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Hardware requirements

Hardware planning for Superphenix starts from how you deploy availability zones and storage relative to compute, as described in Deployment topology. The same cluster can imply very different server counts and configurations depending on whether you run a hyperconverged stack (storage and virtualization together) or a decoupled stack (dedicated storage and dedicated virtualization clusters).

  • Hyperconverged — Storage and virtualization on the same nodes. Size hosts for combined Ceph and hypervisor needs, plus headroom for failure and recovery.
  • Decoupled — Requirements are split by role:
    • Storage node — Dedicated Ceph / storage tier in a decoupled topology. Same hardware floors as hyperconverged storage roles, sized for OSD throughput and replication.
    • Virtualization nodes — Dedicated hypervisor tier in a decoupled topology. Same CPU, RAM, and boot-disk expectations as hyperconverged compute roles, sized for VM density and migration.

Choose your topology first

Decide which deployment topology you want (hyperconverged or decoupled) before sizing hardware. The hardware requirements tabs below depend on that choice.

Deployment topology is the main factor that influences the requirements:

  • Hyperconverged — Each node contributes to both storage and virtualization. Disk, CPU, and memory requirements are combined on the same machines: size hosts for the sum of what the Ceph storage and the hypervisor need, plus headroom for failure and recovery
  • Decoupled — Requirements split by role. The storage tier must satisfy Ceph expectations for OSD throughput, replication, and recovery; the virtualization tier is sized separately for VM density, live migration, and control-plane overhead. You plan distinct footprints for storage hosts, for hypervisor hosts, and for the management cluster that runs the platform control plane (see Management cluster (decoupled))

Multi-AZ and disaster recovery

If you deploy multiple availability zones and expect disaster recovery between them, plan additional capacity on each AZ beyond steady-state workload. You need room for cross-AZ backup and replication traffic and retention. When an AZ is impaired, you also need room for absorbing or restarting workloads that you fail over or relocate from another zone. Without that margin, a zone sized only for its local peak can become overloaded during recovery or when it must temporarily carry part of a neighbor’s load.


Alignment with Ceph

Superphenix relies on Ceph for block and distributed storage. Treat the official documentation as authoritative for storage nodes:

  • Ceph Hardware Recommendations — CPU per OSD (especially with NVMe), RAM and osd_memory_target headroom, OS vs data devices, enterprise-class SSDs/NVMe and endurance, minimum OSD sizes, and network bandwidth so replication and client I/O do not contend
  • Ceph network configuration referencePublic vs cluster networks, separating client traffic from OSD heartbeat, replication, and recovery

For production performance, prefer enterprise-tier SSDs or NVMe suitable for sustained writes and failure handling, consistent with Ceph’s guidance to avoid consumer-grade drives under heavy or mixed workloads.

Choose your disks carefully

Deploying Ceph on consumer-grade SSDs can lead to reduced performance and high latency. Ceph is very sensitive to how disks acknowledge writes. Always make sure the disks you select are fit for intensive storage usage. Running high-I/O workloads on consumer SSDs can also wear them out quickly.


Hardware requirements

Use the Minimal, Recommended, and Optimal tabs below to compare tiers.

  • Minimal — Floor for labs and early validation; not a long-term production target on its own
  • Recommended — Default production-oriented sizing for typical deployments
  • Optimal — More headroom, higher-bandwidth networking, for when you expect dense storage, large VM counts, aggressive recovery SLAs, or rapid growth

Hyperconverged setup

Aspect Specification
Chassis Physical servers with disks integrated in the chassis
Node count 1
RAM 32 GiB per server
CPU cores 8
CPU architecture x86-64 with Intel VT-x or AMD-V enabled in firmware on hypervisor nodes
Disks (storage) 1 raw disk per node where storage services run; this can't be the boot disk
NIC / link speed 10 Gb/s Ethernet
Boot / OS Fast enterprise SSD acceptable
Storage media Enterprise SSD or NVMe
MTU 1500
Aspect Specification
Chassis Physical servers with disks integrated in the chassis
Node count 3
RAM On the order of 512 GiB for nodes with a lot of VMs; also plan roughly 1 GiB RAM per 1 TiB of Ceph-managed capacity (plus Ceph OSD/daemon RAM per upstream guidance)
CPU cores 32
CPU architecture x86-64 with Intel VT-x or AMD-V enabled in firmware on hypervisor nodes
Disks (storage) 3 raw disks per node
NIC / link speed 2x25Gb/s through active/active bonding
Boot / OS 2× NVMe in RAID 1 for OS
Storage media Enterprise disks, NVMe for VM storage, and HDDs for backups
MTU 9000
Aspect Specification
Chassis Redundant PSUs and clear failure-domain separation (rack/row) where possible
Node count 6
RAM Extra headroom for growth, peak recovery, and large OSD counts; align with Ceph guidance for mon/mgr RAM as the cluster grows
CPU cores ≥ 96 on nodes with very high VM density; favor higher clock
CPU architecture x86-64 with Intel VT-x or AMD-V enabled in firmware on hypervisor nodes
Disks (storage) 8 raw disks per node
NIC / link speed 2 NICs with dual 25Gb/s ports (active/active bonding), with 2 ports dedicated to the storage and 2 dedicated to the data
Boot / OS 2× NVMe in RAID 1 for OS
Storage media Enterprise disks, NVMe for VM storage, and HDDs for backups, with high DWPD
MTU 9000

Decoupled setup

Storage node

Aspect Specification
Chassis Physical servers with disks integrated in the chassis
Node count 3
RAM 80 GiB per server
CPU cores 16
Disks (storage) 8 raw disk per node
NIC / link speed 10 Gb/s Ethernet
Boot / OS Fast enterprise SSD acceptable
Storage media Enterprise SSD or NVMe
MTU 1500
Aspect Specification
Chassis Physical servers with disks integrated in the chassis
Node count 6
RAM 128 GiB per server
CPU cores 32
Disks (storage) 16 raw disk per node
NIC / link speed 2x25Gb/s through active/active bonding
Boot / OS Fast enterprise SSD acceptable
Storage media Enterprise SSD or NVMe
MTU 9000
Aspect Specification
Chassis Physical servers with disks integrated in the chassis
Node count 12
RAM 128 GiB per server
CPU cores 32
Disks (storage) 16 raw disk per node
NIC / link speed 2 NICs with dual 25Gb/s ports (active/active bonding), with 2 ports dedicated to the storage and 2 dedicated to the data
Boot / OS Fast enterprise SSD acceptable
Storage media Enterprise SSD or NVMe
MTU 9000

Virtualization nodes

Aspect Specification
Chassis Physical servers
Node count 1
RAM 32 GiB per server
CPU cores 8
CPU architecture x86-64 with Intel VT-x or AMD-V enabled in firmware on hypervisor nodes
NIC / link speed 10 Gb/s Ethernet
Boot / OS Fast enterprise SSD acceptable
MTU 1500
Aspect Specification
Chassis Physical servers
Node count 3
RAM On the order of 1 TiB for nodes with a lot of VMs; also plan roughly 1 GiB RAM per 1 TiB of Ceph-managed capacity (plus Ceph OSD/daemon RAM per upstream guidance)
CPU cores 32
CPU architecture x86-64 with Intel VT-x or AMD-V enabled in firmware on hypervisor nodes
NIC / link speed 2x25 Gb/s (or faster) for inter-node traffic and storage access
Boot / OS 2× NVMe in RAID 1 for OS
MTU 9000
Aspect Specification
Chassis Redundant PSUs and clear failure-domain separation (rack/row) where possible
Node count 6
RAM Extra headroom for growth, peak recovery, and large OSD counts; align with Ceph guidance for mon/mgr RAM as the cluster grows
CPU cores ≥ 96 on nodes with very high VM density; favor higher clock
CPU architecture Same as recommended
NIC / link speed 2 NICs with dual 25Gb/s ports (active/active bonding), with 2 ports dedicated to the storage and 2 dedicated to the data
Boot / OS Enterprise disks, NVMe for VM storage, and HDDs for backups
MTU 9000

Management cluster (decoupled)

In a decoupled topology, the management cluster is the small Kubernetes cluster that hosts the Superphenix control-plane and operational services separate from your storage and workload virtualization nodes. It does not replace sizing for Ceph or hypervisors; it is an additional slice of machines sized for API controllers, GitOps, monitoring, and related components at modest density.

Aspect Specification
Node count 1
CPU cores 4 per node
RAM 16 GiB per node
Aspect Specification
Node count 3
CPU cores 4 per node
RAM 16 GiB per node

Recommendations

Plan capacity with horizontal growth in mind: Superphenix scales by adding nodes, so when compute nodes or storage nodes become overloaded, expanding the cluster with additional nodes is often the safest and most predictable way to recover headroom.

How large virtualization nodes are should still depend on how many VMs (and other workloads, such as databases, web servers, and inference services) you run and what each VM requests. KSM can reduce effective RAM usage, but treat it as an optimization rather than a sizing baseline. It is enabled by default on all nodes to deduplicate memory between VMs.

Node fleets also do not need to be perfectly uniform: you can safely operate clusters with mixed node configurations, as long as overall capacity and failure-domain planning are respected.

You do not need to get the exact sizing of your clusters right the first time. Superphenix uses the Kubernetes scheduling engine to place workloads across available CPU and RAM on each node as efficiently as possible.