1. Server requirements

Datacenter SaaS and on-premises Warren deployments require a minimum of 4 servers to offer virtualization-based (no bare-metal) functionality. 

• 3 Control nodes for Warren components. This set of nodes serves on average a cluster with 100 virtualization hosts. 

• 1 Virtualization hosts - hypervisor for VMs .

For more detailed information about cluster configurations, please see: /wiki/spaces/WAR/pages/12944086

2. Servers and Networking Devices models and spec

All servers must have PXE boot capability and IPMI Remote Management Interface. 

Supported CPU manufacturers are Intel, AMD and some models of ARM (Intel is preferable). 

RAM version is not fixed (both DDR3 and DDR4 are supported for each node type)

• Control domain servers - In case of small cluster sizes (less than 20 hypervisors) Xeon x56XX (single or dual CPU) or at least 6-core Xeon E3 and 32GB RAM (expandable to 64GB) per node suffice. For larger clusters, please discuss this matter before Warren deployment is started.

• Virtualization domain servers - Although there are no strictly defined minimum system requirements for virtualization hosts, it is recommended to have 2 x 8-core Xeon E5 (or higher) and 256GB RAM (recommended RAM amount heavily depends on the number of cores in total).
• Networking domain -  Juniper QFX-series switches (5110 oor 5120) and MX-series routers are preferred. (for possible device topology, please see diagrams in /wiki/spaces/WAR/pages/12944086) For other vendors compatibility, please be sure that routers have following options available and configured:
• Dynamic GRE tunnels (MPLS over UDP/GRE)

• VxLAN

• Multiprotocol Extensions for BGP (MBGP or MP-BGP)

• L3VPN

3. Server inter-connectivity

• Five VLAN-s are required:

• management - This network is used to access physical nodes over VPN using SSH. It should be assigned to every physical node. Regular private network.

• storage - This network is used for platform and Ceph communications. It should be assigned to control nodes, hypervisors and Ceph monitors. Usually Ceph refers as "Ceph public" or "Ceph client" network. Regular private network.

• ceph_private - This network is used for Ceph internal communications. It should be assigned only to Ceph nodes.
• tungsten - This network is used for virtual machine networking. It should be assigned to all control nodes, all hypervisors and to SDN gateway router (juniper MX/vMX or Cisco ASR etc)
• public - This network is used for public access to platform (web UI and API). It should be assigned to control nodes only.

• There are no strict requirements on networking equipment manufacturers (Juniper and Mellanox are preferred).

• NIC requirements:

• For Control domain servers, at least 2 extension NICs, one of which must be 10GbE or 25GbE (dual-port recommended)

• For Virtualization domain servers, at least 2 extension NICs, both 10GbE or 25GbE(dual-port recommended to separate virtual machine networking from storage).

• Additionally, for management and hardware monitoring purposes, all servers must include at least 1 NIC, 1GbE.

4. Storage

• As a system storage, both, Control domain and Virtualization domain require:
  

  • At least 2 x 500 GB SSD or NVMe in RAID 1 as a boot storage

• Control domain additionally require:

  • At least 2 TB SSD or NVMe for Warren components and caching

• As a user storage for Virtualization domain, at least one of the following storage types is a strong requirement:

  • Distributed storage (e.g. CEPH)

• Other user storage types are in BETA stage and will be available in the future:

  • Local storage of SSD or NVMe in RAID 10

  • Enterprise storage solution (e.g. 3PAR)

5. Software

• All servers should come with NixOS 20.09 Installed
• All servers should have VLAN-s configured and named as stated in Server inter-connectivity chapter (only exception is ceph_private VLAN, this name can be chosen freely).