[Libvir] [patch 8/9] Implement better signal handling

[Daniel P. Berrange]

On Sat, Feb 17, 2007 at 01:22:35PM +0000, Mark McLoughlin wrote:
> On Fri, 2007-02-16 at 19:08 +0000, Daniel P. Berrange wrote:
> > On Fri, Feb 16, 2007 at 02:44:46PM +0000, Mark McLoughlin wrote:
> > > Handle SIGHUP by shutting down all guests and networks
> > > and re-loading configs
> > 
> > This violates the 'principle of least surprise'. I certainly do not expect
> > a config file reload to terminate all active guests. Since QEMU is a full
> > virt system, there is no graceful shutdown process, and so this is equivalent
> > to ripping the power cable out of all your VMs. IMHO this makes SIGHUP
> > essentially useless.
> > 
> > We already have the ability to store a secondary config against any active
> > guest VMs, which will be automatically activated upon next boot of the 
> > guest - this is how we let virDefineDomain()  override the config of an
> > existing VM.  IMHO, sending SIGHUP to the daemon should just scan for
> > config files and if any VMs are active, load into the secondary config.
> 
> 	All good points, fixed now with the attached patch.

Looks good - simpler than I expected it to be - I forgot that the 
qemudScanConfigs function would already do the right thing if being
run over.

> > > Handle SIGTERM/SIGINT by cleanly shutting down
> > 
> > Ack, this is desirable. We should also hook in SIGQUIT
> 
> 	Yep, done.

Dan.
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