Abstract: Described embodiments provide systems and methods for online system recovery orchestration. Embodiments may include receiving a request to recover a system management process from a checkpoint. The system management initialization parameter file is updated by setting a flag to start from the checkpoint. A system management process is started with the updated initialization parameter and a copy of the system management repository is loaded. Volumes are recovered before data path module activation. Data modules are then activated with checkpoint offset information and data module journals are reformatted. Control modules are then activated with recovered volume configuration and control module journals are reformatted. Defragmentation mode is set to rollback mode and data on checkpoint stripes that were written after checkpoint creation are deleted. After waiting for the defragmentation rollback to complete the host IO direction is set to checkpoint stripes.

Abstract: Methods and apparatus for a content-based deduplicated storage system for generating an address to hash (A2H) value for a control module as data blocks are received and generating, for a data module, hash to physical (H2P) values corresponding to the A2H values. A first cache can be provided for the control module, where the first cache can comprise an address value, a hash value, and physical location information. A second cache can be provided for the data module, where the second cache can comprise a bucket value, a hash value, and a filter mechanism, where the filter mechanism is configured to determine whether the hash value is present.

Abstract: A storage system in one embodiment comprises a plurality of storage devices and a storage controller. The storage controller is configured to receive a plurality of logical addresses. Each logical address has one of a content-based mapping type and an address-based mapping type. Responsive to a first logical address of the plurality of logical addresses having the content-based mapping type, the storage controller is configured to utilize a content-based mapping generated based on content of a data page associated with the first logical address to identify a corresponding physical address. Responsive to a second logical address of the plurality of logical addresses having the address-based mapping type, the storage controller is configured to utilize an address-based mapping generated based on the second logical address to identify a corresponding physical address.

Abstract: A storage system in one embodiment comprises a plurality of storage devices configured to store user data pages and metadata pages. Each of the user data pages has a logical address and a content-based signature derived from content of that data page, and each of the metadata pages characterizes a plurality of the user data pages and associates the content-based signatures of those user data pages with respective physical blocks in the storage devices. In conjunction with release of logical address space in the storage system, the released logical address space is made available to users in a first order based at least in part on released logical address, and multiple dereferencing operations are accumulated for respective ones of the physical blocks corresponding to the released logical address space. The accumulated dereferencing operations for the physical blocks are executed in a second order that differs from the first order.

Abstract: An apparatus in one embodiment comprises at least one processing device comprising a processor coupled to a memory. The processing device is configured to capture metadata from a metadata area of a storage system for checkpointing, and to store the captured metadata as checkpointed metadata in a user data area of the storage system in association with mapping information relating portions of the checkpointed metadata to particular storage locations in the user data area. The processing device in some embodiments is implemented within the storage system, and may comprise a storage controller of the storage system. The mapping information illustratively comprises a plurality of page location arrays each having a plurality of entries specifying respective locations of checkpointed metadata pages in the user data area.

Abstract: An apparatus in one embodiment comprises a storage system having a plurality of storage devices and an associated storage controller. The storage devices are configured to provide a metadata area and a user data area, the user data area being separated into pages. The storage controller is configured to initiate generation of one or more checkpoints in the storage system. In conjunction with the generation of a given one of the one or more checkpoints in the storage system, the storage controller causes checkpointed metadata from the metadata area to be stored in the user data area. The storage controller further stores mapping information relating portions of the checkpointed metadata to respective pages of the user data area that store those portions of the checkpointed metadata. The mapping information illustratively comprises page location arrays and array location arrays, and in some embodiments further comprises one or more higher-level location arrays.

Abstract: A computer-implemented method is provided for a storage system comprising a processor in operable communication with a storage device that is configured into a plurality of respective regions of storage space. A first defragmentation process is performed on at least a first region of the plurality of respective regions of storage space to free a first portion of storage space in the a respective first region, where the freed first portion is reserved for user data and metadata associated with I/O requests to the storage system that are generated during a first operation running on the storage system. The storage system is configured to ensure that, during the first operation, user data and metadata are routed towards the first freed portion and kept separate from a set of system checkpoint information, associated with a first state of the storage system, stored in a protected portion of storage space.

Abstract: A computer program product, system, and method for generating coded fragments comprises receiving, at a first node of a distributed storage system, an I/O request to write a block; splitting the block into a plurality of sub blocks; generating a sub block error detection hash for each of the sub blocks; sending the block and the sub block error detection hashes to a second node within the distributed storage system; and storing the block and the sub block error detection hashes to a storage device at the second node.

Abstract: A system, computer program product, and computer-executable method of managing parity data of a Redundant Array of Independent Disks (RAID) on a data storage system, where the data storage system stores a first set of parity data and retains metadata associated with the first set of parity data, the system, computer program product, and computer-executable method including allocating a set of locations on the data storage system for a second set of parity data, processing the second set of parity data, and updating the metadata associated with the first set of parity data.

Abstract: A system, computer program product, and computer-executable method of implementing a redundant array of independent disk (RAID) system wherein the RAID, the computer-executable method comprises storing data storage blocks arranged in a first plurality of data rows and a second plurality of data columns and storing parity data in defined parity blocks, wherein a portion of the defined parity blocks include column parity data.