Abstract: According to one embodiment, a memory system has a data transfer device which includes a first command generating unit, a second command generating unit, a first storage unit, a second storage unit, and a nonvolatile memory managing unit. The first command generator generates a first command for reading out data from a nonvolatile memory to a host apparatus. The second command generator generates a second command for internal processing of the memory system associated with a temporary memory and the nonvolatile memory. The first memory has a queue structure configured to store the first command. The second memory has a queue structure configured to store the second command. The memory manager is configured to read out the first command stored in the first memory in priority to the second command stored in the second memory and to transmit read-out command to the nonvolatile memory.

Abstract: Described herein are methods, systems, apparatuses and products for cost-aware replication of intermediate data in dataflows. An aspect provides receiving at least one measurement indicative of a reliability cost associated with executing a dataflow; computing a degree of replication of at least one intermediate data set in the dataflow based on the reliability cost; and communicating at least one replication factor to at least one component of a system responsible for replication of the at least one intermediate data set in the dataflow; wherein the at least one intermediate data set is replicated according to the replication factor. Other embodiments are disclosed.

Abstract: Described herein is a system and method for migrating data from a source storage site to a destination storage site. The data may be comprised within storage objects (e.g., flexible volumes). A base storage object may comprise a parent storage object and a storage object clone may comprise a storage object that is derived from the base storage object. As such, a hierarchical relationship exists between the base storage object and the storage object clone. The storage object clone may comprise a writable point-in-time image of the parent storage object. If a migration of the base storage object and the storage object clone is performed, then the hierarchical relationship between the base storage object and the storage object clone is retained after the storage objects are migrated from the source storage site to the destination storage site. As such, the system and method for migrating data may enable storage space and network bandwidth savings.

Abstract: A method, computer program product, and system for dynamically distributing data for parallel processing in a computing system, comprising allocating a data buffer to each of a plurality of data partitions, where each data buffer stores data to be processed by its corresponding data partition, distributing data in multiple rounds to the data buffers for processing by the data partitions, where in each round the data is distributed based on a determined data processing capacity for each data partition, and where a greater amount of data is distributed to the data partitions with higher determined processing capacities, and periodically monitoring usage of each data buffer and re-determining the determined data processing capacity of each data partition based on its corresponding data buffer usage.

Abstract: A method, computer program product, and system for dynamically distributing data for parallel processing in a computing system, comprising allocating a data buffer to each of a plurality of data partitions, where each data buffer stores data to be processed by its corresponding data partition, distributing data in multiple rounds to the data buffers for processing by the data partitions, where in each round the data is distributed based on a determined data processing capacity for each data partition, and where a greater amount of data is distributed to the data partitions with higher determined processing capacities, and periodically monitoring usage of each data buffer and re-determining the determined data processing capacity of each data partition based on its corresponding data buffer usage.

Abstract: A computer system which includes a plurality of threads and a garbage collector that traces memory objects and identifies memory objects according to a three-color abstraction. The computer system also includes two methods of deleting compiled code in a self-modifying multi-threaded computer system. The computer system also utilizes a method of handling links between fragments of code in a self-modifying multi-threaded computer system. The computer system also handles patches between two pieces of code.

Abstract: Storage systems and methods are presented. In one embodiment, a storage reclamation method comprises performing a potential reclamation identification process, wherein the potential reclamation identification process includes determining if there is the potential for reclaiming storage resources; performing a reclamation process, wherein reclamation is performed on storage resources identified by the potential reclamation identification process as being eligible for reclamation, and wherein the storage resources correspond to free space associated with a data file; and performing a valid free space indication process, wherein a valid free space indication process includes forwarding a valid free space indication recognizable to an application as a valid free space indication when the application attempts to direct a read to the storage spaces reclaimed by the reclamation process.

Abstract: A computer system and a sleep control method thereof are provided. The method includes following steps: when a computer system enters a sleep mode, storing a system parameter into a dynamic random access memory (DRAM) via a central processing unit (CPU); storing the system parameter in the DRAM to a flash memory via a bridge unit; and entering the sleep mode or a power off mode. According to the disclosure, to wake up the computer system is more rapidly and power saving.

Abstract: The invention relates to apparatus and methods for managing data swap in a migration of virtual memory data of a virtual machine. In one embodiment, an apparatus comprises a receiving unit configured to receive a migration instruction and the second site information; a copying unit configured to copy memory data to a sub-logical unit in the first storage device; and a notifying unit configured to send a notification to instruct the second host to read the memory data from a mirror logical unit of a sub-logical unit in the second storage device. The apparatus modifies a mirror direction between the first and second storage devices and modifies a path table related to the first and second storage devices. Data of the virtual machine can be migrated and swapped in a metro mirror manner, thereby the virtual machine data can be migrated across sites without affecting system operation.

Abstract: According to one embodiment, a memory system includes a first memory chip includes a first temporary memory and a first block, a second memory chip includes a second temporary memory and a second block, and a memory controller that controls writing of logical pages to the first and second memory chips. The memory controller forms a second unit having the same page number as the first unit by the first temporary memory and the lowermost physical page in the first block, forms a third unit having the same page number as the first unit by the second temporary memory and the lowermost physical page in the second block, and writes the logical pages by an interleave operation in order of the second unit, the third unit, the first unit in the first block, and the first unit in the second block.

Abstract: Techniques for launching a VM with memory automatically adjusted based on a memory configuration of a client hosting the VM are described herein. According to one embodiment, a control server dynamically determines an amount of memory in view of a memory configuration of a client at the point in time, in response to a request for launching a VM for the client over a network. The amount of memory is allocated to be associated with the VM. Thereafter, the control server launches the VM for the client having the determined amount of memory allocated to the VM, where the VM is to be hosted by the client. Other methods and apparatuses are also described.

Abstract: A chassis management controller includes a root file system, a shared memory, a daemon process module, and an interposer library. The root file system includes a plurality of directories associated with firmware applications of the chassis management controller. The daemon process module is configured to read the parameters of the directories, and to create, in the shared memory, a table including parameters of the directories. The interposer library is configured to intercept an input/output library call for an operation associated with one of the firmware applications, to read table entries associated the one or the firmware applications, to determine whether the operation associated with the input/output library call would result in an over-allocation of a parameter in the entries of the table, and if the operation would not result in the over-allocation, pass the output operation to a standard system library, otherwise to return an out of space error message.

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: A method and device for storing and reading/writing composite document are disclosed. The method includes: an initial storing area is pre-allocated for an inner controlling stream of the composite document and the initial storing area is continuous sectors or sector clusters; the inner controlling stream is stored in the initial storing area. The patches of a user data stream and the inner controlling stream in the composite document are reduced using the method or device. Correspondingly, pre-allocating storing area makes the probability of continuously storing the user data stream and the inner controlling stream in the composite document increased. The I/O can be optimized by introducing a strategy of reading cache and writing in a batch size, which can improve the efficiency of reading and writing.

Abstract: The relay unit splits the storage area in the buffer into a plurality of partitioned areas, manages the same and, upon receiving a read request from the access request source, selects and allocates one or more from the plurality of partitioned areas and, on condition that the relevant partitioned areas are allocated, transmits the read request to the memory control unit, wherein the memory control unit reads the data requested in the received read request from the memory, splits the data which is read into a plurality of units, and transmits the same to the relay unit, wherein the relay unit stores each of the data transmitted from the memory control unit in each of the allocated partitioned areas sequentially, on condition that all of the data is stored, reads each of the data from each of the allocated partitioned areas, compiles each of the data which is read into one, transmits the same as read data to the access request source, and releases all of the respective allocated partitioned areas.

Abstract: Memory devices, systems and methods are described, such as those including a dynamically configurable channel depth. Devices, systems and methods are described that adjust channel depth based on hardware and/or software requirements. One such device provides for virtual memory operations where a channel depth is adjusted for the same physical memory region responsive to requirements of different memory processes.

Abstract: A memory access monitoring method and a memory access monitoring method device are disclosed, The method comprises: performing coarse grain monitoring on local memory pages, if a hot page with coarse grain monitoring exists in the local memory pages, requesting an operating system to perform an optimized migration for the content of the hot page, and if a half hot page with coarse grain monitoring exists in the local memory pages, initiating fine grain monitoring to the half hot page; and performing fine grain monitoring on the half hot page, if a hot area with fine grain monitoring exists in the half hot page, requesting the operating system to perform an optimized migration for the content of the hot area.

Abstract: A method may include distributing ranges of addresses in a memory among a first set of functions in a first pipeline. The first set of the functions in the first pipeline may operate on data using the ranges of addresses. Different ranges of addresses in the memory may be redistributed among a second set of functions in a second pipeline without waiting for the first set of functions to be flushed of data.

Abstract: An apparatus of the present invention includes partition selection circuitry configured to selectably provide individual access to multiple ones of a plurality of partitions of a data storage component by a host device without multiple partition support. The apparatus can also include the data storage component and/or the host device. The partition selection circuitry uses a logical block addressing (LBA) address generated by the host device, and an operating mode indicator indicative of a particular partition, to allow the partitions of the data storage component to be accessed by the host device without multiple partition support. Methods implemented by the apparatus are also disclosed.

Abstract: An apparatus includes a first processor that accesses memory according to a first clock frequency, a second processor that accesses memory according to a second clock frequency, and a memory device is configurable to selectively operate according to the first clock frequency or the second clock frequency. A memory controller enables dynamic configuration of organization of the memory device to allow a first portion of the memory device to be accessed by the first processor according to the first clock frequency and a second portion of the memory device to be accessed by the second processor according to the second clock frequency.

Abstract: Systems and methods for managing storage virtualization in a storage infrastructure are provided. The method comprises examining storage virtualization configurations across a data storage infrastructure having one or more data storage resources, such that configuration data associated with the storage virtualization configurations applied to the one or more data storage resources is stored in a configuration repository; analyzing the configuration data to detect storage virtualization policy inconsistencies across the data storage infrastructure; reporting potential problems associated with applying the storage virtualization configurations to said one or more data storage resources; and automatically implementing recommendations for corrective action to improve storage virtualization, in response to detecting the virtualization policy inconsistencies.

Abstract: A CPU measures time. A memory unit stores the values of the times measured by the CPU as data groups for each measuring of time, and stores the data groups in association with protection information showing whether the data groups are in a protection state or an unprotected state. An input switch receives an instruction as an input. The CPU sets protection information stored in the memory unit on the basis of the instruction received by the input switch. Further, the CPU deletes the data of data groups in an unprotected state from the memory unit, on the basis of the protection information stored in the memory unit, when there is no capacity for storing the measured time values in the memory unit.

Abstract: Managing commands in a buffer is simplified while continuing to enable immediately executing real-time commands. A control unit of a printer sequentially writes commands received from a host computer to a first buffer and sequentially reads the commands. If the read command is a real-time command, the control unit executes the command. If the read command is a normal command, the control unit writes the command to a second buffer without executing the command from the first buffer. The control unit sequentially reads and executes normal commands written to the second buffer.

Abstract: A method for implementing a disk array, and a method and apparatus for reading or writing data are provided in embodiments of the present invention. The method includes: creating logical partition regions, where each logical partition region corresponds to one controller in one controller group; recording a mapping relationship between the logical partition regions and the controllers in a controller mapping table; and allocating, chunklets for the logical partition regions from a physical disk that is managed by a controller in a controller group that is corresponding to each logical partition region, and recording a mapping relationship between the logical partition regions and the chunklets in a chunklet mapping table. In the present invention, a chunklet in a physical disk that is managed by a controller in the same controller group is set to corresponding to each logical partition region, so that an expansion operation is completed easily.

Abstract: A system and method deallocates data blocks in virtual environments with high efficiency. A computer system hosting a virtual machine includes an I/O device driver in the guest operating system of the virtual machine. The I/O device driver intercepts an operation performed by the guest operating system that causes a data block to be deallocated in the virtual machine. The I/O device driver informs a hypervisor of the computer system that the data block is to be deallocated. The hypervisor then instructs the data storage to deallocate the data block for reuse.

Abstract: A storage system 1000 providing a storage area to an external device 1500 comprises a plurality of storage apparatuses 1100, 1200 and 1300 of different performance capabilities, and a storage controller 2600. The storage controller 2600 holds storage cost coefficients 3202 of the respective storage apparatuses 1100, 1200 and 1300, user cost allocation information 3302 for each user using the storage system 1000 from the external device 1500, and user cost distribution information 3402 that defines, for each user, proportions of an available space amount distributed to the storage apparatuses 1100, 1200 and 1300. The storage controller 2600 calculates an ideal utilization 3502 for each user, from the storage cost coefficients 3202 and the user cost distribution information 3402, and allocates, for each user, the ideal utilization 3502 to each of the storage apparatuses 1100, 1200 and 1300, in the order of the performance capabilities from highest to lowest.

Abstract: A method for writing data to a disk drive. The method includes: receiving a write command; and, determining whether a beginning and an end of a rewrite area specified by the write command agree with boundaries of large-sized data sectors on a disk. The method also includes: reading head and tail data sectors and making a backup of the head and tail data sectors in first and second non-volatile memory areas, respectively, if the beginning of the rewrite area does not agree with the boundaries. The method includes starting a rewrite of the rewrite area after completing backups into first and second non-volatile memory areas. Moreover, the method includes: determining a state stage by using data in first, second, third and fourth non-volatile memory areas if a power shut-down occurs during execution of the write command; and, executing a recovery process in accordance with the determined state stage.

Abstract: A data access method for accessing a non-volatile memory module is provided. The data access method includes configuring a plurality of logical addresses and grouping the logical addresses into logical blocks to map to the physical blocks of the non-volatile memory module, and a host system formats the logical addresses into one partition by using a file system and the partition stores at least one file and a file description block corresponding to the file. The data access method further includes searching an end mark corresponding to entry values of the file description block, setting logical addresses storing the end mark as default pattern addresses, and setting values stored in the logical addresses as default values corresponding to the default pattern addresses. Accordingly, the data access method can divide one partition into a write protect area and a writable area by updating data stored in the default pattern addresses.

Abstract: Mechanisms for memory management in a scoped memory system are provided. The scoped memory system includes a scoped memory area for the allocation of objects therein for access by one or more software threads in execution. The scoped memory area has an associated thread count for indicating that the scoped memory area is discardable. The mechanisms identify a set of root references for objects allocated in the scoped memory area and recursively traverses and marks objects that are referenced from the set of root references and that are allocated in the scoped memory area. The mechanisms further identify objects in the scoped memory area that are not so marked and discards the identified objects.

Abstract: A processor includes: a first storage that stores data stored in a main storage; a processor that outputs an instruction for loading data from the main storage into the first storage; a second storage that holds a instruction until the first storage receives the data requested by the instruction; a first controller that reads the data requested by an instruction from the first storage and transfers the requested data to the processor, when the requested data is in the first storage, or but, transfers the received instruction to the main storage, when the requested data is not in the first storage and an instruction requesting the same data as the requested data is not in the second storage; and a second controller that completes reading the data requested by an instruction, when an instruction requesting the same data as the requested data is in the second storage.

Abstract: A data storage system includes a host interface configured to be coupled to a host device, to receive data from the host device, and to send data to the host device and a memory. The data storage system further includes a primary compression engine coupled to the host interface and to the memory, wherein the primary compression engine is configured to compress data received from the host device via the host interface and to store the compressed data in the memory, and wherein the primary compression engine is further configured to decompress compressed data stored in the memory prior to the decompressed data being sent to the host device via the host interface.

Abstract: System and method for reducing costs of moving data between two or more of multi-tiered storage devices. Specifically, the system operates by moving only high tier portion of data and merely remapping the low tier data to migration target device, which eliminates a large amount of data movement (low tier) while maintaining the SLA of high tier data. Specifically, when a command to migrate a thin provisioned volume is received from a source primary storage device to another target primary storage device, the system doesn't copy all of the tier1 and tier2 chunk data that the source thin provisioned volume holds, but copies only tier1 chunk data to the target storage device. The copy operation is performed after the storage system prepared the target thin provisioned volume on the target side. After that, tier2 chunks are remapped from the primary storage device to another target primary storage device without copying.

Abstract: A memory manager secures memory areas according to requests from programs and sets ranks designated by the programs to the secured memory areas. The memory manager selects a memory area released on the basis of the rank of each memory area, from the secured memory areas, when an available capacity of a main storage device is insufficient. The memory manager releases the selected memory area and secures a new memory area. The present disclosure can be applied to an embedded apparatus.

Abstract: In an embodiment, a processor may be configured to detect a store exclusive operation followed by a memory barrier operation in a speculative instruction stream being executed by the processor. The processor may fuse the store exclusive operation and the memory barrier operation, creating a fused operation. The fused operation may be transmitted and globally ordered, and the processor may complete both the store exclusive operation and the memory barrier operation in response to the fused operation. As the fused operation progresses through the processor and one or more other components (e.g. caches in the cache hierarchy) to the ordering point in the system, the fused operation may push previous memory operations to effect the memory barrier operation. In some embodiments, the latency for completing the store exclusive operation and the subsequent data memory barrier operation may be reduced if the store exclusive operation is successful at the ordering point.

Abstract: The management computer allocates a volume of an external storage device to a host so as to satisfy performance requirements specified from the host. The management computer selects a path that is formed including a first port of the storage device and a second port of the external storage device and that satisfies the performance requirements from the host, and then sets the priority. The management computer sets to the host the use authorization of a primary port and a secondary port that constitute a selected path and the use authorization of a second logical volume.

Abstract: A system and method for logging for asynchronously replicating volume groups. A write request to write data to a location in a volume may be received. Metadata associated with the write request may be stored. It may be determined if the write request possibly overlaps with one or more earlier write requests to the volume that have not yet been replicated to a secondary storage. The data may be stored in a replication log only if the write request possibly overlaps with one or more earlier write requests to the volume. The data may not be stored in the replication log if the write request does not overlap with one or more earlier write requests to the volume. The data may be written to the location in the volume. Changes to the volume may periodically be replicated to the secondary storage using the replication log.

Abstract: In response to a query of a decision tree, a first packed node of the decision tree is copied from a system memory into a direct memory access (“DMA”) memory. In response to copying the first packed node from the system memory into the DMA memory, copying is initiated of a second packed node of the decision tree from the system memory into the DMA memory, up to a limit of then-currently available space within the DMA memory. Concurrently with copying the second packed node from the system memory into the DMA memory, the first packed node is evaluated in the DMA memory. In response to evaluating the first packed node, the second packed node is evaluated in the DMA memory without waiting for additional copying of the second packed node from the system memory into the DMA memory.

Abstract: A storage system comprises a plurality of hard disk drives and a storage controller providing a plurality of virtual volumes to a server and including a processor and a memory. The storage controller allocates pages of the plurality of virtual volumes to the plurality of hard disk drives in response to write requests. The storage controller controls to allocate outer sections of the plurality of hard disks to first addresses of the virtual volume and allocates inner sections of the plurality of hard disk drives to second addresses of the virtual volume, wherein the first addresses are lower than the second addresses.

Abstract: An access control apparatus includes an accessor. An accessor accesses a recording medium in which a plurality of partitions are formed. A elector selects any one of a first mode and a second mode. A designator designates at least a part of the plurality of partitions in a manner different depending on a mode selected by the selector. A controller controls a processing operation of the accessor with reference to identification information of the partition designated by the designator, when the mode selected by the selector is the first mode. A sender sends the identification information of the partition designated by the designator in order for an external device to refer, when the mode selected by the selector is the second mode.

Abstract: Provided are method and device for managing a memory in a data stream management system (DSMS) of a portable device. The method includes moving data of a selected memory region that has a low priority to a secondary storage and storing a received data stream in the selected memory region.

Abstract: A storage apparatus configured to store data received from a host system in a drive unit includes a memory unit partitioned into a cache area configured to temporarily store data read out from the drive unit and data to be written in the drive unit and an information storage area assigned for a memory pool configured to hold information for internal processing of the storage apparatus; an information-storage-area management table in which information-storage-area management information including position information on the memory pool in the memory unit is registered; a cache-area management table in which cache-area management information including usage status of the cache area is registered; and a memory control unit configured to acquire a memory area in the cache area having the least amount of write pending data in a pending state for writing in the drive unit by referring to the cache-area management table.

Abstract: A method and apparatus for assigning zone groups to a storage enclosure is disclosed. When a storage enclosure is added to a switch in a fabric, a signature of the storage enclosure will be created from the storage devices loaded in that enclosure. The signature will then be compared against the signature from a storage enclosure that is offline. When the signature matches the signature of the offline storage enclosure, the zone groups from the offline storage enclosure will be copied to the storage enclosure that was added to the fabric.

Abstract: A memory controller (MC) is associated with a remapping table to enable access to content in a memory system that includes asymmetric memory. The MC receives a request for a memory read or an Input/Output (I/O) write from a central processing unit (CPU) for a physical address specified by the system's memory management unit (MMU). The CPU uses the MMU to manage memory operations for the CPU, by translating the virtual addresses associated with CPU instructions into physical addresses representing system memory or I/O locations. The MC for asymmetric memories is configured to process the MMU-specified physical addresses as an additional type of virtual addresses, creating a layer of abstraction between the physical address specified by the MMU and the physical memory address with which that address is associated by the MC. The MC shields the CPU from the computational complexities required to implement a memory system with asymmetric components.

Abstract: Systems, methods, and apparatus for facilitating dynamic provisioning of a virtual storage appliance in a cloud computing environment are presented herein. A storage system management component can provision storage from a storage medium to facilitate access of at least a portion of the storage by a virtual storage appliance (VSA) based on a request for at least one resource associated with the VSA. Further, a network management component can provision the VSA to facilitate the access of the portion of the storage by the VSA. Furthermore, a storage fabric management component can configure a network to facilitate the access of the portion of the storage by the VSA via the network.

Abstract: A multi-later memory and method for operation is disclosed. The memory includes three or more layers, where each layer is made up of flash memory cells having a greater bit per cell storage capacity than then prior layer. The method may include the steps of directing host data directly into a first or second layer of the multi-layer memory upon receipt depending on a condition of the data. The method may also include copying data within a respective layer in a data relocation operation to generate more free blocks of memory so that data preferably stays within each layer, as well as transferring data from one layer to the next higher bit per cell layer when layer transfer criteria are met.

Abstract: Embodiments of the present invention provide an approach to provision storage resources (e.g., across an enterprise storage system (ESS) such as a general parallel file system (GPFS) or the like) for different workloads in an energy efficient manner. The system evaluates different energy profiles/workloads' energy consumption characteristics of storage devices to determine an allocation plan that reduces the energy cost (e.g., results in the lowest cost/energy consumption for handling a storage workload). In a typical embodiment, energy consumption characteristics for handling a particular storage workload will be determined. Thereafter, a type of storage device capable of handling the workload will be determined. Then, an allocation plan that results in the most efficient energy consumption for handling the workload will be developed. In general, the allocation plan is based upon the energy consumption characteristics and an energy efficiency algorithm.

Abstract: Read completion buffer space is allocated in accordance with a preset limit. When a read request is received from a client, the sum of a current allocation of the read completion buffer space and a new allocation of the read completion buffer space required by the read request is compared with the preset limit. If the preset limit is not exceeded, read completion buffer space is allocated to the read request. If the preset limit is exceeded, the read request is suspended until sufficient data is read out from the read completion buffer.

Abstract: If a monitor measurement cycle is set as a long cycle, promotion in a short cycle cannot be performed; and even if the number of I/Os is very large in response to fluctuations of the number of I/Os in several minutes to several hours of normal work, pages will be promoted after waiting for several weeks. As a result, I/Os which could have normally accepted by an upper tier will be accepted by a lower tier, which results in a problem of worsening the performance efficiency. A monitoring system capable of preventing demotion due to temporary reduction of the number of I/Os for specific pages from a viewpoint of a long cycle and enabling prompt promotion in response to an increase of the number of U/Os for 3 the specific pages is realized. A load index value defined from a viewpoint of a long cycle and a load index value defined from a viewpoint of a short cycle are updated based on the number of I/Os which is counted cyclically for each storage area.

Abstract: The disclosed embodiments provide a system that uses unused bits in a memory pointer. During operation, the system determines a set of address bits in a address space that will not be needed for addressing purposes during program operation. Subsequently, the system stores data associated with the memory pointer in this set of address bits. The system masks this set of address bits when using the memory pointer to access the memory address associated with the memory pointer. Storing additional data in unused pointer bits can reduce the number of memory accesses for a program and improve program performance and/or reliability.

Abstract: The present invention achieves data relocation in accordance with a user's policies, in an environment where a plurality of storage devices coexist. The volumes belonging to storage devices A-D are managed virtually integrally. A host recognizes a plurality of storage devices A-D as a single virtual storage device. The user is able to group arbitrarily each volume belonging to the storage system, as a plurality of storage layers 1-3. For example, storage layer 1 can be defined as a high-reliability layer, storage layer 2, as a low-cost layer, and storage layer 3, as an archive layer. Each storage layer is constituted by a group of volumes corresponding to respective policies (high reliability, low cost, archiving). The user designates volumes V1 and V2 to be moved, in group units, and indicates a storage layer forming a movement destination, whereby the data is relocated.