Abstract: Determining and using deduplication estimates may include: determining two deduplication sample indexes (DSIs) for two logical device sets each including one or more logical devices, determining a Jaccard Similarity for the two DSIs, wherein the Jaccard Similarity denotes a measurement of similarity and mutual deduplication between the two logical device sets; determining, in accordance with one or more criteria, whether the two logical device sets should be located in different data storage systems or a same data storage system that performs data deduplication, wherein the one or more criteria uses the Jaccard Similarity in determining whether to locate the two logical device sets in the same data storage system or the different data storage systems; and responsive to determining that the two logical device sets should be located in the same data storage system, locating the two logical device sets in the same data storage system.

Abstract: A storage control device, includes a processor configured to: dispose original blocks to which data on an object basis is divided and assigned and copy blocks which are copies of the original blocks respectively alternately in storage devices of a distributed storage system in a distributed manner; determine, upon reception of a read request for an object, as a first storage control device out of the storage control devices a read task which collectively reads the original blocks and the copy blocks which belong to the object from one of the storage devices; notify the storage control devices of the read task; upon reception of the read request as the first storage control device, collectively read the original blocks and the copy blocks; and transfer the data of the blocks which have been read to a second storage control device which is the read task for the blocks.

Abstract: A storage system, host, and method for extended and imaginary logical-to-physical address mapping are provided. In one embodiment, a host maps logical block addresses of a plurality of random data to a sequential set of imaginary logical addresses that extend beyond a logical capacity of a memory in a storage system. The host sends a request to the storage system to write the plurality of random data in the sequential set of imaginary logical addresses. Other embodiments are provided.

Abstract: An apparatus (e.g., a content addressable memory system) can have a controller, a first content addressable memory coupled to the controller, and a second content addressable memory coupled to the controller. The controller can be configured to cause the first content addressable memory to write data in the first content addressable memory, cause the second content addressable memory to write the data in the second content addressable memory, and cause the second content addressable memory to query the data written in the second content addressable memory while the first content addressable memory continues to write the data in the first content addressable memory.

Abstract: Storage devices can be configured to desirably reduce the number of times a zone reset or erasure occur via the use of one or more paired overwrite memory blocks. These storage devices can include a plurality of memory devices with some of these memory devices designated as overwrite memory devices. A controller within the storage device can be configured to direct the storage device to generate one or more subsets within the memory devices such as zones, pair each of subsets with at least one or more overwrite memory devices, store data sequentially within the subset of memory devices, and store any received overwrite data in the overwrite memory devices in chronological order. Data stored within the subsets of memory devices are not erased and instead of being overwritten directly, are instead pointed via a control table to a location in the overwrite memory devices storing the corresponding overwrite data.

Abstract: A protocol for processing write operations may include recording each write operation in a log using a PDESC(page descriptor)-PB(page block) pair. The protocol may be a data commit sequence that assigns ownership to containers of logged writes. Each container may be associated with a particular logical block address (LBA) range of a logical device, where logged writes that write to target addresses in the particular LBA range of the logical device may be included in the container. Ownership of a container may be determined by the initial write operation that is mapped to, and placed into, the container based on the target logical address of the write operation. A container may be allocated in response to the initial write operation of the container. Multiple nodes may independently flush containers of logged operations based on the particular node designated as the current owner of the containers.

Abstract: Peer storage systems share the workload of asynchronously replicating a shared logical storage unit (LSU) to a target system. Peer storage systems (S1 and S2) that synchronously replicate a shared LSU share the workload of asynchronously replicating the shared LSU to a target system (S3) by dividing ownership of the replication cycles in an alternating manner without a strict synchronization of cycles between the peer storage systems. Rather, a given cycle number (e.g., Cycle 1) on S1 may not start and end with a same write operation as a same cycle number (Cycle 1) on S2, such that cycles on S1 (e.g., Cycle 1 and Cycle 2) overlap with cycles having the same number (Cycle 1 and Cycle 2) on S2. S1 may asynchronously replicate to S3 only the cycles it owns, and S2 may asynchronously replicate to S3 only the cycles it owns to S3.

Abstract: A storage system in one embodiment comprises a front-end device and a plurality of storage nodes. A given storage node of the plurality of storage nodes comprises at least one processor and memory. The front-end device is configured to obtain a write operation comprising at least a first data page and to generate a content-based signature based at least in part on the first data page. The front-end device is further configured to compress the first data page and to generate first compression information corresponding to the first data page. The first compression information comprises an indication that the first data page has been compressed. The front-end device is further configured to provide the generated content-based signature, the compressed first data page and the first compression information to the given storage node.

Abstract: According to one embodiment, a storage system includes a first storage including first nonvolatile memories storing data which is corrupted when data is read from the first nonvolatile memories, and a controller which controls the first storage. The controller reads data from a first nonvolatile memory at a first address, and determines that whether the read data is to be written back to the first storage or not.

Abstract: Techniques perform storage management. Such techniques involve: in response to receiving, at a first processor of a storage system, a write request from a host for writing user data, caching the user data in a first cache of the first processor, and generating cache metadata in the first cache, the cache metadata including information associated with writing the user data; sending the user data and the cache metadata to a second cache of a second processor, for the second processor to perform, in the second cache, data processing related to cache mirroring by the second processor; and sending, to the host, an indication of completion of the write request, without waiting for the second processor to complete the data processing. Such techniques can improve system performance such as reducing latency, and shortening length of the I/O handling path of write request.

Abstract: The present disclosure relates to caches, methods, and systems for using an invalidation data area. The cache can include a journal configured for tracking data blocks, and an invalidation data area configured for tracking invalidated data blocks associated with the data blocks tracked in the journal. The invalidation data area can be on a separate cache region from the journal. A method for invalidating a cache block can include determining a journal block tracking a memory address associated with a received write operation. The method can also include determining a mapped journal block based on the journal block and on an invalidation record. The method can also include determining whether write operations are outstanding. If so, the method can include aggregating the outstanding write operations and performing a single write operation based on the aggregated write operations.

Abstract: A solid-state drive configured to store persistent digitally encoded data may operate in an initiator mode. When operating in the initiator mode, the solid-state drive may initiate the generation and issuance of a command or a request for another solid-state drive to carry out a data storage related procedure. The command or request generated by the solid-state drive may be communicated directly to another solid-state drive without the communications passing through an intermediate device, such as a host processor.

Abstract: An apparatus includes a processing device comprising a processor coupled to a memory, with the processing device being configured, in conjunction with synchronous replication of at least one logical storage volume between first and second storage systems, to acquire an address lock for a set of pages of the logical storage volume starting from a particular page of the logical storage volume, to determine content-based signatures for respective pages of the set of pages, to compute an additional signature as a function of the content-based signatures, and to send the additional signature and a pointer to the particular page from the first storage system to the second storage system, so as to permit the second storage system to verify consistency of the set of pages in the second storage system relative to the set of pages in the first storage system. Such operations are repeated for other sets of pages.

Abstract: Examples relate to a processor apparatus, device, method and computer program, to a memory performance controller apparatus, device, method and computer program and to a memory controller apparatus, device, method and computer program. The processor apparatus comprises interface circuitry for communicating with other components of the computer system. The processing circuitry is configured to provide an interface for controlling a memory performance requirement of a data structure stored within a memory of the computer system. The memory performance requirement is a percentile-based memory performance requirement comprising at least a first memory performance requirement valid for a first portion of access operations and a second memory performance requirement valid for a second portion of access operations.

Abstract: A data backup system is provided with: a plurality of devices for main site storage, one device for relay site storage, and one or more devices for backup site storage. While the main site is operating normally, the relay site storage implements synchronized replication of data held by the main site storage and data held by the relay site storage. After the main site has stopped operating normally, the data held by the relay site storage and the data held by the backup site storage are subjected to consistency ensuring replication.

Abstract: In a method for identifying a sub-health OSD in a data storage system, a first OSD receives a write request and replicates that write request to a second OSD. Subsequently, the first OSD sends a report regarding the write request to a management node in the system. The report includes an identifier of the first OSD, an identifier of the second OSD, and health status information of the second OSD. The management node determines, based on the received report, whether the second OSD is in a sub-health state.

Abstract: A computer-implemented method, according to one approach, is for converting an existing storage pool into an intended storage pool in place. The computer-implemented method includes: reordering volume extents in the existing storage pool such that physical rank extents of the volumes align with boundaries between rank extents of the intended storage pool. The ranks in the existing storage pool are also converted from first rank extent sizes to second rank extent sizes. Moreover, in response to converting the ranks in the existing storage pool, for each of the volumes: a temporary pause/lock is performed on a volume segment table (VST) entry which corresponds to the given volume, and the VST entry is populated with a new structure which corresponds to the respective second rank extent size.

Abstract: In order to avoid writing duplicates of blocks of data into a storage platform, any virtual disk within the storage platform may have a de-duplication feature enabled. Or, all virtual disks have this feature enabled. For virtual disks with de-duplication enabled, a unique message digest is calculated for every block of data written to that virtual disk. Upon a write, these message digests are consulted in order to determine if a particular block of data has already been written, if so, it is not written again, and if not, it is written. All de-duplication virtual disks are written to a single system virtual disk within the storage platform. De-duplication occurs over the entire storage platform and over all its virtual disks because all message digests are consulted before a write is performed for any virtual disk. A read for a de-duplication virtual desk reads from the system virtual disk.

Abstract: A storage device includes a nonvolatile memory device, a random access memory that includes a first region and a second region, and a controller that is configured to use the first region of the random access memory as a journal memory for a journal indicating modification of data of the second region, expose a user region of the nonvolatile memory device to an external host device as a first access region of a block unit, and expose the second region of the random access memory to the external host device as both a second access region of the block unit and a third access region of a byte unit.

Abstract: To replicate a source LUN to a different storage system platform, a first storage system transmits a request to replicate a LUN along with attributes for the LUN to a second storage system. The second storage system maps the attributes to attributes used and understood by the platform of the second storage system. The second storage system then creates a destination LUN based on the mapped attributes. Since the destination LUN is created with similar attributes as the source LUN, the destination LUN can store the replicated data of the source LUN while still being accessed and recognized as a LUN by the second storage system. The second storage system also stores any proprietary attributes received from the first storage system so that the proprietary attributes can be supplied to the first storage system to recover the source LUN after a data loss event.