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Compute Node - KVM / ESXi Architecture

asked 2015-12-26 09:00:50 -0500

anonymous user


Am starting to learn openstack. My understanding (after reading all the docs) is that the compute nodes run a host OS (ubuntu or other linux) and on top of that you have your hypervisor (like KVM) and then the VMs run on top of it i.e HW -> OS -> Hypervisor -> VMs . This is similar to having a VM running on Virtualbox which runs on a host operating system i.e HW-> Host OS ->VBox -> VMs. Please correct me if my understanding is incorrect.

Assuming my first understanding is correct, How will the performance of the VMs on the this architecture be compared to running the VMs directly on hypervisor i.e HW-> Hypervisor (KVM)->VMs ?

Comparing this with VMWare openstack architecture where Nova speaking to VMWare vCenter and then vCenter manages the ESXi nodes (vCenter and ESXi on different nodes). This way my VMs are directly running on top of hypervisor connected to HW (HW->ESXi->VMs).And all the overlay networking is handled by NSX. This looks much more performant compared to the other architecture. Am i missing something here ?

Thanks in advance.

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It is not correct to compare two different type of hypervisors: KVM and VirtualBox. VirtualBox - is a desktop hypervisor of type 2 - useful only when user logged on its desktop. KVM - is a server hypervisor type 1 - useful in servers when you don't need to logon on server.

Ramirezkiv gravatar imageRamirezkiv ( 2015-12-29 02:17:44 -0500 )edit

OpenStack with KVM - is a solution to organize a IAAS environment through several servers with High Availability feature in cluster terms. VitualBox doesn't allow you to deploy a cluster and to manage it effectively. VirtualBox - is for desktops. OpenStack and KVM - are for set of servers.

Ramirezkiv gravatar imageRamirezkiv ( 2015-12-29 02:20:05 -0500 )edit

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answered 2015-12-28 03:25:43 -0500

Prateek K gravatar image

See what the point is when we talk about hypervisor there are a lot of options in the market. Now when it comes to KVM it is the most recommended hypervisor as it is free, fast, provides almost bare level hypervisor kind of performance.

Openstack community also supports KVM hypervisor and there is active development being done in it. There is also ironic which is a bare metal hypervisor provided by openstack which can also be used.

Now the big question comes as to which hypervisor to choose. That purely depends upon your use-case as to what all features you want for the hypervisor to perform .. See this matrix for full feature support :-

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Thanks.I will read more about "Ironic".

vpel4 gravatar imagevpel4 ( 2015-12-28 22:04:16 -0500 )edit

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Asked: 2015-12-26 08:58:25 -0500

Seen: 6,242 times

Last updated: Dec 28 '15