I am considering to use Microcloud as foundation for our prepared SaaS solution. First we would like to create test/lab environment with three nodes with following specs:
8 core AMD CPU
32GB RAM
1 x 128GB SSD for OS
1 x 1TB SSD for local storage
1 x 1TB SSD for remote storage
1x 1Gbps Ethernet card for uplink
1 x 1Gbps Ethernet card for OVN
What we would like to test:
Footprint of the solution
Deployment of Juju Charmed PostgreSQL and our SaaS software (we will very likely create Charm for our software)
Test of scaling, backup, recovery of Charmed PostgreSQL and our SaaS software
Test adding a machine
Migration of VM/container in case of failure of the machine
Disaster recovery of the Microcloud
Questions:
Are specs for lab environment OK?
Any examples of production setup, including network devices specs (switches, routers)?
In which cases the interconnect 1Gbps network will limit the performance of the lab environment? Just in case of migration of the VM’s from failed machine, or other cases as well?
Any practical tips/references to test scenarios I mentioned?
The specs seem to be fine for a lab environment. Are you aware of the hardware requirements section in the MicroCloud docs?
When it comes to the configuration of the networks note the following:
You have mentioned that each of the nodes will have two physical NICs. If I understood you right one of them will be used as the OVN uplink and the other one acts the actual uplink for the node. Note that this link will also be used for OVN underlay (geneve tunnels) and Ceph storage traffic (public/internal) in between the three nodes. This traffic is named as “intra-cluster” on the network requirements doc page.
This means if you put lots of pressure onto the storage devices (using Ceph remote storage pool) this might have side effects on the OVN overlay networks as they share the same NIC across the cluster. Same happens the other way around.
Have a look a the Ceph networking doc page for a more detailed view on the different networks and configuration options.
The NIC used for intra-cluster traffic needs to have an IP address assigned. The OVN uplink interface has to be unconfigured but UP so MicroCloud can pick it up during initialization of the cluster.
In general we recommend 10G NICs for prod setups. For this please refer to the docs page.
As long as you use the remote storage pool the live migration of VMs is fairly “light weight” as you don’t have to transfer the VMs root volume in between the two nodes.