Granted Patent B2

US 8,856,471 · App. 13/705,415 · Granted Oct 7, 2014

Inventor: Josef Ezra (Even Yehuda, IL)

Assignee: Infinidat Ltd.

G06F3/065G06F3/0673G06F3/0614

Abstract

Claims (57)

1. A method for providing a warranted snapshot, the method comprises:

receiving a request to create a first warranted snapshot of a first logical volume at a first point in time;

creating the first warranted snapshot if the first warranted snapshot is non-writable and if (a) an amount of physical storage actually devoted by a storage system to the first logical volume at the first point of time does not exceed (b) a size of a free physical storage space that is available for storing any future data delta associated with the first warranted snapshot;

wherein the creating of the first warranted snapshot comprises allocating a first virtual portion of a physical storage space that comprises the free physical storage space for storing any future data delta associated with the first warranted snapshot; wherein a size of the first virtual portion equals the amount of physical storage actually devoted to the first logical volume at the first point of time.

2. The method according to claim 1 , comprising failing to create the first warranted snapshot if the first warranted snapshot is non-writable and if (a) the amount of physical storage actually devoted by the storage system to the first logical volume at the first point of time exceeds (b) the size of the free physical storage space that is available for storing any future data delta associated with the first warranted snapshot.

3. The method according to claim 2 , wherein the failing to create the first warranted snapshot is followed by creating a non-warranted snapshot of the first logical volume at the first point in time.

4. The method according to claim 1 , further comprising receiving at least one future data delta associated with the first warranted snapshot and storing each of the at least one future data deltas within the physical storage space.

5. The method according to claim 1 , further comprising monitoring an amount of physical storage space actually devoted to any data delta associated with the first warranted snapshot.

6. The method according to claim 1 , wherein the allocating of the first virtual portion of the physical storage space does not involve actually allocating an actual portion of the physical storage space of a size that equals the amount of physical storage actually devoted to the first logical volume at the first point of time.

7. The method according to claim 1 , wherein the creating of the first warranted snapshot comprises actually allocating an actual portion of the physical storage space of a size that equals the amount of physical storage actually devoted to the first logical volume at the first point of time.

8. The method according to claim 1 , wherein the physical storage space is associated only with snapshots of the first volume.

9. The method according to claim 1 , wherein the physical storage space is associated with a consistency group that comprises the first logical volume and at least one other logical volume.

10. The method according to claim 1 , wherein the first logical volume is a thin logical volume and wherein the method comprises monitoring actual allocation of physical storage space fractions to portions of the first logical volume and determining, in response to the monitoring, the amount of physical storage actually devoted by the storage system to the first logical volume at the first point of time.

11. The method according to claim 1 , wherein the first logical volume is a thick logical volume and wherein the method comprises monitoring a utilization of physical storage space fractions of a physical storage space allocated to the first logical volume and determining, in response to the monitoring, the amount of physical storage actually devoted by the storage system to the first logical volume at the first point of time.

12. The method according to claim 11 , comprising updating a size of the first virtual portion to the amount of physical storage space actually devoted to any data delta associated with the first warranted snapshot.

13. The method according to claim 1 , comprising:

receiving a request to create a second warranted snapshot of the first logical volume at a second point in time;

wherein the first warranted snapshot is a last snapshot of the first logical volume that was created before the second point in time;

calculating a size of a free physical storage space that is available for storing any future data delta associated with the second warranted snapshot by taking into account an amount of physical storage space actually devoted to any data delta associated with the first warranted snapshot;

creating the second warranted snapshot if the second warranted snapshot is non-writable and if (a) an amount of physical storage actually devoted by the storage system to the first logical volume at the second point of time does not exceed (b) a size of a free physical storage space that is available for storing any future data delta associated with the second warranted snapshot;

wherein the creating of the second warranted snapshot comprises allocating a second virtual portion of the physical storage space that comprises the free physical storage space for storing any future data delta associated with the second warranted snapshot; wherein a size of the second virtual portion equals the amount of physical storage actually devoted to the first logical volume at the second point of time.

14. The method according to claim 1 , comprising

receiving a request to create a certain warranted snapshot that reflects the first logical volume at a certain point in time;

creating the certain warranted snapshot if the certain warranted snapshot is writable and if (a) a size of the first logical volume at the certain point of time does not exceed (b) a size of a free physical storage space that is available for storing any future data delta associated with the certain warranted snapshot;

wherein the creating of the certain warranted snapshot comprises allocating a certain virtual portion of the physical storage space that comprises the free physical storage space for storing any future data delta associated with the certain warranted snapshot; wherein a size of the certain virtual portion equals the size of the first logical volume at the certain point of time.

15. The method according to claim 1 , comprising:

receiving a request to create, at a point in time that follows the first point in time, a writable warranted snapshot that reflects the first warranted snapshot;

creating the writable warranted snapshot if the (a) a size of the first volume at the point in time does not exceed (b) a size of a free physical storage space that is available for storing any future data deltas associated with the writable warranted snapshot;

wherein the creating of the writable warranted snapshot comprises allocating a virtual portion of the physical storage space for storing and any future data deltas associated with the writable warranted snapshot; wherein a size of the virtual portion equals the size of the first logical volume at the point of time.

16. A method for providing a warranted snapshot, the method comprises:

receiving a request to create a first warranted snapshot of a first logical volume at a first point in time;

determining whether a type of the first warranted snapshot is writable or non-writable;

creating a first non-writable warranted snapshot if it is determined that the type of the first warranted snapshot is non-writable and if (a) an amount of physical storage actually devoted by a storage system to the first logical volume at the first point of time does not exceed (b) a size of a free physical storage space that is available for storing any future data delta associated with the first non-writable warranted snapshot;

creating a first writable warranted snapshot if it is determined that the type of the first warranted snapshot is writable and if (a) a size of the first logical volume at the first point of time does not exceed (b) a size of the free physical storage space that is available for storing any future data delta associated with the first writable warranted snapshot;

wherein the creating of the first non-writable warranted snapshot comprises allocating a first virtual portion having a size that equals the amount of physical storage actually devoted to the first logical volume at the first point of time, the first virtual portion is associated with the physical storage space and is assigned for storing any future data delta associated with the first non-writable warranted snapshot;

wherein the creating of the first writable warranted snapshot comprises allocating a first virtual portion having a size that equals the size of the first logical volume at the first point of time, the first virtual portion is associated with the physical storage space and is assigned for storing any future data delta associated with the first writable warranted snapshot.

17. A non-transitory computer readable medium that stores instructions to be executed by a computerized system for:

receiving a request to create a first warranted snapshot of a first logical volume at a first point in time;

creating the first warranted snapshot if the first warranted snapshot is non-writable and if (a) an amount of physical storage actually devoted by a storage system to the first logical volume at the first point of time does not exceed (b) a size of a free physical storage space that is available for storing any future data delta associated with the first warranted snapshot;

wherein the creating of the first warranted snapshot comprises allocating a first virtual portion of a physical storage space that comprises the free physical storage space for storing any future data delta associated with the first warranted snapshot; wherein a size of the first virtual portion equals the amount of physical storage actually devoted to the first logical volume at the first point of time.

18. A non-transitory computer readable medium that stores instructions to be executed by a computerized system for:

receiving a request to create a first warranted snapshot of a first logical volume at a first point in time;

determining whether a type of the first warranted snapshot is writable or non-writable;

creating a first non-writable warranted snapshot if it is determined that the type of the first warranted snapshot is non-writable and if (a) an amount of physical storage actually devoted by a storage system to the first logical volume at the first point of time does not exceed (b) a size of a free physical storage space that is available for storing any future data delta associated with the first non-writable warranted snapshot;

creating a first writable warranted snapshot if it is determined that the type of the first warranted snapshot is writable and if (a) a size of the first logical volume at the first point of time does not exceed (b) a size of the free physical storage space that is available for storing any future data delta associated with the first writable warranted snapshot;

wherein the creating of the first non-writable warranted snapshot comprises allocating a first virtual portion having a size that equals the amount of physical storage actually devoted to the first logical volume at the first point of time, the first virtual portion is associated with the physical storage space and is assigned for storing any future data delta associated with the first non-writable warranted snapshot;

wherein the creating of the first writable warranted snapshot comprises allocating a first virtual portion having a size that equals the size of the first logical volume at the first point of time, the first virtual portion is associated with the physical storage space and is assigned for storing any future data delta associated with the first writable warranted snapshot.

19. A system comprising:

a storage control unit arranged to receive a request to create a first warranted snapshot of a first logical volume at a first point in time;

a warranted snapshot module arranged to create the first warranted snapshot if the first warranted snapshot is non-writable and if (a) an amount of physical storage actually devoted by a storage system to the first logical volume at the first point of time does not exceed (b) a size of a free physical storage space that is available for storing any future data delta associated with the first warranted snapshot;

wherein a creation of the first warranted snapshot comprises allocating a first virtual portion of a physical storage space that comprises the free physical storage space for storing any future data delta associated with the first warranted snapshot; wherein a size of the first virtual portion equals the amount of physical storage actually devoted to the first logical volume at the first point of time.

20. A system comprising:

a storage control unit arranged to receive a request to create a first warranted snapshot of a first logical volume at a first point in time and to determine whether a type of the first warranted snapshot is writable or non-writable;

a warranted snapshot module arranged to create a first non-writable warranted snapshot if it is determined that the type of the first warranted snapshot is non-writable and if (a) an amount of physical storage actually devoted by a storage system to the first logical volume at the first point of time does not exceed (b) a size of a free physical storage space that is available for storing any future data delta associated with the first non-writable warranted snapshot;

a non-warranted snapshot module arranged to create a first writable warranted snapshot if it is determined that the type of the first warranted snapshot is writable and if (a) a size of the first logical volume at the first point of time does not exceed (b) a size of the free physical storage space that is available for storing any future data delta associated with the first writable warranted snapshot;

wherein a creation of the first non-writable warranted snapshot comprises allocating a first virtual portion having a size that equals the amount of physical storage actually devoted to the first logical volume at the first point of time, the first virtual portion is associated with the physical storage space and is assigned for storing any future data delta associated with the first non-writable warranted snapshot;

wherein a creation of the first writable warranted snapshot comprises allocating a first virtual portion having a size that equals the size of the first logical volume at the first point of time, the first virtual portion is associated with the physical storage space and is assigned for storing any future data delta associated with the first writable warranted snapshot.

Assignments (10)

Continuity (1)