On Mon, Oct 05, 2020 at 07:12:34PM -0400, Digimer wrote:>On 2020-10-05 6:04 p.m., Lentes, Bernd wrote: >> Hi, >> >> what does "virsh destroy" with the domain ? Send a kill -9 to the process ? >> >> Bernd >> > >It forces the guest off, like pulling the power on a hardware machine. >Not sure of the exact mechanism behind the scenes. It does leave the >server defined and you can reboot it again later (albeit like restoring >power to a normal machine, so it might need to replay journals, etc). >The technical details should not matter, but it tries to send "quit" to QEMU and falls back to killing it IIRC (firsh with SIGTERM and then with SIGKILL). Don't do that if you want to use the machine again ;-)>-- >Digimer >Papers and Projects: https://alteeve.com/w/ >"I am, somehow, less interested in the weight and convolutions of >Einstein’s brain than in the near certainty that people of equal talent >have lived and died in cotton fields and sweatshops." - Stephen Jay Gould > >
On Tue, Oct 06, 2020 at 09:15:57AM +0200, Martin Kletzander wrote:> On Mon, Oct 05, 2020 at 07:12:34PM -0400, Digimer wrote: > > On 2020-10-05 6:04 p.m., Lentes, Bernd wrote: > > > Hi, > > > > > > what does "virsh destroy" with the domain ? Send a kill -9 to the process ? > > > > > > Bernd > > > > > > > It forces the guest off, like pulling the power on a hardware machine. > > Not sure of the exact mechanism behind the scenes. It does leave the > > server defined and you can reboot it again later (albeit like restoring > > power to a normal machine, so it might need to replay journals, etc). > > > > The technical details should not matter, but it tries to send "quit" to QEMU and > falls back to killing it IIRC (firsh with SIGTERM and then with SIGKILL). Don't > do that if you want to use the machine again ;-)You don't need to be so scared of virsh destroy. It is simply akin to pulling out the power plug, and modern OS with a decent journaling filesystem will recover from that quite reasonably. Sure you'll loose state of what's running, but 99% of the time your guest will boot up again just fine. Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|
On 06.10.20 10:16, Daniel P. Berrangé wrote:> > You don't need to be so scared of virsh destroy. It is simply akin to pulling > out the power plug, and modern OS with a decent journaling filesystem will > recover from that quite reasonably. Sure you'll loose state of what's running, > but 99% of the time your guest will boot up again just fine.In case one of our (many) VMs crash we "destroy" it. We never experiencend any Problem you would not expect in case of physical server crashes. Over the last 10 years this happened more than 1000 times... Michael