39 Requirements & Assumptions #

39.1 Hardware #

The hardware requirements for SUSE Telco Cloud are as follows:

Management cluster: The management cluster contains components like SUSE Linux Micro, RKE2, SUSE Rancher Prime, Metal³, and it is used to manage several downstream clusters. Depending on the number of downstream clusters to be managed, the hardware requirements for the server could vary.
- Minimum requirements for the server (VM or bare-metal) are:
  - RAM: 8 GB Minimum (we recommend at least 16 GB)
  - CPU: 2 Minimum (we recommend at least 4 CPU)
Downstream clusters: The downstream clusters are the clusters deployed to run Telco workloads. Specific requirements are needed to enable certain Telco capabilities like SR-IOV, CPU Performance Optimization, etc.
- SR-IOV: to attach VFs (Virtual Functions) in pass-through mode to CNFs/VNFs, the NIC must support SR-IOV and VT-d/AMD-Vi be enabled in the BIOS.
- CPU Processors: To run specific Telco workloads, the CPU Processor model should be adapted to enable most of the features available in this reference table (Chapter 41, Telco features configuration).
- Firmware requirements for installing with virtual media:

Server Hardware	BMC Model	Management
Dell hardware	15th Generation	iDRAC9
Supermicro hardware	01.00.25	Supermicro SMC - redfish
HPE hardware	1.50	iLO6

39.2 Network #

As a reference for the network architecture, the following diagram shows a typical network architecture for a Telco environment:

The network architecture is based on the following components:

Management network: This network is used for the management of downstream cluster nodes. It is used for the out-of-band management. Usually, this network is also connected to a separate management switch, but it can be connected to the same service switch using VLANs to isolate the traffic.
Control-plane network: This network is used for the communication between the downstream cluster nodes and the services that are running on them. This network is also used for the communication between the nodes and the external services, like the DHCP or DNS servers. In some cases, for connected environments, the switch/router can handle traffic through the Internet.
Other networks: In some cases, nodes could be connected to other networks for specific purposes.

Note

To use the directed network provisioning workflow, the management cluster must have network connectivity to the downstream cluster server Baseboard Management Controller (BMC) so that host preparation and provisioning can be automated.

39.3 Services (DHCP, DNS, etc.) #

Some external services like DHCP, DNS, etc. could be required depending on the kind of environment where they are deployed:

Connected environment: In this case, the nodes will be connected to the Internet (via routing L3 protocols) and the external services will be provided by the customer.
Disconnected / air-gap environment: In this case, the nodes will not have Internet IP connectivity and additional services will be required to locally mirror content required by the directed network provisioning workflow.
File server: A file server is used to store the OS images to be provisioned on the downstream cluster nodes during the directed network provisioning workflow. The Metal³ Helm chart can deploy a media server to store the OS images — check the following section (Note), but it is also possible to use an existing local webserver.

39.4 Disabling systemd services #

For Telco workloads, it is important to disable or configure properly some of the services running on the nodes to avoid any impact on the workload performance running on the nodes (latency).

rebootmgr is a service which allows to configure a strategy for reboot when the system has pending updates. For Telco workloads, it is really important to disable or configure properly the rebootmgr service to avoid the reboot of the nodes in case of updates scheduled by the system, to avoid any impact on the services running on the nodes.

Note

For more information about rebootmgr, see rebootmgr GitHub repository.

Verify the strategy being used by running:

cat /etc/rebootmgr.conf
[rebootmgr]
window-start=03:30
window-duration=1h30m
strategy=best-effort
lock-group=default

and you could disable it by running:

sed -i 's/strategy=best-effort/strategy=off/g' /etc/rebootmgr.conf

or using the rebootmgrctl command:

rebootmgrctl strategy off

Note

This configuration to set the rebootmgr strategy can be automated using the directed network provisioning workflow. For more information, check the Automated Provisioning documentation (Chapter 42, Fully automated directed network provisioning).

transactional-update is a service that allows automatic updates controlled by the system. For Telco workloads, it is important to disable the automatic updates to avoid any impact on the services running on the nodes.

To disable the automatic updates, you can run:

systemctl --now disable transactional-update.timer
systemctl --now disable transactional-update-cleanup.timer

fstrim is a service that allows to trim the filesystems automatically every week. For Telco workloads, it is important to disable the automatic trim to avoid any impact on the services running on the nodes.

To disable the automatic trim, you can run:

systemctl --now disable fstrim.timer