Abstract: A battery backup system includes a control device including a power sensing device, a discharge circuit, a charging circuit, and a plurality of battery packs. A lower threshold is established representative of a minimum acceptable effective energy capacity. Each battery pack is recharged if its effective energy capacity falls below the lower threshold. Additionally, an upper threshold is established representative of the minimum acceptable effective energy capacity plus a performance margin. In a two battery-pack system, if both battery packs fall below the upper threshold, the battery with the least effective energy capacity is discharged to the minimum acceptable effective energy capacity and then recharged to the battery pack's maximum energy capacity. In this way, both battery packs are prevented from approaching the minimum acceptable effective energy capacity at the same time. This reduces the size or number of battery packs and reduces their associated cost and volume.

Abstract: A battery backup system includes a control device including a power sensing device, a discharge circuit, a charging circuit, and a plurality of battery packs. A lower threshold is established representative of a minimum acceptable effective energy capacity. Each battery pack is recharged if its effective energy capacity falls below the lower threshold. Additionally, an upper threshold is established representative of the minimum acceptable effective energy capacity plus a performance margin. In a two battery-pack system, if both battery packs fall below the upper threshold, the battery with the least effective energy capacity is discharged to the minimum acceptable effective energy capacity and then recharged to the battery pack's maximum energy capacity. In this way, both battery packs are prevented from approaching the minimum acceptable effective energy capacity at the same time. This reduces the size or number of battery packs and reduces their associated cost and volume.

Abstract: A self-contained backup power source such as a battery is provided for components within an electrically powered device such as a storage controller, photocopier or the like, to maintain diagnostic status data and to power a service indicator aid, or diagnostic indicator, such as an LED. A switch selects the backup power source when a primary power source of the electrically powered device is no longer available to the component, such as when the component is removed from the electrically powered device, the primary power source is disconnected as a safety precaution when servicing or replacing the component, or a higher-level assembly, in which the component is provided, is removed from the electrically powered device. The diagnostic indicator may be powered separately from the data storage device.

Abstract: A data storage and retrieval system that comprises a data storage device is disclosed. The data storage and retrieval system further comprises a first LED, a second LED, a third LED, and a fourth LED, interconnected with the data storage device. The data storage device causes the first LED and the second LED to emit first light comprising a first color if the data storage device detects an internal failure. Alternatively, the storage device causes the third LED and the fourth LED to emit second light comprising a second color if the data storage device remains operative.

Abstract: A method is disclosed to set the signaling rate of a switch domain disposed in an information storage and retrieval system. The method establishes a switch domain target operating speed, and determines if that switch domain target operating speed comprises a first signaling rate. If the switch domain target operating speed comprises a first signaling rate, then the method asserts first Device Control Code bits to each of the plurality of data storage devices, and each of the plurality of data storage devices communicates with the switch using that first signaling rate. If the switch domain target operating speed does not comprise the first signaling rate, then the method asserts second Device Control Code bits to each of the plurality of data storage devices, and each of the plurality of data storage devices communicates with the switch using a second signaling rate.

Abstract: A method to supply power to one or more battery-backup assemblies, wherein the method supplies a first controller, a second controller, a first battery-backup assembly, and a second battery-backup assembly. The method further supplies a power bus interconnected to the first controller, the second controller, the first battery-backup assembly, and the second battery-backup assembly, and a first power supply and a second power supply interconnected with the power bus. The method provides power to the first controller and to the second controller and to the first battery-backup assembly over a first period of time, and provides power to the first controller and to the second controller and to the second battery-backup assembly over a second period of time, where the first period of time differs from the second period of time.

Abstract: An apparatus and program storage device for maintaining data is provided that includes receiving primary data at a first node, receiving mirrored data from a second and third node at the first node, and mirroring data received at the first node to a second and third node.

Abstract: Method, system and computer program product are provided for detecting and correcting dropped writes in a storage system. Data and a checksum are written to a storage device, such as a RAID array. The state of the data is classified as being in a “new data, unconfirmed” state. The state of written data is periodically checked, such as with a timer. If the data is in the “new data, unconfirmed” state, it is checked for a dropped write. If a dropped write has occurred, the state of the data is changed to a “single dropped write confirmed” state and the dropped write error is preferably corrected. If no dropped write is detected, the state is changed to a “confirmed good” state. If the data was updated through a read-modified-write prior to being checked for a dropped write event, its state is changed to an “unquantifiable” state.

Abstract: Methods are provided for detecting and correcting dropped writes in a storage system. Data and a checksum are written to a storage device, such as a RAID array. The state of the data is classified as being in a “new data, unconfirmed” state. The state of written data is periodically checked, such as with a timer. If the data is in the “new data, unconfirmed” state, it is checked for a dropped write. If a dropped write has occurred, the state of the data is changed to a “single dropped write confirmed” state and the dropped write error is preferably corrected. If no dropped write is detected, the state is, changed to a “confirmed good” state. If the data was updated through a read-modified-write prior to being checked for a dropped write event, its state is changed to an “unquantifiable” state.

Abstract: A data storage and retrieval system that comprises a data storage device is disclosed. The data storage and retrieval system further comprises a first LED, a second LED, a third LED, and a fourth LED, interconnected with the data storage device. The data storage device causes the first LED and the second LED to emit first light comprising a first color if the data storage device detects an internal failure. Alternatively, the storage device causes the third LED and the fourth LED to emit second light comprising a second color if the data storage device remains operative.

Abstract: A method for maintaining data is provided that includes receiving primary data at a first node, receiving mirrored data from a second and third node at the first node, and mirroring data received at the first node to a second and third node.

Abstract: An apparatus and method to check integrity when handling data. The method provides a storage array which includes a plurality of sectors. The method defines (N) data state identifiers and (N) parity state identifiers. The method receives a command to handle data, where that command designates a target sector. The method determines the data state identifier assigned to the target sector, determines the parity state identifier assigned to the target sector, and compares the data state identifier and the parity state identifier. If the method determines that the data state identifier and the parity state identifier are the same, the method performs the command to handle data. Alternatively, if the method determines that the data state identifier and the parity state identifier differ, the method generates an error message.

Abstract: A method is disclosed to supply power to one or more battery-backup assemblies. The method supplies a first controller, a second controller, a first battery-backup assembly, and a second battery-backup assembly. The method further supplies a power bus interconnected to the first controller, the second controller, the first battery-backup assembly, and the second battery-backup assembly, and a first power supply and a second power supply interconnected with the power bus. The method provides power to the first controller and to the second controller and to the first battery-backup assembly over a first period of time, and provides power to the first controller and to the second controller and to the second battery-backup assembly over a second period of time, where the first period of time differs from the second period of time.

Abstract: A method is disclosed to set the speed of a network. The method supplies a network interconnected with a system controller and a plurality of switch domains, where each of those plurality of switch domains comprises one or more information storage devices and a switch domain controller, and sets by each of the plurality of switch domains a signaling rate for that switch domain. The method queries in-band by the system controller each of the plurality of switch domains for that switch domain's signaling rate, and provides in-band by each of the plurality of switch domains the signaling rate for that switch domain. The method provides in-band by the system controller to each of the plurality of switch domains a first speed selection command specifying a first network speed, and resets by each of the plurality of switch domains the signaling rate for that switch domain to the first network speed.

Abstract: An apparatus and method to check integrity when handling data. The method provides a storage array which includes a plurality of sectors. The method defines (N) data state identifiers and (N) parity state identifiers. The method receives a command to handle data, where that command designates a target sector. The method determines the data state identifier assigned to the target sector, determines the parity state identifier assigned to the target sector, and compares the data state identifier and the parity state identifier. If the method determines that the data state identifier and the parity state identifier are the same, the method performs the command to handle data. Alternatively, if the method determines that the data state identifier and the parity state identifier differ, the method generates an error message.

Abstract: A method for processing a point-in-time copy of data associated with a logical storage volume where the data to be copied is stored in a striped or parallelized fashion across more than one physical source volume. The method includes receiving a point-in-time copy command concerning a logical volume and distributing the point-in-time copy command in-band to each of the physical source volumes containing a portion of the striped data. The method also includes establishing a point-in-time copy relationship between each physical source volume and one of a corresponding set of multiple physical target volumes. The method further includes copying the data stored on each physical source volume to the corresponding physical target volume. The in-band copy command and the striped data may be distributed over I/O channels between a server and the physical storage and processed sequentially.

Abstract: A method is disclosed to set the speed of a network. The method supplies a network interconnected with a system controller and a plurality of switch domains, where each of those plurality of switch domains comprises one or more information storage devices and a switch domain controller, and sets by each of the plurality of switch domains a signaling rate for that switch domain. The method queries in-band by the system controller each of the plurality of switch domains for that switch domain's signaling rate, and provides in-band by each of the plurality of switch domains the signaling rate for that switch domain. The method provides in-band by the system controller to each of the plurality of switch domains a first speed selection command specifying a first network speed, and resets by each of the plurality of switch domains the signaling rate for that switch domain to the first network speed.

Abstract: A method is disclosed to selectively provide power to a component disposed in an information storage and retrieval system, where the method supplies a controller comprising a control portion in combination with a plurality of components comprising one or more host adapters, one or more device adapter ports, and a Fibre Channel switch. The method monitors the performance of each of those components. The method discontinues the supply of power to first component while continuing to provide power to the remaining plurality of components. The method then resumes providing power to the first component while continuing the supply of power to the remaining plurality of components.

Abstract: An apparatus is disclosed to convert data from a first sector format to a second sector format. The sector format conversion device includes a processor, and microcode which causes the processor to overlay (N) first sectors having a first sector format onto (M) second sectors having a second sector format, where that sector format conversion device does not include an operating system comprising a user mode and a kernel mode.

Abstract: Systems and methods for diagnosing faults in a multiple domain storage system. Exemplary embodiments include a system for diagnosing faults, the system including independent servers coupled to a serial attached SCSI switch module, end devices coupled to the serial attached SCSI module, at least one external cable connected between the serial attached SCSI module and the plurality of end devices, wherein the external cable defined an external fabric between the serial attached SCSI module and the plurality of end devices; and a process residing on the external fabric, the process having instructions to disable a high speed serializer/deserializer residing on each of the plurality of end devices, enable a universal asynchronous receiver/transmitter interface residing on each of the plurality of end devices, send and receive single ended data and in response to a complete data transfer, disabling the universal asynchronous receiver/transmitter interface and enabling the high speed serializer/deserializer.