Description of problem: Support an API for shutting down a guest which is less drastic than virDomainDestroy, but more forceful than virDomainShutdown. This lets QEMU safely flush out any pending data & cleanly shutdown. Version-Release number of selected component (if applicable): How reproducible: Steps to Reproduce: 1. 2. 3. Actual results: Expected results: Additional info:
commit 72f8a7f19753506ed957b78ad800c0f3892c9304 Author: Laine Stump <laine> Date: Fri Jan 27 13:28:23 2012 -0500 qemu: new GRACEFUL flag for virDomainDestroy w/ QEMU support When libvirt's virDomainDestroy API is shutting down the qemu process, it first sends SIGTERM, then waits for 1.6 seconds and, if it sees the process still there, sends a SIGKILL. There have been reports that this behavior can lead to data loss because the guest running in qemu doesn't have time to flush its disk cache buffers before it's unceremoniously whacked. This patch maintains that default behavior, but provides a new flag VIR_DOMAIN_DESTROY_GRACEFUL to alter the behavior. If this flag is set in the call to virDomainDestroyFlags, SIGKILL will never be sent to the qemu process; instead, if the timeout is reached and the qemu process still exists, virDomainDestroy will return an error. Once this patch is in, the recommended method for applications to call virDomainDestroyFlags will be with VIR_DOMAIN_DESTROY_GRACEFUL included. If that fails, then the application can decide if and when to call virDomainDestroyFlags again without VIR_DOMAIN_DESTROY_GRACEFUL (to force the issue with SIGKILL). (Note that this does not address the issue of existing applications that have not yet been modified to use VIR_DOMAIN_DESTROY_GRACEFUL. That is a separate patch.)