power transmitting capability. An isolation module is included to prevent energy flow from the energy storage module to the bus when the output voltage of the first power supply is lower than a voltage on the bus sustained by a second power supply.

Abstract: Provided are a method, system, and article of manufacture for updating metadata in a logical volume associated with a storage controller. A data structure is generated indicating data units in a volume whose metadata is to be updated. An operation is initiated to update the metadata for data units indicated in the data structure. Indication is made in the data structure that the metadata for one data unit has been updated in response to updating the metadata for the data unit. An Input/Output (I/O) request is received to one data unit in the volume while the metadata for the data units indicated in the data structure is being updated. A determination is made, in response to the I/O request, from the data structure whether the metadata for the requested data unit was updated. The metadata for the requested data unit is updated in response to determining that the metadata for the requested data unit has not been updated. The I/O request is executed against the requested data unit.

Abstract: An apparatus, system, and method are disclosed for presenting a storage volume as a virtual volume. An attribute module determines a primary volume physical attribute of a primary volume. A presentation module presents the primary volume physical attribute to a host as a target volume virtual attribute of a target volume. A translation module translates communications between a host and the target volume. In one embodiment, a copy module creates a point-in-time copy of the primary volume on the target volume.

Abstract: An apparatus, system, and method are disclosed for securely providing power supply commands. A security feature is added to the remote management of power-on and power-off sequences. The feature allows for multiple controller nodes to receive a command to initiate a power sequence. Each controller node possesses a unique identifier. The nodes compare the received command with received commands of other nodes to confirm that each node received identical power commands. The security feature prevents inadvertent power commands from being received and executed by a single controller node. The unique identifier of each node must be provided before execution of the power command occurs.

Abstract: Provided are a method, system, and article of manufacture, wherein a request is received for switching a logical volume from one state to another state, wherein the logical volume is in a mirrored state if data corresponding to the logical volume is mirrored from a first storage to a second storage, and wherein the logical volume is in a non-mirrored state if the data corresponding to the logical volume is not mirrored from the first storage to the second storage. A determination is made as to whether to perform the switching, in response to receiving the request.

Abstract: The method forms a plurality of DMA data payloads each comprising a plurality of first sectors, and sends to a sector format conversion device one or more of those DMA data payloads. The method then overlays the (i)th DMA data payload onto part or all of a plurality of second sectors to form the (i)th converted DMA data payload, enqueues that (i)th converted DMA data payload in a data queue, transmits that (i)th converted DMA data payload to a data storage device, and writes the (i)th converted DMA data payload to an information storage medium.