Wondering, how do you get devcloud-kvm work?
> -----Original Message----- > From: Marcus Sorensen [mailto:shadow...@gmail.com] > Sent: Friday, February 08, 2013 10:02 AM > To: Alex Huang > Cc: Sebastien Goasguen; Wido den Hollander; cloudstack- > d...@incubator.apache.org > Subject: Re: QEMU support in CloudStack > > I'm running a quick sanity test here... just seeing if switching out kvm with > qemu works, all else the same. Looks like there's a setHvsType for the > LibvirtVMDef as well, that's hardcoded to 'kvm'. > That should be easy to adjust as well, assuming everything just runs with > these changes. > > On Fri, Feb 8, 2013 at 10:54 AM, Alex Huang <alex.hu...@citrix.com> wrote: > > In that case, why not create two resources with the kvm resource > extending the qemu resource and do what Marcus suggests here in the > qemu resource? > > > > Effectively then we have an agent for qemu and one for kvm and they each > can carry their own capabilities. > > > > --Alex > > > >> -----Original Message----- > >> From: Marcus Sorensen [mailto:shadow...@gmail.com] > >> Sent: Friday, February 08, 2013 9:41 AM > >> To: Sebastien Goasguen > >> Cc: Wido den Hollander; cloudstack-dev@incubator.apache.org > >> Subject: Re: QEMU support in CloudStack > >> > >> You would in theory have to disable the check in the agent startup > >> code that looks for the kvm kernel modules, and then libvirt should > >> just fall back to qemu for everything automatically. > >> > >> In LibvirtComputingResource.java, comment out the check for > >> IsHVMEnabled, and then rmmod any kvm modules, then try to do stuff > >> with that version of cloudstack. > >> > >> On Fri, Feb 8, 2013 at 10:10 AM, Sebastien Goasguen > >> <run...@gmail.com> > >> wrote: > >> > > >> > On Feb 8, 2013, at 3:07 PM, Wido den Hollander <w...@widodh.nl> > wrote: > >> > > >> >> Hi, > >> >> > >> >> On 02/08/2013 10:34 AM, Dave Cahill wrote: > >> >>> Hi, > >> >>> > >> >>> Recently I encountered two "nested virtualization" use cases > >> >>> which > >> made me > >> >>> want QEMU hypervisor support in CloudStack. I'm interested to > >> >>> hear if anyone else is interested in this feature, and any notes > >> >>> on how it should be implemented. > >> >>> > >> >>> Here is a good explanation from OpenStack docs [2] on why they > >> support QEMU: > >> >>> "From the perspective of the Compute service, the QEMU hypervisor > >> >>> is > >> very > >> >>> similar to the KVM hypervisor. Both are controlled through > >> >>> libvirt, both support the same feature set, and all virtual > >> >>> machine images that are compatible with KVM are also compatible > >> >>> with QEMU. The main > >> difference is > >> >>> that QEMU does not support native virtualization. Consequently, > >> >>> QEMU > >> has > >> >>> worse performance than KVM and is a poor choice for a production > >> >>> deployment." > >> >>> > >> >> > >> >> So, I've been reading into the code and found this on my Ubuntu > systems. > >> >> > >> >> root@stack01:~# ls -l /usr/bin/kvm lrwxrwxrwx 1 root root 18 Oct > >> >> 4 02:44 /usr/bin/kvm -> qemu-system- > >> x86_64 > >> >> root@stack01:~# > >> >> > >> >> Imho Qemu is Qemu and KVM only comes into play when the kernel > >> module 'kvm' and 'kvm_amd' or 'kvm_intel' is loaded. > >> >> > >> >>> Here are the use cases I encountered: > >> >>> > >> >>> [Use case: Dev environment] > >> >>> Wanted to use Vagrant [1] to create a portable multi-node dev > >> >>> environment; however Vagrant uses VirtualBox, which doesn't > >> >>> support > >> KVM. > >> >>> Also, devcloud uses VirtualBox and devcloud-kvm uses > >> >>> kvm-within- > >> kvm. I > >> >>> imagine maintenance of devcloud and devcloud-kvm would be easier > >> >>> if devcloud-kvm could use VirtualBox too. > >> >>> Note: Of course, I'm aware of devcloud-kvm as an alternative > >> >>> for this use case, and I'll be looking into that next. > >> >>> > >> >>> [Use case: Demo environment] > >> >>> We may want to spin up a multi-node CloudStack install in > >> >>> Amazon > >> AWS > >> >>> for demo purposes. > >> >>> Again, AWS instances don't support KVM, so this is not > >> >>> possible > >> without > >> >>> QEMU support. > >> >>> > >> >>> [Implementation ideas] > >> >>> The management server currently does a check for KVM support > >> ("kvm-ok") > >> >>> on the host, and refuses to add the host if that fails. I think > >> >>> this check could be removed, as the agent setup scripts will fail > >> >>> anyway if the user is trying to setup a certain hypervisor on a > >> >>> machine which doesn't > >> support > >> >>> it. > >> >> > >> >> This way you could do nested virtualization indeed, but it could > >> >> also hurt > >> users who have their BIOS set to disabled and could lead to long > debugging. > >> >> > >> >>> Create a new setting in agent.properties like "use_qemu", > >> >>> with a default of "false". If the person deploying CloudStack > >> >>> agent sets this to "true", cloud-setup-agent and other setup > >> >>> scripts would ignore lack of > >> KVM > >> >>> support as long as QEMU support was available. > >> >> > >> >> cloud-setup-agent generates a agent.properties, so at that point > >> >> it > >> doesn't know that the user intents to use the system without KVM > support. > >> >> > >> >>> Lastly, when creating the libvirt XML file for a VM, set > >> >>> hypervisor to QEMU rather than KVM in the XML file depending on > the config setting. > >> >>> > >> >> > >> >> That's not hard coded. The Agent does a getCapabilities() call to > >> >> libvirt > >> which returns a list of possible emulators. > >> >> > >> >> /usr/bin/kvm is just one of them which is returned and matches the > >> architecture. > >> >> > >> > > >> > Wido, > >> > > >> > So can I add a "KVM" host that would in fact just use qemu ? > >> > How would I do that ? > >> > > >> > -sebastien > >> > > >> > > >> >> Wido > >> >> > >> >>> Thanks for reading, > >> >>> Dave. > >> >>> > >> >>> [1] http://www.vagrantup.com/ > >> >>> [2] > >> >>> http://docs.openstack.org/trunk/openstack- > >> compute/install/yum/content/qemu.html > >> >>> > >> >> > >> >
