**Apache CloudStack** is a mature open source IaaS cloud platform that provides compute, networking, and storage orchestration. It has a strong track record in Asia-Pacific and among managed service providers who value its simpler operational model and built-in multi-tenancy.
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### First Principle: Multi-tenancy should be a first-class design constraint, not an afterthought.
CloudStack was built for service providers from the ground up. Its zone/pod/cluster hierarchy and account/domain model make it natural for MSPs offering cloud services to multiple independent customers.
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### Key Considerations
- **Zone/Pod/Cluster Model**: CloudStack organises resources hierarchically — Zones (data centers), Pods (racks/rows), Clusters (groups of homogeneous hosts). This maps naturally to physical data center topology.
- **Hypervisor Support**: Supports [[KVM]], VMware vSphere, XenServer, and Hyper-V. One of the few open source platforms with solid commercial hypervisor support.
- **Managed Service Providers**: Powers platforms at Leaseweb, Ikoula, and several Asian cloud providers. Its billing and isolation features make it popular with hosting companies.
- **EC2-Compatible API**: Provides an AWS EC2-compatible API — simplifying migration of tools built against AWS.
- **vs [[OpenStack]]**: Less community/ecosystem size, but simpler to deploy and maintain for MSP use cases.
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### How It Fits
```
[[MAAS]] or manual provisioning
→ Apache CloudStack (IaaS orchestration)
→ [[KVM]] / XenServer (hypervisors)
→ [[Ceph]] or NFS storage
```
[[OpenStack]] | [[OpenNebula]] | [[KVM]] | [[Ceph]] | [[Open Source Hyperscaler MoC]]