Near continuous data protection without using snapshots
AssigneeEMC IP Holding Company LLC
InventorsJehuda Shemer, Ravi Vijayakumar Chitloor
Life of this patent
Estimating the term…
Abstract
One example method includes performing delta operations to protect data. A delta queue is provided that allows a replica volume to be rolled forwards and backwards in time. When rolling the replica volume forward, an undo delta is created such that the replica volume can be moved backwards after being moved forward. When rolling the replica volume backwards, a forward delta is created such that the replica volume can be moved forwards after being moved backwards.
Claims20
A method, comprising:
- selecting a delta from a delta queue that includes deltas including forward deltas and undo deltas, each of the deltas including extents and metadata associated with a source volume, wherein the extents include changes since a previous delta operation;
- moving a replica volume at a first point in time to a second point in time associated with the selected delta, wherein the second point in time is earlier than the first point in time, wherein moving the replica volume includes:
- creating a forward delta associated with the first point in time such that the replica volume can be rolled forward to the first point in time using the forward delta after moving the replica volume to the second point in time;
- and
- moving the replica volume to the second point in time by applying extents identified from metadata of the selected delta to the replica volume.
A method, comprising:
- selecting a delta from a delta queue that includes deltas including forward deltas and undo deltas, each delta including extents and metadata associated with a source volume, wherein the extents include changes since a previous delta operation;
- moving a replica volume at a first point in time to a second point in time associated with the selected delta, wherein the second point in time is later than the first point in time, wherein moving the replica volume includes:
- creating an undo delta associated with the first point in time such that the replica volume can be rolled back to the first point in time using the undo delta after moving the replica volume to the second point in time;
- and
- moving the replica volume to the second point in time by applying extents identified from the metadata of the selected delta to the replica volume.
A non-transitory storage medium having stored therein instructions that are executable by one or more hardware processors to perform operations comprising:
- selecting a delta from a delta queue that includes deltas including forward deltas and undo deltas, each delta including extents and metadata associated with a source volume, wherein the extents include changes since a previous delta operation;
- moving a replica volume at a first point in time to a second point in time associated with the selected delta;
- when the second point in time is earlier than the first point in time:
- creating a forward delta such that the replica volume can be rolled forward to the first point in time using the forward delta after moving the replica volume to the second point in time;
- and
- moving the replica volume to the second point in time by applying extents identified from metadata of the selected delta to the replica volume;
- and
- when the second point in time is later than the first point in time:
- creating an undo delta such that the replica volume can be rolled back to the first point in time using the undo delta after moving the replica volume to the second point in time;
- and
- moving the replica volume to the second point in time by applying extents identified from the metadata of the selected delta to the replica volume.
Dependencies are inferred from the claim text.