Conditional storage of multiple information items

Patent metadata

Field	Value
Publication number	US-9208192-B2
Application number	US-39833909-A
Country	US
Kind code	B2
Filing date	Mar 5, 2009
Priority date	Mar 5, 2009
Publication date	Dec 8, 2015
Grant date	Dec 8, 2015

Abstract

A method for consistent version of multiple information items is provided. The method includes receiving a conditional request to copy a version of multiple information items at a condition fulfillment point of time that is associated with a fulfillment of a condition of the conditional request. Then determining that the condition is fulfilled, and participating in generating a condition fulfillment point in time version of the multiple information items.

First claim

What is claimed is:

1. A method for generating a conditionally consistent version of multiple information items, the method comprising:
receiving, using a hardware processor of a storage controller, a conditional request to copy a version of multiple information items at a condition fulfillment point of time that is determined upon fulfillment of two or more conditions, wherein the conditional request comprises the two or more conditions and indication of memory spaces that store the multiple information items;
setting a bit-map after receiving the conditional request that includes a representation of all of the multiple information items;
monitoring read requests and/or write requests for the multiple information items after receiving the conditional request;
delaying generation of a point in time version of the multiple information items until fulfillment of the two or more conditions for relaxing timing constraints on generation of the point in time version of the multiple information items;
determining, using the hardware processor of the storage controller, that all of the two or more conditions are fulfilled;
determining the condition fulfillment point of time, wherein the condition fulfillment point in time is set at a time when the two or more conditions are fulfilled or after the two or more conditions are fulfilled;
updating the bit-map to reflect which of the multiple information items have been read since receiving the conditional request; and
participating in generating a condition fulfillment point in time version of the multiple information items at the condition fulfillment point of time.

2. The method according to claim 1 wherein one of the two or more conditions is a memory space coherency check condition, wherein the memory space coherency check condition is fulfilled upon receiving a request to write to a memory space that stores an information item, out of the multiple information items, that was read after receiving the conditional request.

3. The method according to claim 1 wherein one of the two or more conditions is an application coherency condition, wherein the application coherency condition is fulfilled upon receiving an application coherency indication.

4. The method according to claim 1 wherein one of the two or more conditions is a hazard condition, wherein the hazard condition is fulfilled upon detecting a potential hazard, the potential hazard being an update to a specific track and/or a write pattern that is not applicable on an updated track.

5. The method according to claim 1 further comprising:
monitoring availability of a memory entity selected from a source memory entity and a target memory entity;
wherein one of the conditions is a memory entity availability check condition, wherein the memory entity availability check condition is fulfilled upon the memory entity being capable of participating in generating the condition fulfillment point in time version of the multiple information items,
wherein being able to participate includes being available and not in use.

6. The method according to claim 1 further comprising:
wherein one of the conditions is a component load check condition, wherein the component load check condition is fulfilled in response to a load of a component being below a threshold, wherein the component participates in generation of the condition fulfillment point in time version of the multiple information items.

7. The method according to claim 1 wherein one of the two or more conditions is a cost check condition, wherein the cost check condition is fulfilled in response to a cost being below a threshold, the cost being associated with generation of the condition fulfillment point in time version of the multiple information items.

8. The method according to claim 1
wherein one of the two or more conditions is a performance parameter check condition, wherein the performance parameter check condition is fulfilled in response to a value of at least one performance parameter being at or beyond a predefined value, wherein the at least one performance parameter is detected by the storage controller or received by the storage controller; and
the method further comprising controlling, by the storage controller, the generation of the condition fulfillment point in time version of the multiple information items at the condition fulfillment point in time upon determining that all the conditions are fulfilled.

9. A storage system, comprising:
an interface configured to receive a conditional request to copy a version of multiple information items at a condition fulfillment point of time that is associated with fulfillment of at least one condition, wherein the at least one condition and indication of memory spaces that store the multiple information items is included in the conditional request; and
a storage controller coupled to a source memory storage entity, to the interface, and to a target memory storage entity,
wherein the storage controller is configured to participate in generating a condition fulfillment point in time version of the multiple information items at the condition fulfillment point in time which occurs upon or after the storage controller determining that the at least one condition is fulfilled,
wherein the storage controller is configured to set a bit-map after the conditional request is received, the bit-map including a representation of all of the multiple information items, and configured to update the bit-map to reflect which of the multiple information items have been read since the conditional request was received, and
wherein the at least one condition is selected from a group comprising:
receiving a request to write to a memory space that stores an information item, out of the multiple information items, that was read after receiving the conditional request;
receiving an application coherency indication;
detecting a potential hazard; and
determining that a memory storage entity selected from the source memory storage entity and the target memory storage entity is capable of participating in generating the condition fulfillment point in time version of the multiple information items,
wherein being able to participate includes being available and not in use.

10. The storage system according to claim 9 :
wherein the storage controller is further configured to monitor read requests and/or write requests for the multiple information items after receiving the conditional request,
wherein monitoring the read requests includes monitoring read requests that were directed to the target memory storage entity and re-directed to the source memory storage entity, and monitoring the write requests includes monitoring write requests directed to the source memory storage entity,
wherein the at least one condition further includes at least one of: a load on the target memory storage entity being below a first threshold, and a load on the source memory storage entity being below a second threshold, and
wherein participating in generating the condition fulfillment point in time version of the multiple information items includes copying from the source memory storage entity to the target memory storage entity only information items that were changed after a last snapshot was generated.

11. The storage system according to claim 9 wherein the group from which the at least one condition is selected further includes:
detecting that a load of a component is below a load threshold, wherein the component participates in generation of the condition fulfillment point in time version of the multiple information items; and/or
detecting that a cost is below a cost threshold, the cost being associated with generatio

Assignees

• Fienblit Shachar
• Goldberg Itzhack
• Malul Eli
• Sasson Amir
• IBM

Inventors

• Fienblit Shachar
• Goldberg Itzhack
• Malul Eli
• Sasson Amir

Classifications

• G06F16/2365 Primary

  Ensuring data consistency and integrity · CPC title

• G06F16/174

  Redundancy elimination performed by the file system (error detection or correction of the data by redundancy in operations G06F11/14) · CPC title

• G06F16/119

  Details of migration of file systems (migration mechanisms in storage systems G06F3/0647) · CPC title

• G06F17/3015

  Physics · mapped topic

• G06F17/30079

  Physics · mapped topic