hypervisor selection in cloudstack

Tim Mackey – XenServer Community Evangelist

Hypervisor Selection in Cloud Understanding the choices available

CloudStack Collaboration Conference Europe 2013

Building a successful cloud What are we trying to accomplish?

© Citrix 2013. More information at xenserver.org and follow me on twitter @XenServerArmy

Service Offerings

• Clearly define what you want to offer ᵒ What types of applications

ᵒ Who has access, and who owns them

ᵒ What type of access

• Define how templates need to be managed ᵒ Operating system support

ᵒ Patching requirements

• Define expectations around compliance and availability ᵒ Who owns backup and monitoring


Define Tenancy Requirements

• Department data local to department ᵒ Where is the application data stored

• Data and service isolation ᵒ VM migration and host HA

ᵒ Network services

• Encryption of PII/PCI ᵒ Where do keys live when data location unknown

ᵒ Need encryption designed for the cloud

• Showback to stakeholders ᵒ More than just usage, compliance and audits


Virtualization Infrastructure

• Hypervisor defined by service offerings ᵒ Don’t select hypervisor based on “standards”

ᵒ Understand true costs of virtualization

ᵒ Multiple hypervisors are “OK”

ᵒ Bare metal can be a hypervisor

• To “Pool” resources or not ᵒ Is there a real requirement for pooled resources

ᵒ Can the cloud management solution do better?

ᵒ Real cost of shared storage

• Primary storage defined by hypervisor

• Template storage defined by solution ᵒ Typically low cost options like NFS

The primary choices ….


Networking Storage Compute

XenServer

Xen Project Hypervisor

Standard Linux Distribution (dom0)

qemu drivers

xapi

Guest

Driver front

Driver back

Guest

Driver front

patches


KVM (Linux + KVM only)

Standard Linux Distribution

qemu drivers

Guest

Virtual driver

virtio

Guest

Virtual driver

KVM Module

libvir

t

agent



vSphere 5.1 Managed by vCenter

vmkernel

Guest

Virtual driver

vSCSI

Guest

Virtual driver

Task

Scheduler

Service

Console

vmklinux vC

ente

r

drivers

vNIC



Linux Containers

Standard Linux Distribution

Namespace

Container

Namespace

Container

KVM Module

libvir

t

agent Cgroups

Cgroup Cgroup

Namesspaces


Defining the network


Flat Network – Basic Layer 3 Network

Feature XenServer vSphere KVM LXC

Security Groups Yes- bridge No Yes Yes

IPv6 No No Yes Yes

Multiple IPs per NIC

Yes Yes Yes Yes

Nicira NVP Yes No Yes No

BigSwitch VNS Yes No Yes No

65.11.1.2

65.11.1.3

65.11.1.4

65.11.1.5

Public Network 65.11.0.0/16

Guest VM 1

Guest VM 2

Guest VM 3

Guest VM 4

DHCP, DNS

CloudStack Virtual Router

Security Group 1

Security Group 2


VLANs for Private Cloud

10.1.1.1

10.1.1.3

10.1.1.4

10.1.1.5

Public Network/Internet

Guest Virtual Network 10.0.0.0/8 VLAN 100

DHCP, DNS NAT Load Balancing VPN

Public IP 65.37.14.1

Gateway 10.1.1.1

Guest VM 1

Guest VM 2

Guest VM 3

Guest VM 4

CloudStack Virtual Router


Max VLANs 800 254 1024 1024

IPv6 No No Yes Yes

Multiple IPs per NIC

Yes Yes Yes Yes

Nicira NVP Yes No Yes No

BigSwitch VNS Yes No Yes No

MidoKura No No Yes No

VPC Yes Yes Yes No

NetScaler Yes Yes Yes No

F5 BigIP Yes Yes Yes No

Juniper SRX No Yes Yes No

Cisco VNMC No Yes No No


Beyond the VLAN – Network Virtualization


OVS GRE tunnels Yes No No No

Nicira STT tunnel Yes No Yes No

MidoNet No No Yes No

VXLAN No Yes No No

NVGRE No No No No

Nexus 1000v No Yes No No


Virtual Private Cloud and nTier Applications

Web

App

DB

Router

DC1

DC2 DC3

DC4

DC5

DC6

VLAN 1

VLAN 2

VLAN 3

S2S VPN

Private

GW


PVLAN Yes - ovs Yes ovs No


Delivering specific network services

• IPv6 KVM is your only virtualized option (basic or advanced)

• Maximum VLANs XenServer or KVM are your best options

• Security Groups XenServer or KVM are your options

• VXLAN requires vSphere Enterprise Plus

• Cisco Nexus 1000v and ASA 1000v require vSphere Enterprise Plus

Instances need a home Storage, Storage and more Storage


Primary Storage Options


Local storage Yes Yes Yes Yes

NFS Yes Yes Yes Yes

Single path iSCSI Yes Yes Yes No

Multipath iSCSI PreSetup No No No

Direct array No VAAI No No

Shared Mount No No Yes Yes

Template format VHD OVA QCOW2 TAR

Cluster

Host

Host

Primary Storage

Core virtualization capabilities The limits and features which matter


CloudStack Features


Disk IO Statistics Yes No Yes

Memory Overcommit Yes (4x) Yes No No

Dedicated resources Yes Not with HA/DRS Yes No

Disk IO throttling No No Yes Yes

Disk snapshot (running) Yes Yes No No

Disk snapshot (Stopped) Yes Yes Yes No

Memory snapshot Yes Yes Yes No

Zone wide primary storage No Yes Yes Yes

Resize disk Offline Online Grow Online No

High availability CloudStack Native CloudStack No


XenServer 6.2

Feature

Source code model Open Source (GPLv2)

Maximum VM Density 650

CloudStack VM Density 150

CloudStack integration Direct XAPI calls

Maximum native cluster Size 16

Maximum pRAM 1 TB

Largest VM 16vCPU/128GB

Windows Operating System All Windows supported by Microsoft

Linux Operating Systems RHEL, CentOS, Debian, Ubuntu, SLES, OEL

Advanced features supported ovs, Storage XenMotion, DMC


vSphere 5.1 (vSphere 5.5 not supported)

Feature

Source code model Proprietary

Maximum VM Density 512


CloudStack integration vCenter

Maximum native cluster Size 32

Maximum pRAM 2 TB

Largest VM 64 vCPU/1TB

Windows Operating Systems DOS, All Windows Server/Client

Linux Operating Systems Most

Advanced features supported HA, DRS, DVS, Storage vMotion


KVM (RHEL/CentOS 6.3 and Ubuntu 12.04)

Feature


Maximum VM Density 10 times the number of pCores


CloudStack integration CloudStack Agent (libvirt)

Maximum native cluster size No native cluster support

Maximum pRAM 2 TB

Largest VM

Windows Operating Systems

Linux Operating Systems

Advanced features supported None


Linux Containers

Feature


Maximum container Density 6000 (theoretical)

CloudStack container Density 50

CloudStack integration CloudStack Agent (libvirt), requires KVM for SVMs

Maximum native cluster size N/A

Maximum pRAM 2 TB

Largest container 2TB

Windows Operating Systems N/A

Linux Operating Systems Kernel compatible distros

Picking the “best one” When to use which hypervisor…


KVM

• Primary value proposition: ᵒ Low cost with available vendor support

ᵒ Familiar administration model

ᵒ Broad CloudStack feature set with active development

• Cloud use cases: ᵒ Linux centric workloads

ᵒ Dev/test clouds

ᵒ Web hosting

ᵒ Tenant density which dictates SDN options

• Weaknesses: ᵒ Requires use of an installed CloudStack libvirt agent

ᵒ Limited native storage options

ᵒ No use of advanced native features


Linux Containers


ᵒ Familiar administration model

• Cloud use cases: ᵒ Dev/test clouds

ᵒ Web hosting

• Weaknesses: ᵒ Requires use of an installed CloudStack libvirt agent

ᵒ Requires KVM for system VMs

ᵒ No use of advanced native features


vSphere

• Primary value proposition: ᵒ Broad application and operating system support

ᵒ Readily available pool of vSphere administration talent

ᵒ Large eco-system of vendor partners

ᵒ Many CloudStack features are native implementations

ᵒ Direct feature integration via vCenter

• Cloud use cases: ᵒ Private enterprise clouds

ᵒ Dev/test clouds

• Weaknesses: ᵒ vSphere up-front license and ongoing support costs

ᵒ vCenter integration requires redundant designs

ᵒ Single data center per zone model


XenServer


ᵒ Broad CloudStack feature set with active development

ᵒ Large CloudStack install base

ᵒ Direct integration via XAPI toolstack

• Cloud use cases: ᵒ Linux centric workloads

ᵒ Dev/test clouds

ᵒ Web hosting

ᵒ Desktop as a Service clouds

ᵒ Large VM and tenant

• Weaknesses: ᵒ Minimal use of advanced native features


What About Multiple Hypervisor Support?

• vSphere Datacenter must be contained within a single zone

• Force system VMs to a specific hypervisor type

• HA won’t migrate between hypervisors

• Zone wide primary storage doesn’t support multiple hypervisors

• Capacity planning at the cluster/pod level more difficult

Work better. Live better.

hypervisor selection in cloudstack

Technology

dns citrix

vnoyesnono citrix

nfs citrix

monitoring citrix

audits citrix

kvm linux

hypervisor template

virtual private cloud