公开(公告)号：US20170192710A1

公开(公告)日：2017-07-06

申请号：US14988435

申请日：2016-01-05

Applicant: NetApp, Inc.

Inventor： Anshul Pundir ,  Ling Zheng ,  David Brittain Bolen

IPC: G06F3/06

CPC classification number: G06F3/0644 ,  G06F3/0608 ,  G06F3/067

Abstract: A technique enables recovery of storage space trapped in an extent store due to overlapping write requests associated with metadata managed by a volume layer of a storage input/output stack executing on one or more nodes of a cluster. The metadata is organized as a multi-level dense tree metadata structure, wherein each level of the dense tree includes volume metadata entries for storing the metadata. When a level of the dense tree is full, the volume metadata entries of the level are merged with a next lower level of the dense tree in accordance with a dense tree merge operation. The technique may be invoked during the merge operation to process the volume metadata entries associated with the overlapping write requests at each level of the dense tree involved in the merge operation. Processing of the overlapping write requests during the merge operation may manifest as partial overwrites of one or more existing extents which, in turn, may result in logical storage space being trapped in the extent store. The technique may perform read-modify-write (RMW) operations on the partially overwritten extents to recapture that trapped space. The storage space trapped by the partially overwritten extents may be recovered by reading and re-writing one or more valid portions of each extent with storage space lockup through the use of “out-of-band”, i.e., independent of the merge, processing of the RMW operations.

公开(公告)号：US10394660B2

公开(公告)日：2019-08-27

申请号：US14815064

申请日：2015-07-31

Applicant: NetApp, Inc.

Inventor： David Brittain Bolen ,  Suhas Prakash ,  Anshul Pundir ,  Ling Zheng

IPC: G06F3/06 ,  G06F11/14

Abstract: A snap restore technique efficiently restores snapshots of storage containers served by a storage input/output (I/O) stack executing on one or more nodes of a cluster. A Small Computer Systems Interface administration layer interacts with a volume layer of the storage I/O stack to manage and implement a snap restore procedure to restore one or more snapshots of a storage container. The storage container may be a logical unit (LUN) embodied as parent volume (active volume) and the snapshot may be represented as an independent volume embodied as read-only copy of the active volume. The snap restore procedure may be configured to allow restoration to a single snapshot of a LUN or restoration of a plurality of LUNs organized as a consistency group from a group of snapshots. Restoration of the LUN from a snapshot involves (i) creation of another independent volume embodied as a read-write copy (clone) of the snapshot, (ii) replacement of the (old) active volume with the clone, (iii) deletion of the old active volume, and (iv) mapping of the LUN to the clone (i.e., a new active volume).

公开(公告)号：US20170031774A1

公开(公告)日：2017-02-02

申请号：US14815064

申请日：2015-07-31

Applicant: NetApp, Inc.

Inventor： David Brittain Bolen ,  Suhas Prakash ,  Anshul Pundir ,  Ling Zheng

IPC: G06F11/14 ,  G06F3/06

CPC classification number: G06F11/1458 ,  G06F3/0619 ,  G06F3/065 ,  G06F3/067 ,  G06F11/00 ,  G06F2201/84

Abstract: A snap restore technique efficiently restores snapshots of storage containers served by a storage input/output (I/O) stack executing on one or more nodes of a cluster. A Small Computer Systems Interface administration layer interacts with a volume layer of the storage I/O stack to manage and implement a snap restore procedure to restore one or more snapshots of a storage container. The storage container may be a logical unit (LUN) embodied as parent volume (active volume) and the snapshot may be represented as an independent volume embodied as read-only copy of the active volume. The snap restore procedure may be configured to allow restoration to a single snapshot of a LUN or restoration of a plurality of LUNs organized as a consistency group from a group of snapshots. Restoration of the LUN from a snapshot involves (i) creation of another independent volume embodied as a read-write copy (clone) of the snapshot, (ii) replacement of the (old) active volume with the clone, (iii) deletion of the old active volume, and (iv) mapping of the LUN to the clone (i.e., a new active volume).

Abstract translation: 快速恢复技术有效地恢复由集群的一个或多个节点上执行的存储输入/输出（I / O）堆栈服务的存储容器的快照。 小型计算机系统接口管理层与存储I / O堆栈的卷层交互以管理和实现快照恢复过程以恢复存储容器的一个或多个快照。 存储容器可以是体现为父卷（活动卷）的逻辑单元（LUN），并且快照可以被表示为体现为活动卷的只读副本的独立卷。 快照恢复过程可以被配置为允许恢复LUN的单个快照或从一组快照组织为一致性组的多个LUN的恢复。 从快照恢复LUN涉及（i）创建体现为快照的读写副本（克隆）的另一独立卷，（ii）使用克隆替换（旧）活动卷，（iii）删除 旧的活动卷，以及（iv）将LUN映射到克隆（即，新的活动卷）。

公开(公告)号：US09830103B2

公开(公告)日：2017-11-28

申请号：US14988435

申请日：2016-01-05

Applicant: NetApp, Inc.

Inventor： Anshul Pundir ,  Ling Zheng ,  David Brittain Bolen

IPC: G06F3/06

CPC classification number: G06F3/0644 ,  G06F3/0608 ,  G06F3/067

Abstract: A technique enables recovery of storage space trapped in an extent store from overlapping write requests associated with metadata describing volume logical storage addresses for data in the extent store. The metadata is organized as metadata entries in a multi-level dense tree metadata structure. When a level of the dense tree is full, the metadata entries of the level are merged with a next lower level of the dense tree in accordance with a dense tree merge operation. The technique may be invoked during the merge operation to process the metadata entries associated with the overlapping write requests involved in the merge operation. Processing of the overlapping write requests during the merge operation may partially overwrite extents which, in turn, may result in logical storage space being trapped in the extent store. The technique may perform read-modify-write (RMW) operations on the partially overwritten extents to recapture that trapped space.