Snapshot image for the application state of unshareable and shareable data

• US 6,917,963 B1
• Filed: 10/05/2000
• Issued: 07/12/2005
• Est. Priority Date: 10/05/1999
• Status: Expired due to Term

• Current Assignee: Veritas Technologies, LLC (Whitehouse Group Ltd.)
• Original Assignee: Veritas Operating Corporation (Gen Digital Inc.)
• Inventors: Bharadhwaj, Rajeev, Hipp, Burton A.
• Primary Examiner(s): Vaughn, Jr., William C.
• Application Number:
  US09/684,373
• Time in Patent Office: 1,741 Days
• Field of Search: 719/328, 719315-319, 719/312, 719/313, 714 37- 40, 714 15- 21, 714/6, 707200-203, 707/9, 707/10, 713163-165, 709/204, 709/205, 709/201, 709/203, 709/225, 709/227, 709/229, 709/245, 709/215, 709/216, 345/330, 715/516, 711/6, 711/100, 711/155, 711/163, 711/200
• US Class Current: 709/204
• CPC Class Codes: G06F 2209/482 Application
• CPC Class Codes: G06F 9/44505 Configuring for program initiating, e.g. using registry, configuration files
• CPC Class Codes: G06F 9/4856 resumption being on a different machine, e.g. task migration, virtual machine migration G06F9/5088 takes precedence

Abstract

A system, methods, and computer program products are disclosed for creating virtual application templates for the purpose of propagating a single application snapshot into multiple, distinct images. Snapshot virtual templates allow multiple application instances to use the same fixed resource identifier by making the resource identifier virtual, privatizing it, and dynamically mapping it to a unique system resource identifier. When a snapshot is cloned from a virtual template, the common or shared data is used exactly as is, whereas the non-sharable data is either copied-on-write, multiplexed, virtualized, or customized-on-duplication. The present invention notes access to modified resources, fixed system IDs/keys and unique process-related identifies and automatically inserts a level of abstraction between these resources and the application. The resources contained in a snapshot virtual template can be dynamically redirected at restore time. Access to memory and storage is managed in a copy-on-write fashion. System resource handles are managed in a virtualize-on-allocate fashion or by a multiplex-on-access mechanism. Process-unique resources are managed in a redirect-on-duplicate fashion. Rules may be defined through an application configurator that allows some degree of control over the creation of non-sharable data. The snapshot virtual template is constructed by dividing the snapshot image into sharable and non-sharable data. Knowledge of which system resources can be shared is encoded in the application snapshot/restore framework.

Claims

1. A method comprising:

creating a snapshot image from a first instance of a software application running on a first computer, wherein the snapshot image comprises application state associated with the software application;

dividing the application state into shareable data and non-shareable data, wherein shareable data comprises read-only data or data that is functionally isolated from other applications, and wherein non-shareable data comprises data that is modified and is globally visible to other applications; and

restoring a second instance of the software application on a second computer different from the first computer, wherein the second instance and the first instance are distinct instances of the software application, and wherein the restoring comprises;

providing the shareable data to the second instance, and

controlling access by the second instance to the non-shareable data, wherein

controlling access comprises dynamically redirecting the non-shareable, and

wherein at least a first portion of the non-shareable data is virtualized.

2. The method of claim 1, wherein a second portion of the non-shareable data is copied on a write operation.

3. The method of claim 1, wherein a second portion of the non-shareable data is multiplexed.

4. The method of claim 1, wherein the second instance is altered to provide customization of the software application.

5. The method of claim 1, wherein references to the non-sharable data are saved in original form.

6. A memory medium storing a plurality of instructions comprising instructions which, when executed:

create snapshot image from a first instance of a software application running on a first computer, wherein the snapshot image comprises application state associated with the software application;

divide the application state into shareable data and non-shareable data, wherein shareable data comprises read-only data or data that is functionally isolated from other applications, and wherein non-shareable data comprises data that is modified and is globally visible to other applications; and

restore a second instance of the software application on a second computer different from the first computer, wherein the second instance and the first instance are distinct of the software application, and wherein the restore comprises;

providing the shareable data to the second instance, and

controlling access by the second instance to the non-shareable data,

wherein controlling access comprises dynamically redirecting the non-shareable data, and wherein at least a first portion of the non-shareable data is virtualized.

7. The memory medium of claim 6, wherein a second portion of the non-shareable data is copied on a write operation.

8. The memory medium of claim 6, wherein a second portion of the non-shareable data is multiplexed.

9. The memory medium of claim 6, wherein the second instance is altered to provide customization of the software application.

10. The memory medium of claim 6, wherein references to the non-sharable data are saved in original form.

11. A system operable to:

create a snapshot image from a first instance of a software application running on a first computer, wherein the snapshot image comprises application state associated with the software application;

divide the application state into shareable data and non-shareable data, wherein shareable data comprises read-only data or data that is functionally isolated from other applications, and wherein non-shareable data comprises data that is modified and is globally visible to other applications; and

restore a second instance of the software application on a second computer different from the first computer, wherein the second instance and the first instance are distinct of the software application, and wherein the restore comprises;

providing the shareable data to the second instance, and

controlling access by the second instance to the non-shareable data,

wherein controlling access comprises dynamically redirecting the non-shareable data, and wherein at least a first portion of the non-shareable data is virtualized.

12. The system of claim 11, wherein a second portion of the non-shareable data is copied on a write operation.

13. The system of claim 11, wherein a second portion of the non-shareable data is multiplexed.

14. The system of claim 11, wherein the second instance is altered to provide customization of the software application.

15. The system of claim 11, wherein references to the non-sharable data are saved in original form.

16. The system of claim 11, wherein the system comprises:

a first software module that processes transactions between an operating system and the software application, and tracks requests for system resources or changes to the application state in anticipation of creation of a snapshot image;

a storage format for organizing the snapshot image into shareable and non-sharable data, the storage format manipulated by the first software module; and

a second module that fields requests for non-shareable data, duplicates the non-sharable data and provides the duplicated non-sharable data to the instance.