Abstract: A data mirroring control apparatus includes a command distributing unit configured to transmit a first write command to a plurality of mirroring storage devices, the first write command including an instruction for data requested by a host to be written; and a memory lock setting unit configured to set a memory lock on the data requested by the host to be written among data stored in a host memory and configured to release the memory lock on the data after the data with the memory lock is written to the plurality of mirroring storage devices.

Abstract: A storage controller includes a co-access pattern mining unit configured to detect co-access patterns of data co-accessed during a particular time duration and to generate co-access groups including a plurality of pieces of data complying with the co-access patterns. The storage controller further include a co-access group matching unit configured to select a co-access group matched with read-requested data, among the generated co-access groups, and a data placement unit configured to store the data included in the selected co-access group in a pre-fetch buffer.

Abstract: A redundant array of inexpensive disks (RAID) system including nonvolatile memory and an operating method of the same is provided. A nonvolatile memory device implemented as a RAID and including a plurality of first memory chips, which store data chunks, and a second memory chip, in which spare memory regions are defined. A RAID controller controls RAID operations and a rebuild operation of the nonvolatile memory device. The RAID controller monitors a failure probability of each of the first memory chips, and in response to detecting a failure probability of two or more first memory chips that satisfies a predefined threshold value, a first rebuild on data stored in each of the first memory chips is performed to store the data in the second memory chip. A second rebuild on data stored in the first memory chip having the failure using data stored in the second memory chip.

Abstract: A data mirroring control apparatus includes a command distributing unit configured to transmit a first write command to a plurality of mirroring storage devices, the first write command including an instruction for data requested by a host to be written; and a memory lock setting unit configured to set a memory lock on the data requested by the host to be written among data stored in a host memory and configured to release the memory lock on the data after the data with the memory lock is written to the plurality of mirroring storage devices.

Abstract: Provided is a RAID system that includes a memory device including a plurality of nonvolatile memories storing data chunks and first and second parity bits corresponding to the data chunks, a RAID controller configured to control a RAID operation and a rebuild operation of the memory device, and a host configured to communicate with the RAID controller at an input/output (I/O) rate. The RAID controller is configured to perform a first rebuild operation using the first parity bit and a first policy having a first rebuild rate, to perform a second rebuild operation using the first and second parity bits and a second policy having a second rebuild rate, to apply a first sub-rate as the first rebuild rate until the I/O rate reaches a predetermined value, and to apply a second sub-rate as the first rebuild rate when the I/O rate is greater than the predetermined value.

Abstract: An operating method of a memory system including a storage array including a plurality of segments and a first server node and a second server node allocating and managing the plurality of segments includes: requesting, via the first server node, load information from the second server node before performing a memory operation; receiving, via the first server node, the load information from the second server node and comparing load information of the first server node with the load information of the second server node; performing, via the first server node, a load balancing operation, based on a comparison result; and performing, via the first server node, a segment dynamic allocation operation regarding the storage array, the segment dynamic allocation operation matching the load balancing operation.

Abstract: The data storage device includes a separator configured to separate data requested to write by clients into data chunks, an address translator configured to translate first addresses generated by the data chunks into second addresses as global addresses, a storage node mapper configured to map the second addresses to a plurality of storage nodes, and a data store unit configured to select a target storage node among the plurality of storage nodes and store the data chunks in the target storage node. The data chunks include a plurality of data input/output unit blocks. If other data chunks that are the same with the data chunks are pre-stored in the plurality of storage nodes, the data store unit is configured to establish links between the same pre-stored data chunks and the second addresses, rather than stores the data chunks in the plurality of storage nodes.

Abstract: A method of operating a storage device including at least one nonvolatile storage and a storage controller configured to control the nonvolatile storage. A first type of request, original data and a first request information associated with the original data are received, in the storage controller, from an external host device, a compression operation to compress the original data to generate compressed data is performed in the storage controller, in response to the first type of request, and a write operation to write the compressed data in a data storage area of the nonvolatile storage is performed in the storage controller. The data storage area of the nonvolatile storage may store the first request information associated with the original data. The external host may manage mapping information in the form of a mapping table associated with compression/decompression at the storage device.

Abstract: A redundant array of independent disks (RAID) storage system includes a plurality of storage devices that perform an erase operation according to a plurality of erase unit sizes. A RAID controller controls the plurality of storage devices based on a RAID environment. The RAID controller adjusts the erase unit sizes with respect to at least some of the plurality of storage devices, respectively.

Abstract: A cache management apparatus includes an access pattern analysis unit configured to analyze an access pattern of each of one or more pages present in a first cache by monitoring data input/output (I/O) requests, a page class management unit configured to determine a class of each of the pages based on results of the analysis performed by the access pattern analysis unit, and a page transfer management unit configured to transfer one or more pages classified into a first class including pages to be transferred, to a second cache based on results of the determination performed by the page class management unit.

Abstract: A storage controller that improves performance of a storage device by reducing the number of data I/O operations. The storage controller, as part of a storage device and a storage system, and in a method of operating the storage controller, includes a host interface receiving data requested for storage from a host and lifetime information indicating a change period of the data, and a data placement manager determining a storage position of the data in a flash memory based on the lifetime information of the data.

Abstract: A redundant array of independent disks (RAID) storage system, includes a RAID master controller receiving a RAID request selectively communicating the RAID request to one of a plurality of storage devices, wherein first and second storage devices are directly connected outside a data communication path including the host among the storage devices. The first storage device determines upon receiving the RAID request whether distribution of a RAID sub-request to the second storage device is necessary, such that upon determining that the distribution of a RAID sub-request is necessary, the first RAID controller communicates the RAID sub-request to the second storage device via the direct network connection.

Abstract: A stripe reconstituting method in a storage system, a garbage collection method employing the stripe reconstituting method, and the storage system performing the stripe reconstituting method are provided. The stripe reconstituting method includes the operations of selecting a target stripe in which an imbalance between valid page ratios of memory blocks included in the target stripe exceeds an initially-set threshold value, from among stripes produced in a log-structured storage system; and reconstituting a stripe by regrouping the memory blocks included in the target stripe such that the imbalance between the valid page ratios of the memory blocks included in the target stripe is reduced.

Abstract: A virtualization apparatus is provided. The virtualization apparatus includes a plurality of virtual machines (VMs), a process scheduler configured to schedule processes to be executed on the respective virtual machines, a virtual machine monitor (VMM) configured to provide each of the virtual machine with a virtualized execution environment, a virtual machine scheduler configured to schedule the virtual machines to run in the virtual machine monitor, and a synchronization unit configured to synchronize a process schedule time which is scheduled by the process scheduler and a virtual machine schedule time which is scheduled by the virtual machine scheduler, or to change the virtual machine schedule time in consideration of the process schedule time.

Abstract: A data storage device includes a nonvolatile memory arranged in drives and stripes, a buffer storing state information for each of the stripes, and a memory controller including a redundant array of independent disks (RAID) controller that operates in a spare region mode and performs data recovery using garbage collection based on the state information. The state information includes a first state indicating that none of the drives has malfunctioned, a second state indicating one of the drives has malfunctioned, and a third state indicating that data/parity stored in a malfunctioning drive has been recovered.

Abstract: The method of operating a storage system includes executing a storage service providing storage of a volume unit to at least one host device, in which the volume includes a first volume and a second volume. The method includes giving a first priority and a second priority lower than the first priority to the first volume and the second volume, respectively, and recovering meta-data for the first volume having the first priority when the storage service is stopped. The method includes starting the storage service using the recovered meta-data for the first volume, and recovering meta-data for the second volume having the second priority.

Abstract: Processing an adaptive interrupt includes selectively setting an input/output (I/O) device in a computing system to an adaptive masking mode when at least one factor value of the at least one I/O device regarding a workload of the computing system exceeds a first threshold condition. Processing the adaptive interrupt further includes performing an interrupt masking process, where an interrupts generated by an I/O device set to the adaptive masking mode are prevented from being output when a time interval between I/O submission events of the I/O device is less than a first threshold value. The adaptive interrupt may be processed by an adaptive interrupt processing module (AIPM). The AIPM may be included in various portions of the computing system, including the I/O device and a host connected to the I/O device.

Abstract: A mapping table managing method, performed in a storage system, includes organizing mapping information about the storage system into a plurality of pieces of partial mapping table (PMT) information and distributing and storing the plurality of pieces of PMT information in storage devices (SDs). The method includes searching for a storage location in an SD on which an access operation is to be performed, by using the PMT information stored in each of the SDs, and performing the access operation on a found storage location in the SD.

Abstract: A stripe reconstituting method in a storage system, a garbage collection method employing the stripe reconstituting method, and the storage system performing the stripe reconstituting method are provided. The stripe reconstituting method includes the operations of selecting a target stripe in which an imbalance between valid page ratios of memory blocks included in the target stripe exceeds an initially-set threshold value, from among stripes produced in a log-structured storage system; and reconstituting a stripe by regrouping the memory blocks included in the target stripe such that the imbalance between the valid page ratios of the memory blocks included in the target stripe is reduced.

Abstract: Provided are a method of performing garbage collection and a redundant array of independent disks (RAID) storage system to which the method is applied. The method includes selecting a victim stripe for performing the garbage collection in the RAID storage system based on a ratio of valid pages. Valid pages included in the victim stripe are copied to a non-volatile cache memory. Garbage collection is performed with respect to the victim stripe by using data copied to the non-volatile cache memory.