Abstract: A memory that includes a data partition and an index partition is mounted. The data partition includes an original data and an original index written directly after the original data. The index partition includes the original index at the beginning of the index partition. The first data is written to a data partition of the memory. The first data is written directly after the at least one data on the data partition and the original index is deleted and invalidated. Responsive to a time interval elapsing, a first index is written to the data partition of the memory directly after the first data. The time interval starts at the writing of the first data. Responsive to the time interval elapsing, the first index is written to the index partition of the memory at the closest location, in terms of movement time, to the first index on the data partition.

Abstract: A method, device and non-transitory computer readable medium that manages read access includes organizing a plurality of requests for objects on one or more storage media, such as tapes or spin-down disks, based on at least a deadline for each of the plurality of requests. One of one or more replicas for each of the objects on the one or more storage media is selected based on one or more factors. An initial schedule for read access is generated based at least on the deadline for each of the plurality of requests, the selected one of the replicas for each of the objects, and availability of one or more drives. The initial schedule for read access on the one or more of the drives for each of the plurality of requests for the objects is provided.

Abstract: Managing a file on a tape. In response to a request to write a first file to a tape, whether a second file including data identical to the first file already exists on the tape is detected. If the second file exists, a first index of the second file is updated. After completing the write of the first file, metadata, including data starting position and size of the first file, is added to the first index. In response to a request to read the first or second files, the metadata of the first and second indexes are read. Based on the metadata, which of the first or second files can be accessed faster from a current head position is determined. The first file or the second file that can be accessed faster is then read from the tape.

Abstract: In one embodiment, the present disclosure describes a method of optimizing memory access in a hierarchical memory system. The method includes determining a request rate from an ith layer of the hierarchical memory system for each of n layers in the hierarchical memory system. The method also includes determining a supply rate from an (i+1)th layer of the hierarchical memory system for each of the n layers in the hierarchical memory system. The supply rate from the (i+1)th layer of the hierarchical memory system corresponds to the request rate from the ith layer of the hierarchical memory system. The method further includes adjusting a set of computer architecture parameters of the hierarchical memory system or a schedule associated with an instruction set to utilize heterogeneous computing resources within the hierarchical memory system to match a performance of each adjacent layer of the hierarchical memory system.

Abstract: A storage control apparatus includes a processor. The processor is configured to store, during a normal operation mode, first data as a first logical volume in a storage section of a first virtual storage device. The first data is transmitted and received between a first host device and a physical storage device. The physical storage device stores data in a physical volume. The first virtual storage device is connected to the physical storage device during the normal operation mode. The processor is configured to serve, during a data migration mode, as a pseudo host device connected to a second virtual storage device. The pseudo host device accesses the second virtual storage device to read out second data of a second logical volume stored in the second virtual storage device. The first virtual storage device is connected to the second virtual storage device during the data migration mode.

Abstract: The time required for recalling the file is reduced when the file is written in a mounted plurality of tapes in comparison to recalling the file when written in a non-mounted plurality of tapes. In the non-mounted state, criteria does not typically exist in order to recall the written file within the plurality of tapes. Embodiments of the present invention provide systems and methods for recalling files based on criteria which considers: the mounted state of a tape; the type of tape; the type of available tape drive; the number of files included in a tape; and the location of the written file in a tape.

Abstract: According to one embodiment, a semiconductor device includes an input/output circuit. An input/output circuit includes first to third circuits. The first circuit transmits one of first to third data to the second circuit. The second circuit outputs the data, in a first-in-first-out (FIFO) format. The third circuit transmits first clock signal to the first circuit when the first circuit outputs one of the first and second data. When the one of the first and second data is read, the second circuit receives the one of the first and second data in response to the first clock signal within a period until a first signal is received. When the third data is read, the second circuit receives the third data in response to a second clock signal within the period.

Abstract: An approach for object storage power consumption optimization in a networked storage environment is provided. In a typical embodiment, a plurality of memory devices are organized into pods into which redundantly replicated objects are intelligently placed. At least one pod is activated in a read-write configuration, such that data written to the networked storage environment is written to this pod. At least one other pod is a deactivated pod, which has at least one designated memory device in a read-only configuration and a remainder of devices in a deactivated state. Requests for data contained in this deactivated pod are serviced by the designated memory device in the read-only configuration. In some embodiments, the activated and deactivated pods are rotated based on an event.

Abstract: The present invention relates to a kernel state and user state data exchange method for disaster recovery of a virtual container system. In one disaster recovery backup of a virtual container, data needs to be exchanged between a kernel state and a user state. The file system operation of the kernel state needs to be transmitted to a user state program for processing firstly, and the processing result is returned to the kernel state and then transmitted to an original application program. Low recovery speed of a data block is mainly caused by the need of multiple times of switching between the kernel state and the user state, and the communication efficiency of the kernel state and the user state is low. In the present invention, all recovery operations are completed by the user state by virtue of a FUSE.

Abstract: In a general embodiment, a method includes storing hierarchically-organized global configuration information for each node and each tape library resource in a storage cluster to at least one memory accessible by each node of the storage cluster, the storage cluster comprising at least one tape library. The method further includes migrating and/or recalling, using the hierarchically-organized global configuration information, data to and/or from a tape cartridge pool within a tape library. The migration or recall is performed by an appropriate node of the storage cluster and in response to receiving a migration or recall request at an arbitrary node of the storage cluster.

Abstract: A computer program product for migrating data in a computer storage system. Data is selected to migrate from a first storage to the second storage, wherein selected files are in a resident state. Metadata is obtaining and subsets of data are ordered based on the obtained metadata, the order of the subsets of data following an expectation of update value. The subsets of data are transferring to the second storage based on the order of the subsets of data based on a predetermined schedule. Data determined as inactive is overwritten on the sequential access medium by transferred data. End data to the sequential access medium is set after a last active data is written before the one or more sets of data are determined to be inactive. The one or more sets of data determined to be inactive are deleted from the second storage and a transfer is initiated.

Abstract: A computer system for migrating data in a computer storage system. Data is selected to migrate from a first storage to the second storage, wherein selected files are in a resident state. Metadata is obtaining and subsets of data are ordered based on the obtained metadata, the order of the subsets of data following an expectation of update value. The subsets of data are transferring to the second storage based on the order of the subsets of data based on a predetermined schedule. Data determined as inactive is overwritten on the sequential access medium by transferred data. End data to the sequential access medium is set after a last active data is written before the one or more sets of data are determined to be inactive. The one or more sets of data determined to be inactive are deleted from the second storage and a transfer is initiated.

Abstract: A plurality of arrays of storage devices, each providing dual storage device redundancy, is provided. The plurality of arrays of storage devices includes a plurality of mirrored sets of primary storage devices, each including an even number of at least two or more primary storage devices. Each of the mirrored sets of primary storage devices stores a first and a second copy of data. The plurality of arrays of storage devices also includes a secondary storage device, which is a single physical storage device that stores a third copy of the data stored on each of the plurality of mirrored sets of primary storage devices. The secondary storage device has at least the capacity to store the data stored on the plurality of mirrored sets of primary storage devices. Dual storage device redundancy preserves data if data cannot be read from one or two physical storage devices in any array.

Abstract: The disclosed embodiments provide a system that processes data. During operation, the system uses a first key to protect a write operation on the data. Next, the system uses a second key to protect a read operation on the data.

Abstract: A distributed storage system has multiple instances. There is a plurality of local instances, and at least some of the local instances are at physically distinct geographic locations. Each local instance is configured to store data for a non-empty set of blobs in a plurality of data stores having a plurality of distinct data store types. In addition, each local instance stores metadata for the respective set of blobs in a metadata store distinct from the data stores. There is also a plurality of global instances. Each global instance is configured to store data for zero or more blobs in zero or more data stores and store metadata for all blobs stored at any local or global instance. The system selects one global instance to run a replication module that replicates blobs between instances according to blob policies. Some systems also include dynamic replication based on user needs.

Abstract: Managing a file on a tape. In response to a request to write a first file to a tape, whether a second file including data identical to the first file already exists on the tape is detected. If the second file exists, a first index of the second file is updated. After completing the write of the first file, metadata, including data starting position and size of the first file, is added to the first index. In response to a request to read the first or second files, the metadata of the first and second indexes are read. Based on the metadata, which of the first or second files can be accessed faster from a current head position is determined. The first file or the second file that can be accessed faster is then read from the tape.

Abstract: Managing data stored in at least one data storage device (DSD) of a computer system where the at least one DSD includes at least one disk for storing data. A Linear Tape File System (LTFS) write or read command is generated including an LTFS block address. The LTFS block address is translated to a device address for the at least one DSD and data on a disk of the at least one DSD is written or read at the device address.

Abstract: A storage controller includes a reconstruction unit that reconstructs data of a storage device to be restored among the plurality of storage devices by using data read from redundant storage devices other than the storage device to be restored among the plurality of storage devices, and stores the reconstructed data into a first backup storage device among the plurality of backup storage devices, and a copy unit that copies the data read from the redundant storage devices into second backup storage devices assigned to the redundant storage devices from among the plurality of backup storage devices during reconstruction by the reconstruction unit.

Abstract: Reducing time required to write a file to tape is provided. Synchronous processing is performed in a file system implementing a Linear Tape File System (LTFS) file format, wherein the synchronous processing includes writing, to a tape medium of a tape cartridge, index information and one or more files. A type of the synchronous processing is determined, wherein the type is either an index-MAM sync type or an index-only sync type. Updated information is stored to a media auxiliary memory of the tape cartridge in response to determining that the synchronous processing is of the index-MAM sync type.

Abstract: The method of the present invention includes the steps of: receiving a command for creating a snapshot of the logical volume; preparing a management table for managing the snapshot; detecting the storage status of the logical volume; and updating the management table without recalling the logical volume from the second level storage to the first level storage when the logical volume has migrated from the first level storage to the second level storage. After the update, the storage table indicates whether creation of a snapshot is required, whether a logical volume has migrated, and whether the second level storage is the storage location of the logical volume.

Abstract: Emulating tape data includes providing a first storage device coupled to a host, providing a tape emulation unit coupled to the host, the tape emulation unit including a data mover, and, in response to a command to transfer data between the first storage device and the tape emulation unit, transferring data directly between the first storage device and the data mover using a link therebetween, where data that is transferred bypasses the host. The tape emulation unit may include a front end component coupled to the host and a second storage device, the data mover being interposed between the second storage device and the front end component. The front end component may be coupled to the data mover using a GigE switch. The data mover may use NFS to access data. At least one of the first and second data storage devices may be data storage arrays.

Abstract: A first data store controlled by an item providing system is searched for an electronic version of a publication. A second data store is searched for a physical version of the publication. Publication search results are received from the first data store and the second data store, the publication search results indicating whether the electronic version of the publication is available from an electronic location, whether the physical version of the publication is available at a physical location, and the physical location at which the physical version is available.

Abstract: A method of operating a data storage system includes writing the file system data as sequential data and non-sequential data to a storage volume, the sequential data being stored in windows each having a predetermined number of consecutive data blocks and being allocated dynamically as the sequential data is written. The method includes maintaining and using a window cache to identify existing windows for storing respective newly written sequential file system data in sequence with respective earlier-written file system data for which the existing windows were previously allocated, the window cache including a set of entries indexed by an identifier of (1) a file of the file system and (2) a window-size region of the file to which sequential data is being written, the entries including respective physical window addresses identifying respective ones of the existing windows and being obtained by lookup operations using respective values of the identifier.

Abstract: A storage controller out of a plurality of storage controllers used in a storage system, each of the plurality of storage controllers being configured to control mirror processing of data, the storage controller comprising: circuitry configured to: determine a storage controller of a destination of an input and output request for a volume, out of the plurality of storage controllers, based on mirror device information where identifiers and priorities of the respective storage controllers are stored while being associated with each other for each of mirror processing units, and state information being for each of storage controllers and indicating whether the storage controller is normal or not, and issue the input and output request to the determined storage controller.

Abstract: A tape recording device, method, and computer program product are provided for performing operations of position movement, reading, and writing on a tape medium, and receiving a series of commands from an upper-layer device. The tape recording device includes a buffer for temporarily storing data related to the reading and an append write, a tape for recording the data stored in the buffer, a reading and writing head for reading data from the tape into the buffer and writing the data onto the tape, control means for reading data from a designated position of the tape and storing the data in the buffer, and for writing the data stored in the buffer onto the tape from a written data end position in response to an append write command, and a non-volatile memory for storing data stored in the buffer in response to an append write command.

Abstract: A method for writing data from a table to a tape includes setting a number of partitions on the tape, where the number of partitions is greater than or equal to a number of columns of the table to be written to the tape, and writing data from each column of the table to at least one partition of the tape, the at least one partition including two or more wraps, the data is written from a top of the two or more wraps towards a bottom of the two or more wraps in a direction of a width of the at least one partition. The written data is reciprocated from a beginning of the tape to an end of the tape in a longitudinal direction of the tape such that writing of a last data entry of one column ends at a beginning of the two or more wraps.

Abstract: A method of and system for gate-level masking of secret data during a cryptographic process is described. A mask share is determined, wherein a first portion of the mask share includes a first number of zero-values and a second number of one-values, and a second portion of the mask share includes the first number of one-values and the second number of zero-values. Masked data values and the first portion of the mask share are input into a first portion of masked gate logic, and the masked data values and the second portion of the mask share are input into a second portion of the masked gate logic. A first output from the first portion of the masked gate logic and a second output from the second portion of the masked gate logic are identified, wherein either the first output or the second output is a zero-value.

Abstract: Remote computing resource service providers allow customers to execute one or more applications in a virtual environment on computer systems provided by the computing resource service provider. The virtual machines may be managed by a hypervisor executing on computer systems operated by the service provider. The virtual machines' memory may be protected by a memory obfuscation service and the hypervisor. The memory obfuscation service may enable the virtual machines to maintain at least a portion of sensitive information in an obfuscated format. The virtual machines may request access to the virtual machines' memory, the memory obfuscation service may obtain the requested memory in an obfuscated format and un-obfuscate the memory such that it may be used by the virtual machines.

Abstract: A request to access a virtual tape volume is identified and a lock status is maintained for the virtual tape volume. The lock status includes a shared status and an exclusive lock status. In shared status, it is determined whether the request includes a request for write access to the virtual tape volume. Concurrent access to the virtual tape volume can be allowed by two or more applications during the shared status based at least in part on whether the applications request for write access to the virtual tape volume.

Abstract: Methods, apparatus and computer program products implement embodiments of the present invention that include defining, in a storage system including multiple storage devices, multiple redundant array of independent disks (RAID) configurations for data stored on the storage devices. A first one of the multiple RAID configurations is assigned to a first entry in a partition table having multiple entries. Assigning the first one of the multiple RAID configurations to the first entry in the partition table comprises modifying an existing RAID configuration for the first entry. Data referenced by the existing RAID configuration is migrated to the modified RAID configuration.

Abstract: A graphical representation of available Storage Area Networks (SANs) and of available hosts is displayed. Storage is provisioned from a selected SAN to a selected host in response to dragging and dropping the graphical representation of the selected SAN into the graphical representation of the selected host. Thus, a drag-and-drop metaphor may be used to facilitate storage provisioning. Related methods, systems and computer program products are disclosed.

Abstract: Methods, computing systems and computer program products implement embodiments of the present invention that include initializing, by a processor executing a file system in communication with a block manager managing multiple storage regions on a storage device, a file system write cache to have a default cache size, the default cache size corresponding to a first storage capacity of a default number of the storage regions. Upon detecting that a current number of the storage regions that are not in use by the block manager is less than the default number, the file system write cache is resized to a reduced cache size that corresponds to a second storage capacity of the current number of the storage regions. While the file system write cache has the reduced cache size, the file system write cache can be resized back to the default cache size as unused storage regions become available.

Abstract: Systems, methods, and firmware for power control of data storage devices are provided herein. In one example, a data storage device is presented. The data storage device includes a storage control system to identify a power threshold for the data storage device. The data storage device determines power consumption characteristics for the data storage device and enters into a power controlled mode for the data storage device that adjusts at least a storage transaction queue depth in the data storage device to establish the power consumption characteristics as below the power threshold for the data storage device.

Abstract: Data is relocated, based on an intelligent data placement algorithm, from a first storage location to a second storage location in a disk storage system. A data placement record is generated including a virtual disk location associated with the data, the second storage location, and a first sequence value. The first sequence value indicates relative sequence when compared to other sequence values. The data placement record is written to a first record location on a first tape cartridge loaded in a tape drive. The data placement records are used with data records to restore data to disk storage from tape backup.

Abstract: A method and a system for data migration are described, the method for data migration including: slicing data in an original system to obtain a data slice; importing the data slice into a new system; and redoing, in the new system, respective data corresponding to at least one pre-recorded write request according to a sequence number order of the at least one pre-recorded write request, wherein the at least one pre-recorded write request above is to simultaneously write to both the original system and the new system. In the method and the system, data in an original system can be seamlessly imported to a new system without forbidding writes to the original system, and the data in the new system can be recovered to the latest by a redo technique. Without any awareness of users, the data migration can be achieved in the background.

Abstract: A memory system having a plurality of modules operated so that a group of memory modules may operation in a RAID configuration having an erase hiding property. The RAID groups are mapped to areas of memory in each of the memory modules of the RAID group. More than one RAID group may be mapped to a memory module and the erase operations of the RAID groups coordinated such that the erase operations do not overlap. This may improve the utilization of a bus over which the memory module communicates with the controller. Where a memory module is replaced by a memory module having an increased storage capacity, the additional storage capacity may be mapped to an expanded logical address space.

Abstract: A virtual tape device includes a determination unit and a copy creation unit. The determination unit determines, when deleting some logical volume data among a plurality of logical volume data stored on a first physical tape, whether to conduct copy processing to store a copy of the logical volume data onto a second physical tape on the basis of a storage location of the logical volume data. The copy creation unit stores, when it is determined to conduct the copy processing, a copy of the logical volume data on the second physical tape so as to cause spacing between a storage location of the logical volume data on the second physical tape and a head location on the second physical tape to become shorter than spacing between a storage location of the logical volume data on the first physical tape and a head location on the first physical tape.

Abstract: Provided are a method, system, and computer program product for determining a metric to use to determine whether to generate a low space alert. A determination is made of provisioned storage space comprising storage space allocated to at least one application, wherein applications may use less than all the provisioned storage space. A determination is made of available storage space comprising all installed storage space available for use by the at least one application having allocated storage space. A determination is made of allocated storage space comprising storage space used by the applications. A determination is made of an allocation metric as a function of the provisioned storage space, the allocated storage space, and the available storage space. The determined allocation metric is used to determine whether to generate a storage space related alert.

Abstract: Embodiments relate to a computer system for storing data on a time multiplexed redundant array of independent tapes. An aspect includes a memory device that buffers data received by the computer system to be written to a set of tape data storage devices. The data is written to the set of tape data storage devices in blocks that form parity stripes across the set of tape data storage device. Aspects further includes a tape drive that writes data to one of the set of tape data storage devices at a time in a tape-sequential manner and a processor that computes a parity value for each of the parity stripes. The tape drive writes the parity values for each of the parity stripes to a last subset of tapes of the set of tape data storage devices.

Abstract: A file processing method and a storage device for storing a file in a redundant array of independent disks (RAID) are disclosed. In this method, the storage device divides received F files into multiple data blocks, and obtains a first matrix with T rows according to the multiple data blocks. Data blocks belonging to one file are located in one row of the first matrix. The storage device then writes a stripe, which consists of data blocks in each column in the first matrix and a check block that is obtained by computing according to the data blocks in the column, into the RAID. By using the file processing method, the storage device can write one file into one disk of the RAID while ensuring security of file storage, thereby achieving a better energy saving effect when the file is read.

Abstract: Provided are a computer program product, system, and method for assigning device adaptors to use to copy source extents in source ranks to target extents in target ranks in a copy relation. A determination is made of an order of the target ranks in the copy relation. Target ranks in the copy relation are selected according to the determined order. For each selected target rank, indication is made in a device adaptor assignment data structure of a source device adaptor and target device adaptor of the device adaptors to use to copy the source rank to the selected target rank indicated in the copy relation, wherein indication is made for the selected target ranks according to the determined order. The source ranks are copied to the selected target ranks using the source and target device adaptors indicated in the device adaptor assignment data structure.

Abstract: Aspects of the disclosure are direct towards managing data overlay in a direct access storage device (DASD) using metadata of data stored within the DASD. The DASD receives user input. The user input includes a value indicating activation of overlay tracking for a track of the DASD. The DASD updates the metadata to indicate overlay tracking activation. The DASD detects a write request from an application to overlay data on the track. In response to overlay tracking being activated for the track, the DASD determines the access method used to transmit the write request. The DASD determines an identifier for the application. The DASD determines the identifier using the protocol of the access method. The DASD records data regarding the write request within the metadata. In response to recording the data regarding the write request, the DASD overlays the track per the write request.

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: An integrated circuit may comprise a processor, a first level instruction cache having a first storage capacity, and a second level cache having a second storage capacity that is larger than the first storage capacity. The first level instruction cache is configured to store a subset of instructions stored in the second level cache. The second level cache is configured to store a subset of data and instructions stored in an external memory. The processor executes an inner loop of a detection routine and monitors an execution time of the inner loop to detect malicious code in the first level instruction cache. A total number of detection routine instructions is larger than the first storage capacity. The inner loop requires fetching of detection routine instructions from the second level cache, and an execution number of instructions executed during execution of the inner loop is smaller than the first storage capacity.

Abstract: An approach for providing power utilization information for one or more operational states of an application across different operating systems is described. A power utilization platform determines power utilization information for one or more operational states of an application, one or more operating systems in which the application executes, or a combination thereof. The power utilization platform further stores the power utilization information as metadata associated with a record of the application in a data repository associated with an application distribution service. The power utilization information is then presented in a user interface of the application distribution service in a response to a request to view the record of the application.

Abstract: In an approach for writing data on a tape using a file system, a processor receives a first write request of a first file. A processor obtains data of the first file. A processor writes the data of the first file on a tape. A processor receives a second write request of a second file prior to completion of writing the data of the first file on the tape. A processor adds information about the second file to a first list, wherein the first list includes files waiting to write. Subsequent to writing the data of the first file on the tape, a processor obtains data of the second file based on the first list. A processor writes the data of the second file after the first file on the tape.

Abstract: Moving previous version data required to be restored beyond a continuous data protection window, if required, to facilitate efficient reclamation and reallocation of storage allocated to a continuous data protection journaling process is disclosed. In some embodiments, storage is allocated when possible in an allocation group that enables a continuous data protection or other backup process to perform a series of successive write operations without requiring that a write head be moved inefficiently to many arbitrary points on the storage media.

Abstract: In one embodiment, a computer-implemented method includes executing firmware including a command list configured to maintain commands executable by a host processor of a field-programmable unit. One or more of the commands define communications between the host processor and one or more back-end processors of the field-replaceable unit. The command list includes both periodic commands representing periodic processes and non-periodic commands representing non-periodic processes. Each command in the command list is set to one of active mode and inactive mode. Executing the firmware includes cycling through the command list, and executing, by the host processor, only the commands in the command list that are set to active mode while cycling through the command list.

Abstract: In one embodiment, a computer-implemented method includes executing firmware including a command list configured to maintain commands executable by a host processor of a field-programmable unit. One or more of the commands define communications between the host processor and one or more back-end processors of the field-replaceable unit. The command list includes both periodic commands representing periodic processes and non-periodic commands representing non-periodic processes. Each command in the command list is set to one of active mode and inactive mode. Executing the firmware includes cycling through the command list, and executing, by the host processor, only the commands in the command list that are set to active mode while cycling through the command list.

Abstract: An input/output (I/O) request is dispatched. A determination is made regarding a storage volume to service. A determination is made regarding whether an actual disk throughput exceeds a first threshold rate. The first threshold rate exceeds a reserved disk throughput. Responsive to determining that the actual disk throughput exceeds the first threshold rate, a first storage volume is selected based on credits or based on priority. Responsive to determining that the actual disk throughput does not exceed the first threshold rate, a second storage volume is selected based on guaranteed minimum I/O rate. An I/O request queue associated with the determined storage volume is determined. An I/O request is retrieved from the determined I/O request queue. The retrieved I/O request is sent to a persistence layer that includes the selected storage volume.