Proxmox VE + CEPH for VDI

Felix_C

New Member
Sep 11, 2025
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Hi everyone,

I am reaching out because this is the first time I am sizing a cluster using Proxmox VE and Ceph. Since I lack direct experience with these solutions, I would appreciate your feedback on my proposal.

The cluster will support a VDI environment. Based on the workload profile we are targeting, these are the resources required for 100 concurrent users:
  • vCPU: 910
  • RAM GB: 3.500
  • Disk TB: 20
  • GPU GB: 800

I was unable to find a Ceph sizing calculator that accounted for both usable capacity and resource overhead (CPU/RAM consumption), so I developed the following calculations based on the Ceph sizing parameters I researched.

Proposed servers resources
  • CPU (2 x 64 Cores) (vCPU 2 to 1): 128
  • RAM GB: 1.024
  • Disk TB (6 x 3.2TB NVME MU): 19,2
  • GPU GB (NVIDIA L4 24GB): 192
Number of servers: 6


CEPH Sizing

RAW Storage TB (6 x 19,2): 115,2

Number of replicas: 3

Usable Storage TB: 38,4

Safe nearfull ratio: 0,8

REAL Usable Storage TB: 30,72

CEPH RAM requirements: 180
CEPH CPU requirements: 30


Based on the Ceph resource consumption shown above, these are the total estimated resources required for the cluster:

100 Users + CEPH resource requirements
  • vCPU: 970
  • RAM GB: 3.680
  • Disk TB: 20
  • GPU GB: 800


And here are the total hardware specs for the proposed 6-node cluster:

Cluster HW Total resources
  • vCPU (2 to 1): 1.536
  • RAM GB: 6.144
  • Disk TB: 38
  • GPU GB (NVIDIA L4 24GB): 1152

I am assuming a hypervisor overhead of approximately 10% for Proxmox.

  • vCPU (2 to 1): 1.382
  • RAM GB: 5.530
  • Disk TB: 30,7
  • GPU GB (NVIDIA L4 24GB): 1152


The following represent the usable resources after accounting for the overhead and maintaining a reasonable 80% utilization threshold:

  • vCPU (2 to 1): 1.106
  • RAM GB: 4.424
  • Disk TB: 30,7
  • GPU GB (NVIDIA L4 24GB): 921


If my sizing is correct, the total node count should be 6 + 1 for High Availability, taking into account the workload requirements and Ceph resource consumption.


Regarding networking:
  • Ceph Back-end/Storage Traffic: I am planning to use two dual-port 25GbE NICs.
  • Front-end/Client Connectivity: I am planning to use two dual-port 10GbE NICs.

Are there any additional considerations or best practices I should keep in mind for this specific sizing?

Thanks for your help.
 
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