Restarting a shared virtual resource

• US 7,587,723 B2
• Filed: 11/13/2003
• Issued: 09/08/2009
• Est. Priority Date: 11/13/2003
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: DeVilbiss, Colin Robert, Boutcher, David Charles
• Primary Examiner(s): An; Meng-Ai
• Assistant Examiner(s): Seye; Abdou K
• Application Number:
  US10/712,537
• Publication Number:
  US 20050108456A1
• Time in Patent Office: 2,126 Days
• Field of Search: 709/201, 719/325
• US Class Current: 719/325
• CPC Class Codes: G06F 2009/45575 Starting, stopping, suspending or resuming virtual machine instances
• CPC Class Codes: G06F 9/45558 Hypervisor-specific management and integration aspects

Abstract

An apparatus and method provide a protocol for communicating between an operating system that owns a shared resource and other operating systems that use the shared resource so that the operating systems that use the shared resource will not crash if the operating system that owns the shared resource is restarted. Messages are defined that allow handshaking between operating systems so that operating systems that share a resource will realize the resource will be unavailable for some period of time, and that allow resuming the sharing of the resource once the operating system that owns the shared resource is restarted.

Claims

1. A computer system comprising:

at least one processor;

a memory coupled to the at least one processor;

a first operating system residing in the memory, the first operating system owning a shared resource;

a second operating system residing in the memory, the second operating system using the shared resource;

the first operating system comprising a pause/resume mechanism that sends a pause message to the second operating system when the first operating system needs to be restarted, that receives a pause complete message from the second operating system to indicate the second operating system has completed pending accesses to the shared resource, that sends a disconnect message to the second operating system before the first operating system is restarted, that sends a connect message to the second operating system after the first operating system is restarted to inform the second operating system that the first operating system has been restarted, and that sends a resume message to the second operating system after the first operating system is restarted to indicate to the second operating system that the first operating system is ready to resume sharing the shared resource with the second operating system.

2. A computer readable program product having recordable media for storing a first operating system and a second operating system, the program product comprising:

the first operating system owning a shared resource, the first operating system comprising;

a pause/resume mechanism that sends a pause message to the second operating system using the shared resource when the first operating system needs to be restarted, that receives a pause complete message from the second operating system to indicate the second operating system has completed pending accesses to the shared resource, that sends a disconnect message to the second operating system before the first operating system is restarted, that sends a connect message to the second operating system after the first operating system is restarted to inform the second operating system that the first operating system has been restarted, and that sends a resume message to the second operating system after the first operating system is restarted to indicate to the second operating system that the first operating system is ready to resume sharing the shared resource with the second operating system.

3. A computer system comprising:

at least one processor;

a memory coupled to the at least one processor;

a first operating system residing in the memory, the first operating system owning a shared resource;

a second operating system residing in the memory, the second operating system using the shared resource; and

a pause/resume mechanism residing in the memory, the pause/resume mechanism sending a pause message to the second operating system when the first operating system needs to be restarted, the pause/resume mechanism receiving a pause complete message from the second operating system to indicate the second operating system has completed pending accesses to the shared resource, the pause/resume mechanism disconnecting the first operating system from the second operating system before the first operating system is restarted, the pause/resume mechanism reconnecting the first operating system and the second operating system after the first operating system is restarted, the pause/resume mechanism sending a resume message to the second operating system after the first operating system is restarted wherein the resume message indicates that the first operating system is ready to resume sharing the shared resource with the second operating system.

4. A computer readable program product having recordable media for storing a pause/resume mechanism, the program product comprising:

the pause/resume mechanism sends a pause message to a second operating system using a shared resource when a first operating system that owns the shared resource needs to be restarted, the pause/resume mechanism receiving a pause complete message from the second operating system to indicate the second operating system has completed pending accesses to the shared resource, the pause/resume mechanism disconnecting the first operating system from the second operating system before the first operating system is restarted, the pause/resume mechanism reconnecting the first operating system and the second operating system after the first operating system is restarted, the pause/resume mechanism sending a resume message to the second operating system after the first operating system is restarted wherein the resume message indicates that the first operating system is ready to resume sharing the shared resource with the second operating system.