Abstract: A method and an apparatus include storing history information into a first storage section that accumulates history information concerning a process performed, transmitting a received acquisition request of the history information accumulated into the first storage section, transmitting the accumulated history information to the history information accumulation section having transmitted the acquisition request, transmitting the history information to the another history information accumulation section, transmitting the acquisition request to the first history information accumulation section at a time of startup, and storing the transmitted history information into a second storage section.

Abstract: Various embodiments for autonomic reclamation processing for tapes are provided. Instructions are received to perform reclamation processing on the formatted tape. Formatted tape is loaded into a tape drive for buffering active data during reclamation processing and consolidating all of the active data in capacity optimized manner on the same formatted tape. The formatted tape comprises metadata denoting active and inactive data blocks for files. The meta data of the formatted tape is read into a reclamation memory. The table is sorted and a starting block address is sorted. All active files ordered in the table starting at the starting block address are read into the reclamation memory. The files are written from the reclamation memory to the formatted tape from the starting block address and updating the table with new block addresses of the files. The meta data is updated with the updated table.

Abstract: Provided is a method of controlling a computer system which includes a host computer and one or more storage systems coupled to the host computer via a network, wherein the first processor executes an application job which executes data I/O in a logical storage area; the second processor executes a management job which executes the data I/O in the logical storage area; the method comprising: judging whether at lest one of resources of the computer system used for the data I/O of the application job is also used for the data I/O of the executed management job when performance of the application job drops below a predetermined threshold; and displaying information indicating the executed management job when it is judged that at least one of the resources used for the data I/O of the application job is also used for the data I/O of the executed management job.

Abstract: A magnetic tape drive having a tape drive system for moving magnetic tape, tape read/write and servo system, tape cartridge load/unload systems, I/O communications, memory; and a control system, operates in three modes to conserve energy consumption. A first low power mode powers the I/O communications, the memory, and the control system. If a magnetic tape cartridge is in loaded position in the magnetic tape drive, the second low power mode powers the same as the first low power mode, and additionally powers the tape drive system to apply tension to a magnetic tape of the magnetic tape cartridge. In the first and the second low power modes, the control system operates the I/O communications, the memory and the control system to respond to and execute commands received at the I/O communications if the commands are executable without magnetic tape access. The third, full power mode, is entered if a command received at the I/O communications requires magnetic tape access.

Abstract: Embodiments of the invention relate to a (e.g., hybrid) redundant array of independent disks (RAID)-based storage control board. Specifically, the present invention relates to a storage control board having a RAID controller with a peripheral component interconnect express (PCI-e) interface. In one embodiment, the RAID controller is coupled to an input/output (I/O) hub and a set (at least one) of PCI-e slots, which themselves can receive cards such as a fiber channel (FC) add-on card, a serial attached small component system interface (SAS) add-on card, or a PCI-e bridge add-on card. The I/O hub can be coupled to a set (at least one) of processors, each of which can be coupled to a main memory module or the like.

Abstract: A method, computer management apparatus, and computer program product are provided for processing data stored on a sequential storage media within a computational computing environment. A block reference table and most often read blocks are loaded from a modified tape format of a sequential storage media into an internal memory of a sequential storage media device. During write command processing, a data deduplication procedure is performed using a modified block reference table. It is determined if entries from the block reference table must be deleted and responsive to this identifying and deleting host block and device block entries from the block reference table.

Abstract: Data indicating a plurality of groups into which data to be accessed from one or more storage media has been divided is received. For each of at least a subset of the groups a parallelization limit for that group is received. A first parallelization limit for a first group in the subset is not necessarily same as a second parallelization limit for a second group in the subset.

Abstract: Apparatuses, methods, and systems related to IP-addressable partitions are disclosed. In some embodiments an IP address is used to uniquely identify a selected subset of partitions. Other embodiments may be described and claimed.

Abstract: A storage system, a disk controller, a disk drive and a method of operating thereof. The method includes: configuring a disk drive in a manner enabling executing one or more read requests concurrently with executing one or more write requests addressed to the same data track of the disk drive; responsive to a received write request addressed to a certain track of the disk drive, identifying with the help of the control layer one or more read requests concurrent to received write request and addressed to the same track; if the received write request and the identified one or more read requests match a predefined criterion, generating and issuing, with the help of the control layer, a command to the disk drive for executing a single task corresponding to the concurrent read and write requests combined in accordance with a certain mask.

Abstract: Timing at which a rotation of a physical disk can stop is taken to more appropriately stop the rotation of the physical disk.

Abstract: A device management utility is described that includes a generalized graphical user interface facilitating access to a variety of resources associated with selected device types. In particular, the utility includes information interfaces communicatively linking the utility of a variety of data sources. In addition, the utility includes a graphical user interface display providing a variety of information associated with a selected device type. Such information includes device identification information, links to supplemental resources, and a set of screen selection controls for exposing multiple functional modes of operation of the device management utility.

Abstract: A mobile telephone has a rendering functionality for rendering media stored in storage, and a user interface for user control. A host processor controls the communication functionality and the user interface. The co-processor controls the rendering of the media. The host processor has high power consumption in an active mode and low power consumption in a sleep mode. The co-processor conditionally supplies wake-up signals to the host processor. Upon receipt of a particular wake-up signal, the host processor switches from the sleep mode into the active mode. In the active mode, the host processor transfers a particular media segment to the co-processor before switching back to the sleep mode. The co-processor buffers the segment before rendering it. Upon detecting a low buffer level the co-processor supplies a next wake-up signal to the host processor for initiating transfer of a next media segment.

Abstract: Each communication path between controllers and a plurality of storage devices has a plurality of expanders coupled in series. In order to shorten the time during which the communication path is not used for I/O, either (A) the length of time for which I/O suppression is set for the communication path is shortened, or (B) the overall time it takes for processing other than I/O processing is shortened. In the (A), a determination as to whether or not the coupling between the expanders has been disconnected is made for the I/O-suppressed communication path, and in a case where the result of this determination is negative, a discover process is carried out after releasing the I/O suppression with respect to this communication path. In the (B), the number of command issue times of updating routing control information of the expander is reduced.

Abstract: A storage system has multiple disk controller (DKC) units that are coupled to one another in accordance with a coupling mode that satisfies the following (a1) through (a3): (a1) One DKC inside one DKC unit and one DKC inside another DKC unit are coupled via a second type of coupling medium that differs from the internal bus of the DKC and has a longer maximum communication distance than a first type of coupling medium, which is the same type of coupling medium as the internal bus of the DKC; (a2) the one DKC unit virtualizes a logical volume of the other DKC unit and provides this virtualized logical volume to host(s) coupled to the one DKC unit; and (a3) the other DKC unit virtualizes a logical volume of the DKC unit and provides this virtualized logical volume to host(s) coupled to the other DKC unit.

Abstract: A solid state memory drive includes a first interface for receiving solid state memory cartridges; and a second interface for communicatively coupling the solid state memory drive unit with a host system through a drive bay configured to house a cassette tape drive. A host system then includes at least one drive bay configured to receive either the solid state memory drive or a tape cassette drive. A method includes removing a magnetic tape cassette drive from the drive bay; and inserting a solid state memory cartridge drive into the drive bay so as to communicatively interface the solid state memory cartridge drive and the host system.

Abstract: A library apparatus includes a medium name storage unit that stores medium name conversion information in which a virtual medium name specifying a storage medium in a read/write request from a host is related to a real medium name specifying the storage medium in the library apparatus, a conveying mechanism unit that conveys the storage medium, a drive that reads/writes data from/to the storage medium conveyed by the conveying mechanism unit in response to the received read/write request, a conversion unit that converts the virtual medium name included in the received read/write request to the real medium name on the basis of the medium name conversion information stored in the medium name storage unit, and a conveying mechanism control unit that controls the conveying mechanism unit to convey the storage medium having the real medium name converted by the conversion unit to the drive.

Abstract: In order to avoid loss of data, computer systems are often connected to a UPS which provides power backup in case of an emergency shutdown resulting from a power failure. However, as UPS units are costly, they take up a lot of physical space and can provide power for a limited period of time, it would be advantageous to improve the efficiency of UPS devices and enable to utilize as much as possible of the UPS power in order to save data to a permanent storage before shutdown. There is provided a method and system for controlling the frequency of one or more processors in computer systems, responsive to an indication of a power failure, and thereby reduce its power consumption, so as to provide more power for writing write-pending data to a non-volatile data storage.

Abstract: A system and method for reading files stored on a storage system is disclosed. The method includes communicatively coupling one or more remote systems for reading files stored in storage with a first set of files according to a predetermined data format and in a cache memory with a second set of files, the second set of files being a subset of the first set of files. Next one or more remote systems are received at least one read request for reading a sequence of files. A determination is made, among the files of the sequence of files, whether one or more cached files are already stored in the cache memory and whether one or more remaining files are not already stored in the cache memory. Creating, within the one or more remaining files, an order according to which the remaining files should be read on the storage system.

Abstract: Changes are tracked by tracking a change request which when performed by a disk driver changes a portion of disk storage. The change request is allowed to pass to the disk driver to be performed by the disk driver. Information associated with the change request is stored in an operating system's persistent storage. A differential backup is performed using the information associated with the change request stored in the operating system's persistent storage after a system, which includes the disk driver and the disk storage, has shut down and restarted.

Abstract: A wireless communication device is provided. The device is connectable to a first wireless network including an access point and a second wireless network including a terminal having an access point function. The device includes a setting section which stores setup data in a volatile storage area, a communication section which performs wireless communication using the setup data stored in the volatile storage area, and a determination section which determines which wireless networks the device is to be connected to. If the device is to be connected to the first wireless network, the setting section stores first setup data from the access point into the volatile storage area and a non-volatile storage area. If the device is to be connected to the second wireless network, the setting section stores second setup data from the terminal into the volatile storage area without storing it into the non-volatile storage area.

Abstract: A method begins by a processing module determining a retrieval threshold for retrieving a set of encoded data slices from a dispersed storage network (DSN), wherein the set of encoded data slices represents data encoded using a dispersed storage error encoding function having a pillar width of “n”, a decode threshold of “k”, and an encoding ratio of n?k>k and wherein the retrieval threshold is in accordance with the encoding ratio. The method continues with the processing module issuing data retrieval requests to the DSN for the set of encoded data slices and receiving encoded data slices of the set of encoded data slices to produce received encoded data slices. The method continues with the processing module decoding the received encoded data slices to recapture the data when a number of received encoded data slices compares favorably to the retrieval threshold.

Abstract: Methods, systems, and non-transitory computer readable media for advanced power management for serial advanced technology attachment (SATA)-based storage devices are disclosed. According to one aspect, the subject matter described herein includes a method for advanced power management of SATA-based storage devices. The method includes, at a SATA-based storage device having a controller, a non-volatile memory for storing data, and a communication interface for communicating with a host, receiving from the host a command to enter a quiescent mode. In response to receiving the command to enter a quiescent mode, the storage device enters a quiescent mode. The storage device receives from the host an indication that the storage device should enter a low power mode. In response to this indication, the storage device puts at least a portion of the non-volatile memory into a low power mode while maintaining at least a portion of the controller in normal power mode.

Abstract: A method of recording, and an apparatus for recording, data on a write-once disc, and the write-once disc used with the method and the apparatus. The write-once disc includes a plurality of update areas in which to record a predetermined type of updated information, at least one main access information area (AIA) in which to record main access information (AI), the main AI indicating a final update area in which finally updated information is recorded, among the plurality of update areas, and at least one sub AIA in which to record sub AI, the sub AI indicating a location of the finally updated information recorded in the final update area.

Abstract: Embodiments of the present invention relate to a (e.g., hybrid) redundant array of independent disks (RAID)-based storage control board having a fiber channel interface controller. Specifically, the present invention relates to a storage control board having a RAID controller with a peripheral component interconnect express (PCI-e) interface and a fiber channel interface controller. In one embodiment, the RAID controller is coupled to an input/output (I/O) hub and a set (at least one) of PCI-e slots, which themselves can receive cards such as a fiber channel (FC) add-on card, a serial attached small component system interface (SAS) add-on card, or a PCI-e bridge add-on card. The I/O hub can be coupled to a set of processors, each of which can be coupled to a main memory module or the like.

Abstract: A technique applicable during the transfer of data to and from a memory involves: operating a memory interface using memory access cycles that each transfer a quantity of data D across the memory interface; receiving a request to transfer a quantity of data Q across the memory interface; and calculating a value M as a function of a plurality of parameters, M being a minimum number of the memory access cycles needed to carry out the transfer of the quantity of data Q across the memory interface, wherein the calculating includes determining a logarithm of one of the parameters, and then determining the value M as a function of the logarithm.

Abstract: A virtual storage system includes a storage subsystem having virtual storage devices to emulate physical storage devices of an actual storage system. The virtual storage system has a controller to detect a status change of a particular physical storage device in the actual storage system. The status change includes at least one of loading of the particular physical storage device and ejecting of the particular physical storage device. In response to detecting the status change of the particular physical storage device, the controller performs synchronization between the virtual storage system and the actual storage system by updating a state of a corresponding virtual storage device in the virtual storage system.

Abstract: A digital Storage Element is described. A device is configured including a Storage Element for access by a user responsive to a native control code. A processing arrangement executes a control program for controlling the overall device and executing at least a portion of the native control code as part of the control program for interfacing with the Storage Element. A programming arrangement is provided separate from the device for customizing a read channel within the Storage Element. Command, user interaction and data transfer execution are discussed for mitigation of potential mechanical shock effects. Status indications relating to the Storage Element are provided including head position and mechanical shock. Calibration, test and operational monitoring procedures, for using head position status, are described. Failure configuration monitoring is provided in tracking overall performance and design considerations.

Abstract: A system and method for managing automatic data protection features, e.g., backup scheduling and data storage capabilities, e.g., policy provisioning of a storage system to enable information lifecycle management of data served by the system. A novel management module executes within a storage operating system of the storage system to manage the automatic scheduling of backup operations for data based on a minimal set of user configurations. The management module cooperates with a mirroring application to manage the generation of persistent consistency point image (PCPIs) used as backups (replicas) of the data. The management module distributes the data containers scheduled for PCPI generation among time slots within a defined backup time window. At the appropriate time slot, each PCPI the data container is illustratively backed up from the primary storage space to the secondary storage space.

Abstract: Managing power-consumption, for use in a storage system comprising first data stored on one or more storage devices is provided. A receiver receives a policy comprising a power-management parameter, a first parameter and a rule associated with the policy. An analyser, responsive to receipt of a policy, analyzes second data associated with the rule. A determiner, responsive to the analysis, determines third data in accordance with the second data. The third data is associated with migration of the first data.

Abstract: Described are techniques for performing a data storage management task. A presentation technology service layer renders a user interface for user interaction in accordance with one or more rendering techniques. A user interaction template service layer includes one or more templates. Each of the templates describes processing to perform the data storage management task. A user interface data model mapping service layer communicates with at least one of a business logic service layer and a data storage interface layer to perform one or more operations in connection with the data storage management task and to map data received therefrom in a form for use by the user interface in accordance with a user interface data model.

Abstract: A protocol chip and a communication conversion circuit are provided in a channel adapter package that is in charge of communications with a host. The communication conversion circuit communicates with the protocol chip using a procedure that conforms to a communication protocol. The communication conversion circuit communicates with a microprocessor using a procedure that is common to multiple communication protocols. It appears from the microprocessor as though communications are being carried out with the same type of channel adapter package.

Abstract: A method for monitoring and predicting health of tape drives and media in a tape library. The method includes receiving exchange data associated with an exchange in the tape library. Then the method includes, with an analytics module, processing the exchange data to determine gain types for the exchange. Based on the gain type, a health gain value is assigned to a tape drive and media and current suspicion level values are independently assigned to the tape drive and the media. The method includes assigning a first health indicator to the media and a second health indicator to the tape drive based on these two suspicion level values. In some embodiments of the method, the current suspicion level value calculating step includes summing the health gain value with a number of health gain values assigned to the tape drive and the media for up to a predefined number of monitored exchanges.

Abstract: In a file server, a file system is built upon a volume of data storage. The file system includes multiple cylinder groups. Each cylinder group includes file system blocks. The file system blocks include allocated blocks and free blocks. The volume includes slices of storage, and each slice stores at least one of the cylinder groups. A hierarchical slice map has a top level that includes a count of free blocks in the file system, an upper level that includes a count of free blocks in groups of the slices, an intermediate level that includes a count of the free blocks in sub-groups of the slices, and a bottom level that includes a count of the free blocks in each slice of storage. To find a free block for allocation to a file, the slice map hierarchy is searched in a top-down fashion.

Abstract: A management computer includes a communication device for communicating with a storage system and a plurality of computers. The management computer also includes a processor executing to: store relation information between the storage system and the plurality of computers; collect a plurality of computer performance information about computer-side I/O loads generated by programs on the plurality of computers, from the plurality of computers; identify a storage resource from a plurality of storage resources in the storage system; and identify at least one computer performance information from the plurality of computer performance information based on the relation information; and output the at least one computer performance information to a display. The at least one computer performance information corresponds to a certain computer-side I/O load that generates a load to the identified storage resource.

Abstract: An electronic device receives satellite signals from positioning information satellites and acquires positioning information and time information. A stored data table comprises a first block of data having a first array of time difference data and a second block of data having a second array of time difference data that is different than the first array of time difference data. A stored memory address table stores the memory address of each of the first and second blocks of data, at least one the blocks of data being stored a plurality of times in the memory address table. The data block corresponding to the acquired positioning information is identified, the memory address corresponding to that data block is read, the data block data indicated by the memory address is acquired, and the time difference data for the segment corresponding to the positioning information is acquired from the data block.

Abstract: Dynamic provisioning of available space in a data storage system without having to configure partitions at system startup is presented. A system table may be maintained with entries corresponding to provisions within the available physical capacity of a data storage system. A volume table may be maintained that includes entries corresponding to territories within a logical data storage volume. When a data write operation is requested, a determination may be made as to whether physical space has been allocated for the territory in the volume that is to be written. If physical space has not yet been allocated, the necessary physical space may be allocated for the territory within the logical volume that is to receive the written data and the requested write operation may be performed. Metadata can be written to disk as to simplify recover from system crashes and unclean shutdowns.

Abstract: An apparatus and a method for operating on data at a cache node of a data grid system is described. An asynchronous future-based interface of a computer system receives a request to operate on a cache node of a cluster. An acknowledgment is sent back upon receipt of the request prior to operating on the cache node. The cache node is then operated on based on the request. The operation is replicated to other cache nodes in the cluster. An acknowledgment that the operation has been completed in the cluster is sent back.

Abstract: The invention discloses a memory management system and a memory management method are disclosed. The memory management system includes a first memory, at least one secondary memory, and a memory management device. The first memory includes a normal access memory bank and at least one switching access memory bank. The secondary memory includes at least one secondary access memory bank corresponding to the switching access memory bank. The memory management device reads/writes the normal access memory bank or the secondary access memory bank.

Abstract: A mechanism is provided for tape writing of small transactions. A first file is written as a plurality of fixed-length data sets (DS), the DS number of the final DS in the plurality of DS is stored in memory as #N(DS#N) and the WP number as #M(WP#M), and the final first file and the second file in the DS following the final DS(DS#N, WP#M) containing the first file are packed and written in sequential DS units, and are stored as DS#N, DS#N+1, etc, and WP#M+1 in sequential order in DS containing the second file. The remaining first, second, or third file is packed and DS#N with WP#M is overwritten as DS#N with WP#M+2, and the remaining #N in the DS numbers of the second file and the third file in the subsequent DS are written as DS#N+1, N+2, etc. with WP#M+2, and the DS#N, #N+1, #N+2, etc. with WP+M+2 are stored.

Abstract: A SAN manager acquires configuration information from devices constituting a SAN and produces a corresponding relationship between a host computer and a virtual volume (virtual volume mapping) and a corresponding relationship between the host computer and a real volume (real volume mapping). Based on those pieces of mapping information, the SAN manager outputs a corresponding relationship between virtual and real volumes. Meanwhile, the failure notification messages received from the in-SAN devices are construed to detect and output an influence of the failure upon the access to a real or virtual volume. Furthermore, when receiving a plurality of failure notifications from the devices connected to the SAN, the plurality of failure notifications are outputted with an association based on the corresponding relationship between real and virtual volumes.

Abstract: A technique for efficiently handling write operation failures in a memory device which communicates with an external host device allows a page of data to be re-written to a memory array from a page buffer. The host provides user data, a first write address and a write command to the memory device. If the write attempt fails, the host provides a re-write command with a new address, without re-sending the user data to the memory device. Additional data can be received at a data cache of the memory device while a re-write from the page buffer is in progress. The re-written data may be obtained in a copy operation in which the data is read out to the host, modified and written back to the memory device. Additional data can be input to the memory device during the copy operation. Page buffer data can also be modified in place.

Abstract: An access control system (10) is disclosed for controlling access to data stored on at least one data storage medium (14) of a computing system. The access control system (10) comprises authentication means (25) to authenticate users permitted to access data stored in the at least one data storage medium (14) and database means (29) arranged to store data access profiles. Each data access profile is associated with a user permitted to access data stored in the at least one data storage medium (14), each data access profile includes information indicative of the degree of access permitted by a user to data stored in the at least one data storage medium (14), and each data access profile includes a master data access profile (M) and a current data access profile (C). The current data access profile (C) is modifiable within parameters defined by the master data access profile (M).

Abstract: One embodiment of the present invention sets forth a hybrid memory module that combines memory devices of different types while presenting a single technology interface. The hybrid memory module includes a number of super-stacks and a first interface configured to transmit data between the super-stacks and a memory controller. Each super-stack includes a number of sub-stacks, a super-controller configured to control the sub-stacks, and a second interface configured to transmit data between the sub-stacks and the first interface. Combining memory devices of different types allows utilizing the favorable properties of each type of the memory devices, while hiding their unfavorable properties from the memory controller.

Abstract: A network memory system for ensuring compliance is disclosed. The network memory system comprises a first appliance configured to encrypt first data, store the encrypted first data in a first memory device. The first appliance also determines whether the encrypted first data exists in a second appliance and transmits a store instruction comprising the encrypted first data based on the determination that the encrypted first data does not exist in the second appliance. The second appliance is further configured to receive a retrieve instruction comprising an index at which the encrypted first data is stored, process the retrieve instruction to obtain encrypted response data, and decrypt the encrypted response data.

Abstract: A virtual tape system includes an actual tape device having a magnetic tape which stores data. The virtual tape system includes a virtual tape storage device which stores data stored in the actual tape device as a virtual tape volume, first computers to be connected to a host computer which instructs a storing of data in the actual tape device, and a reading of data from the actual tape device, control an interface with the host computer, second computers which control the virtual tape volume of the virtual tape storage device, third computers which control a writing of the data into the actual tape device, and a local disk controller which stores the data in one of storage devices mounted one in each of the first computers, each of the second computers, and each of the third computers.

Abstract: When using virtually stored data sets, such as virtual storage access method (VSAM) data sets, while the data set is open (referred to as an open time) static data set characteristics and/or job parameters have been defined for the VSAM data set. In one approach, even after a data set is opened, a virtually stored control block structure for the data set may be modified, such as by providing a dynamic address space associated with the data set in order to interact with the data set in an environment which allows for a service block request to modify the control block structure, such that data set characteristics and/or job parameters for the data set may be modified during the open time of the data set.

Abstract: An improved non-volatile memory and logical block to physical block address translation method utilizing a cluster based addressing scheme is detailed. The translation of logical blocks/sectors to the physical blocks/sectors is necessary for a non-volatile memory to appear as a freely rewriteable device to a system or processor. Embodiments of the present invention utilize cluster based address translation to translate logical block addresses to physical block addresses, wherein each cluster contains a plurality of sequentially addressed logical blocks. This allows the use of a smaller RAM table for the address translation lookup and/or faster scanning of the memory device or memory subsystem for the matching cluster address. In one embodiment, a specially formatted cluster is utilized for frequently updated sectors/logical blocks, where the cluster stores a single logical block and a new sequential physical block of the cluster is written in turn with each update.

Abstract: A network memory system comprises a first appliance and a second appliance. The first appliance receives data and determines whether a portion of the data is locally accessible to the second appliance. The first appliance generates an instruction based on the determination and transfers the instruction to the second appliance over a communication network. The second appliance receives the instruction from the first appliance over the communication network and processes the instruction to obtain the data. The second appliance then transfers the data to a computer.

Abstract: A device controller that improves transfer speed when the total data amount to be transferred exceeds a predetermined amount, without requiring a special configuration in the device. The device controller includes a cache memory that caches data received from an application software or device driver and data received from a target device, and a control unit that transfers the data cached in the cache memory to the target device and the application software or device driver. The control unit receives a read or write request from upstream and caches the transfer data in the cache memory. During writing, the data received from upstream is cached, and once a certain amount of data has been collected, it is sent downstream. During reading, a certain amount of data is collectively read out from downstream and sent upstream.

Abstract: A system and method for providing a command queue selection scheme by selecting commands by giving preference to commands based on the power consumption characteristics the command. In one embodiment the selection scheme involves calculating the value of the cost of energy saving associated with the access of a command by an evaluation function Costi=EAT+C×F1 (seek distance, latency). C is a dynamically adjustable power control function that determines how much power decreases with the selection of a particular command and F1 is a functional calculation of the power consumption value associated with the particular command. In one embodiment commands with low power consumption will be accessed in preference to commands with shorter seek distance.