Abstract: Example implementations relate to preserving data availability in a constrained deployment of an HA system (e.g., an HA storage system) in the presence of pending faults. According to an example, a first arbiter, acting as a witness to facilitate maintaining quorum for the HA system, and a first node are provided within a first failure domain; and a second arbiter, serving as a backup arbiter, and a second node are provided within a second failure domain. Responsive to receipt of an indication of a pending fault impacting the first failure domain by a member of the current configuration of the HA system, establishment of a new configuration, excluding the first arbiter and including the second arbiter, is initiated. Responsive to a majority of the current configuration installing the new configuration, the second arbiter is enabled to serve as the active arbiter by transferring state information to the second arbiter.

Abstract: A source system generates snapshots of collected data. The snapshots have respective associated time references. Responsive to a request from a target system for data collected over a time interval, the source system generates a subset of the data collected by determining a start snapshot and an end snapshot. The start snapshot and the end snapshot are determined as a pair of snapshots that have respective associated time references that are most closely spaced and are inclusive of the time interval. The source system determines a difference in the data included in the end snapshot and the start snapshot and provides the subset of the data as the difference in the data included in the end snapshot and the start snapshot.

Abstract: Cluster groups define a relationship between clusters in an HCI system. New cluster groups may be created, and a cluster may be added or removed from an existing cluster group. A method and system are disclosed to support a dynamically scaled hyperconverged system with non-overlapping and overlapping cluster groups. A dynamically scalable hyperconverged system may allow for piece-wise upgrades while supporting inter-operable and non-interoperable components having a secure intercommunication capability. A system is disclosed for scaling a single managed hyperconverged infrastructure (HCI) where all components are allowed to run a compatible communication protocol (e.g., interoperable communication protocol) but are not required to operate an interoperable software version.

Abstract: Example implementations relate to preserving data availability in a constrained deployment of an HA system (e.g., an HA storage system) in the presence of pending faults. According to an example, a first arbiter, acting as a witness to facilitate maintaining quorum for the HA system, and a first node are provided within a first failure domain; and a second arbiter, serving as a backup arbiter, and a second node are provided within a second failure domain. Responsive to receipt of an indication of a pending fault impacting the first failure domain by a member of the current configuration of the HA system, establishment of a new configuration, excluding the first arbiter and including the second arbiter, is initiated. Responsive to a majority of the current configuration installing the new configuration, the second arbiter is enabled to serve as the active arbiter by transferring state information to the second arbiter.

Abstract: A source system generates snapshots of collected data. The snapshots have respective associated time references. Responsive to a request from a target system for data collected over a time interval, the source system generates a subset of the data collected by determining a start snapshot and an end snapshot. The start snapshot and the end snapshot are determined as a pair of snapshots that have respective associated time references that are most closely spaced and are inclusive of the time interval. The source system determines a difference in the data included in the end snapshot and the start snapshot and provides the subset of the data as the difference in the data included in the end snapshot and the start snapshot.

Abstract: Cluster groups define a relationship between clusters in an HCI system. New cluster groups may be created, and a cluster may be added or removed from an existing cluster group. A method and system are disclosed to support a dynamically scaled hyperconverged system with non-overlapping and overlapping cluster groups. A dynamically scalable hyperconverged system may allow for piece-wise upgrades while supporting inter-operable and non-interoperable components having a secure intercommunication capability. A system is disclosed for scaling a single managed hyperconverged infrastructure (HCI) where all components are allowed to run a compatible communication protocol (e.g., interoperable communication protocol) but are not required to operate an interoperable software version.

Abstract: A system and method generates a message integrity check. The message integrity check value is computed by hashing one or more block checksums from procedure specific parameters of an RPC and then encrypting the resulting hash value. The computed message integrity check is appended to the RPC to thereby provide a level of security approaching or equal to the level of Integrity defined by the RPCSEC_GSS protocol specification.

Abstract: A file system layout apportions an underlying physical volume into one or more virtual volumes (vvols) of a storage system. The underlying physical volume is an aggregate comprising one or more groups of disks, such as RAID groups, of the storage system. The aggregate has its own physical volume block number (pvbn) space and maintains metadata, such as block allocation structures, within that pvbn space. Each vvol has its own virtual volume block number (vvbn) space and maintains metadata, such as block allocation structures, within that vvbn space. Notably, the block allocation structures of a vvol are sized to the vvol, and not to the underlying aggregate, to thereby allow operations that manage data served by the storage system (e.g., snapshot operations) to efficiently work over the vvols. The file system layout extends the file system layout of a conventional write anywhere file layout system implementation, yet maintains performance properties of the conventional implementation.

Abstract: An on-disk structure of a file system has the capability to generate snapshots and provide fast sequential read access to data containers, such as files. The on-disk structure arranges sequential portions of files on disk within regions, wherein each region comprises a predetermined amount of disk space represented by blocks and wherein the data of the files stored within each region may or may not be stored sequentially within the region. In addition, the on-disk structure accommodates a plurality of types of regions, including (i) active regions that contain active file system data for large files, (ii) snapshot regions that contain “copy out” snapshot data for the large files and (iii) metadata regions that contain metadata, as well as directories and small files.

Abstract: A method for operating a computer data storage system is described. A plurality of requests are received from a client, each request of the plurality of requests having assigned a unique sequence number, each request being an input/output request to a data storage device. The plurality of requests is divided into a plurality of subsets of requests. A unique batch number is assigned to each subset of requests so that each subset of requests is assigned a unique batch number. A first subset of requests having a first batch number is executed in arbitrary order with respect to the sequence number of each request. A second subset of requests is executed in response to a second batch number after execution of all of the first subset of requests has completed.

Abstract: An on-disk structure of a file system has the capability to efficiently manage and organize data containers, such as snapshots, stored on a storage system. A multi-bit, monotonically increasing, snapshot identifier (“snapid”) is provided that represents a snapshot and that increases every time a snapshot is generated for a volume of the storage system. The snapid facilitates organization of snapshot metadata within, e.g., a data structure used to organize metadata associated with snapshot data. In the illustrative embodiment, the data structure is a balanced tree structure configured to index the copy-out snapshot data blocks. The snapid is also used to determine which blocks belong to which snapshots. To that end, every block that is used in a snapshot has an associated “valid-to” snapid denoting the newest snapshot for which the block is valid. The oldest snapshot for which the block is valid is one greater than the valid-to field of the next older block at the same file block number.

Abstract: A method for operating a computer data storage system is described. A plurality of requests are received from a client, each request of the plurality of requests having assigned a unique sequence number, each request being an input/output request to a data storage device. The plurality of requests is divided into a plurality of subsets of requests. A unique batch number is assigned to each subset of requests so that each subset of requests is assigned a unique batch number. A first subset of requests having a first batch number is executed in arbitrary order with respect to the sequence number of each request. A second subset of requests is executed in response to a second batch number after execution of all of the first subset of requests has completed.

Abstract: A system and method generates a message integrity check. The message integrity check value is computed by hashing one or more block checksums from procedure specific parameters of an RPC and then encrypting the resulting hash value. The computed message integrity check is appended to the RPC to thereby provide a level of security approaching or equal to the level of Integrity defined by the RPCSEC_GSS protocol specification.

Abstract: A file system layout apportions an underlying physical volume into one or more virtual volumes (vvols) of a storage system. The underlying physical volume is an aggregate comprising one or more groups of disks, such as RAID groups, of the storage system. The aggregate has its own physical volume block number (pvbn) space and maintains metadata, such as block allocation structures, within that pvbn space. Each vvol has its own virtual volume block number (vvbn) space and maintains metadata, such as block allocation structures, within that vvbn space. Notably, the block allocation structures of a vvol are sized to the vvol, and not to the underlying aggregate, to thereby allow operations that manage data served by the storage system (e.g., snapshot operations) to efficiently work over the vvols. The file system layout extends the file system layout of a conventional write anywhere file layout system implementation, yet maintains performance properties of the conventional implementation.

Abstract: A system and method generates a message integrity check. The message integrity check value is computed by hashing one or more block checksums from procedure specific parameters of an RPC and then encrypting the resulting hash value. The one or more block checksums may be quickly computed using conventional data checksumming procedures for the data contained within the RPC. As such, the computations to hash the block checksums is minimal. The computed message integrity check is appended to the RPC to thereby provide a level of security approaching or equal to the level of Integrity defined by the RPCSEC_GSS protocol specification.

Abstract: An on-disk structure of a file system has the capability to generate snapshots and provide fast sequential read access to data containers, such as files. The on-disk structure arranges sequential portions of files on disk within regions, wherein each region comprises a predetermined amount of disk space represented by blocks and wherein the data of the files stored within each region may or may not be stored sequentially within the region. In addition, the on-disk structure accommodates a plurality of types of regions, including (i) active regions that contain active file system data for large files, (ii) snapshot regions that contain “copy out” snapshot data for the large files and (iii) metadata regions that contain metadata, as well as directories and small files.

Abstract: A file system layout apportions an underlying physical volume into one or more virtual volumes (vvols) of a storage system. The underlying physical volume is an aggregate comprising one or more groups of disks, such as RAID groups, of the storage system. The aggregate has its own physical volume block number (pvbn) space and maintains metadata, such as block allocation structures, within that pvbn space. Each vvol has its own virtual volume block number (vvbn) space and maintains metadata, such as block allocation structures, within that vvbn space. Notably, the block allocation structures of a vvol are sized to the vvol, and not to the underlying aggregate, to thereby allow operations that manage data served by the storage system (e.g., snapshot operations) to efficiently work over the vvols.

Abstract: An on-disk structure of a file system has the capability to maintain snapshot and file system metadata on a storage system. The on-disk structure arranges file system data sequentially on disk within regions, wherein each region comprises a predetermined amount of disk space represented by blocks. The snapshot and file system metadata is maintained within level 1 (L1) indirect blocks of the on-disk structure. Each L1 indirect block describes (i.e., represents) a corresponding region of the on-disk structure of the file system; in the case of an active region, e.g., an L1 indirect block represents an active file data portion of a large file. The L1 indirect block that references an active region also performs file block number (fbn) to disk block number (dbn) mapping for the region.

Abstract: A triple parity (TP) technique reduces overhead of computing diagonal and anti-diagonal parity for a storage array adapted to enable efficient recovery from the concurrent failure of three storage devices in the array. The diagonal parity is computed along diagonal parity sets that collectively span all data disks and a row parity disk of the array. The parity for all of the diagonal parity sets except one is stored on the diagonal parity disk. Similarly, the anti-diagonal parity is computed along anti-diagonal parity sets that collectively span all data disks and a row parity disk of the array. The parity for all of the anti-diagonal parity sets except one is stored on the anti-diagonal parity disk. The TP technique provides a uniform stripe depth and an optimal amount of parity information.

Abstract: An on-disk structure of a file system has the capability to generate snapshots and provide fast sequential read access to data containers, such as files. The on-disk structure arranges sequential portions of files on disk within regions, wherein each region comprises a predetermined amount of disk space represented by blocks and wherein the data of the files stored within each region may or may not be stored sequentially within the region. In addition, the on-disk structure accommodates a plurality of types of regions, including (i) active regions that contain active file system data for large files, (ii) snapshot regions that contain “copy out” snapshot data for the large files and (iii) metadata regions that contain metadata, as well as directories and small files.