公开(公告)号：US10929022B2

公开(公告)日：2021-02-23

申请号：US15137542

申请日：2016-04-25

Applicant: NetApp, Inc.

Inventor： Atul Goel ,  Ling Zheng ,  Prahlad Purohit

IPC: G06F3/06

Abstract: A technique efficiently determines accurate storage space savings reported to a host coupled to a reference-counted storage system that employs de-duplication and compression, wherein the storage space savings relate to snapshots and/or clones supported by the storage system. The snapshot/clone may be represented as an independent volume, and embodied as a respective read-only copy (snapshot) or read-write copy (clone) of a parent volume. Metadata is illustratively organized as one or more multi-level dense trees, wherein each level of each dense tree includes volume metadata entries for storing the metadata. The metadata is illustratively embodied as mappings from LBAs of a LUN to extent keys. Space adjustment counters, such as clone space adjustment (CSA) and diverged space adjustment (DSA) counters, may be employed when determining the storage space savings. The CSA counter is equal to the sum of mapped storage space across all levels of a dense tree. The DSA counter for the clone and for the snapshot equals the total mapped storage space in the level. The storage space savings may be determined by computing a value equal to the addition of the CSA counter to the total amount of data and metadata written to the LUN minus the DSA counters and, thereafter, dividing the value by the total amount of de-duplicated and compressed data for the LUN that is physically stored.

公开(公告)号：US09372767B2

公开(公告)日：2016-06-21

申请号：US14298344

申请日：2014-06-06

Applicant: NetApp, Inc.

Inventor： Tabriz Holtz ,  Neha Kapoor ,  Farshid Eslami Sarab ,  Afshin Salek Ardakani ,  Tara Faith Olson ,  Asif Imtiyaz Pathan ,  Prahlad Purohit

IPC: G06F11/00 ,  G06F11/20 ,  G06F11/16

CPC classification number: G06F11/2094 ,  G06F11/00 ,  G06F11/1666 ,  G06F2201/84

Abstract: A recovery consumer framework provides for execution of recovery actions by one or more recovery consumers to enable efficient recovery of information (e.g., data and metadata) in a storage system after a failure event (e.g., a power failure). The recovery consumer framework permits concurrent execution of recovery actions so as to reduce recovery time (i.e., duration) for the storage system. The recovery consumer framework may coordinate (e.g., notify) the recovery consumers to serialize execution of the recovery actions by those recovery consumers having a dependency while allowing concurrent execution between recovery consumers having no dependency relationship. Each recovery consumer may register with the framework to associate a dependency on one or more of the other recovery consumers. The dependency association may be represented as a directed graph where each vertex of the graph represents a recovery consumer and each directed edge of the graph represents a dependency. The framework may traverse (i.e., walk) the framework graph and for each vertex encountered, notify the associated recovery consumer to initiate its respective recovery actions.

Abstract translation: 恢复消费者框架提供了一个或多个恢复消费者执行恢复动作以使得能够在故障事件（例如电源故障）之后有效地恢复存储系统中的信息（例如，数据和元数据）。 恢复消费者框架允许并发执行恢复动作，以减少存储系统的恢复时间（即，持续时间）。 恢复消费者框架可以协调（例如，通知）恢复消费者以使具有依赖性的那些恢复消费者对恢复动作的执行进行序列化，同时允许没有依赖关系的恢复消费者之间的并发执行。 每个恢复消费者可以向框架注册以将依赖关系与一个或多个其他恢复消费者相关联。 依赖关联可以表示为有向图，其中图的每个顶点表示恢复消费者，并且图的每个有向边代表依赖性。 框架可以遍历（即，走）框架图，并且对于遇到的每个顶点，通知相关联的恢复消费者以启动其各自的恢复动作。

公开(公告)号：US20150355985A1

公开(公告)日：2015-12-10

申请号：US14298344

申请日：2014-06-06

Applicant: NetApp, Inc.

Inventor： Tabriz Holtz ,  Neha Kapoor ,  Farshid Eslami Sarab ,  Afshin Salek Ardakani ,  Tara Faith Olson ,  Asif Imtiyaz Pathan ,  Prahlad Purohit

IPC: G06F11/20 ,  G06F11/16

CPC classification number: G06F11/2094 ,  G06F11/00 ,  G06F11/1666 ,  G06F2201/84

Abstract: A recovery consumer framework provides for execution of recovery actions by one or more recovery consumers to enable efficient recovery of information (e.g., data and metadata) in a storage system after a failure event (e.g., a power failure). The recovery consumer framework permits concurrent execution of recovery actions so as to reduce recovery time (i.e., duration) for the storage system. The recovery consumer framework may coordinate (e.g., notify) the recovery consumers to serialize execution of the recovery actions by those recovery consumers having a dependency while allowing concurrent execution between recovery consumers having no dependency relationship. Each recovery consumer may register with the framework to associate a dependency on one or more of the other recovery consumers. The dependency association may be represented as a directed graph where each vertex of the graph represents a recovery consumer and each directed edge of the graph represents a dependency. The framework may traverse (i.e., walk) the framework graph and for each vertex encountered, notify the associated recovery consumer to initiate its respective recovery actions.

Abstract translation: 恢复消费者框架提供了一个或多个恢复消费者执行恢复动作以使得能够在故障事件（例如电源故障）之后有效地恢复存储系统中的信息（例如，数据和元数据）。 恢复消费者框架允许并发执行恢复动作，以减少存储系统的恢复时间（即，持续时间）。 恢复消费者框架可以协调（例如，通知）恢复消费者以使具有依赖性的那些恢复消费者对恢复动作的执行进行序列化，同时允许没有依赖关系的恢复消费者之间的并发执行。 每个恢复消费者可以向框架注册以将依赖关系与一个或多个其他恢复消费者相关联。 依赖关联可以表示为有向图，其中图的每个顶点表示恢复消费者，并且图的每个有向边代表依赖性。 框架可以遍历（即，走）框架图，并且对于遇到的每个顶点，通知相关联的恢复消费者以启动其各自的恢复动作。

公开(公告)号：US10191674B2

公开(公告)日：2019-01-29

申请号：US15130087

申请日：2016-04-15

Applicant: NetApp, Inc.

Inventor： Prahlad Purohit ,  Vidhyalakshmi Venkitakrishnan ,  Anthony J. Li

IPC: G06F3/06 ,  G06F11/30

Abstract: A consistency checker is configured to perform repairs to one or more multi-level dense tree metadata structures shared between volumes managed by a volume layer of a storage input/output (I/O) stack executing on one or more nodes of a cluster. The volumes include a parent volume and a snapshot and/or clone, wherein the snapshot/clone may be represented as an independent volume, and embodied as a respective read-only copy (snapshot) or read-write copy (clone) of the parent volume. Illustratively, the consistency checker verifies and/or fixes (i.e., repairs) on-disk structures of the volume layer, e.g., the shared dense tree, according to a distributed repair procedure that maintains consistency properties across all volumes in a volume family and avoid cyclic repairs made in the context of different volumes sharing the dense tree.

公开(公告)号：US20170315878A1

公开(公告)日：2017-11-02

申请号：US15143370

申请日：2016-04-29

Applicant: NetApp, Inc.

Inventor： Prahlad Purohit ,  Ling Zheng ,  Christopher Joseph Corsi

IPC: G06F11/14 ,  G06F17/30

CPC classification number: G06F11/1458 ,  G06F3/061 ,  G06F3/065 ,  G06F3/067 ,  G06F16/24573 ,  G06F16/27 ,  G06F2201/84

Abstract: A technique efficiently manages a snapshot and/or clone by a volume layer of a storage input/output (I/O) stack executing on one or more nodes of the cluster. According to the technique, an ownership attribute is included in metadata entries of a dense tree data structure for extents that eliminates otherwise needed reference count operations for the snapshots and reduces reference count operations for the clones. Illustratively, a copy of a parent dense tree level created by a copy-on-write (COW) operation is referred to as a “derived level”, whereas the existing level of the parent dense tree is referred to as a “source level”. The source level may be persistently linked to the derived level by keeping “level identifying key information” in a respective dense tree source level header. Moreover, two different types of dense tree derivations are defined: a derive relationship and a reverse-derive relationship.

公开(公告)号：US20170308305A1

公开(公告)日：2017-10-26

申请号：US15137542

申请日：2016-04-25

Applicant: NetApp, Inc.

Inventor： Atul Goel ,  Ling Zheng ,  Prahlad Purohit

IPC: G06F3/06

CPC classification number: G06F3/0608 ,  G06F3/0641 ,  G06F3/065 ,  G06F3/0665 ,  G06F3/067

Abstract: A technique efficiently determines accurate storage space savings reported to a host coupled to a reference-counted storage system that employs de-duplication and compression, wherein the storage space savings relate to snapshots and/or clones supported by the storage system. The snapshot/clone may be represented as an independent volume, and embodied as a respective read-only copy (snapshot) or read-write copy (clone) of a parent volume. Metadata is illustratively organized as one or more multi-level dense trees, wherein each level of each dense tree includes volume metadata entries for storing the metadata. The metadata is illustratively embodied as mappings from LBAs of a LUN to extent keys. Space adjustment counters, such as clone space adjustment (CSA) and diverged space adjustment (DSA) counters, may be employed when determining the storage space savings. The CSA counter is equal to the sum of mapped storage space across all levels of a dense tree. The DSA counter for the clone and for the snapshot equals the total mapped storage space in the level. The storage space savings may be determined by computing a value equal to the addition of the CSA counter to the total amount of data and metadata written to the LUN minus the DSA counters and, thereafter, dividing the value by the total amount of de-duplicated and compressed data for the LUN that is physically stored.

公开(公告)号：US20170300248A1

公开(公告)日：2017-10-19

申请号：US15130087

申请日：2016-04-15

Applicant: NetApp, Inc.

Inventor： Prahlad Purohit ,  Vidhyalakshmi Venkitakrishnan ,  Anthony J. Li

IPC: G06F3/06 ,  G06F17/30

CPC classification number: G06F3/0619 ,  G06F3/0623 ,  G06F3/0659 ,  G06F3/067 ,  G06F11/30

Abstract: A consistency checker is configured to perform repairs to one or more multi-level dense tree metadata structures shared between volumes managed by a volume layer of a storage input/output (I/O) stack executing on one or more nodes of a cluster. The volumes include a parent volume and a snapshot and/or clone, wherein the snapshot/clone may be represented as an independent volume, and embodied as a respective read-only copy (snapshot) or read-write copy (clone) of the parent volume. Illustratively, the consistency checker verifies and/or fixes (i.e., repairs) on-disk structures of the volume layer, e.g., the shared dense tree, according to a distributed repair procedure that maintains consistency properties across all volumes in a volume family and avoid cyclic repairs made in the context of different volumes sharing the dense tree.