Atlas of global Apache CloudStack configuration variables, defined at the cluster level

The article describes not all the parameters, but only those that you usually need to change when configuring new CloudStack clouds. The settings for the cluster are applied without restarting the CloudStack management servers and only affect the cluster for which it is installed.

CloudStack Version: 4.11.1

The parameters descibed in the article can be configured at: Infrastructure / Clusters / Cluster Name / Settings Tab

cluster.cpu.allocated.capacity.disablethreshold

  • Proposed value: 0.99
  • The amount of allocated cluster’s CPU resources that the cluster stops participating in the resource pool when new machines are allocated. If you use a large number of cores, then even 1% will be quite a significant resource.

cluster.cpu.allocated.capacity.notificationthreshold

  • Proposed value: 0.95
  • The amount of allocated cluster’s CPU resources that CloudStack will notify the administrator of high usage.

cluster.memory.allocated.capacity.disablethreshold

  • Proposed value: 0.99
  • Resource amount of the cluster’s RAM, at which the cluster ceases to participate in the resource pool when new machines are allocated. If you use a large amount of memory, then even 1% will be quite a significant resource.

cluster.memory.allocated.capacity.notificationthreshold

  • Proposed value: 0.95
  • Resource amount of the cluster’s RAM, at which CloudStack notifies the administrator about high usage.

cluster.storage.allocated.capacity.disablethreshold

  • Proposed value: 0.99
  • The amount of the cluster’s storage system usage, at which the cluster ceases to participate in the resource pool when new machines are allocated. If you use a large amount of disk space, then even 1% will be quite a significant resource.

cluster.storage.allocated.capacity.notificationthreshold

  • Proposed value: 0.95
  • The amount of the cluster’s storage system usage, at which CloudStack notifies the administrator of the high level of occupancy.

cpu.overprovisioning.factor

  • Proposed value: 1+
  • This parameter determines how the available total frequency of all CPUs in the cluster will be multiplied, for example, if you specify “2”, then Apache CloudStack multiplies by 2 when calculating the available resources. If you want to completely eliminate the CPU parameter from the calculation, put, for example, 100. Then in the cluster there will be almost unlimited CPU. This can be used if the virtual machines in this cluster are allocated by available RAM, and the CPU is never a limiter (as is often the case with general-purpose machines). For clusters that run highly loaded VMs, this option should be set to “1” or lower if you do not rely on Hyper Threading.

mem.overprovisioning.factor

  • Proposed value: 1.0
  • This parameter determines over-subscription for memory. It should not need to be changed, because as a result, because VMs will simply receive less memory (at least for KVM hypervisor). To override the memory available on a node, you must use other mechanisms. E.g. for KVM in /etc/cloudstack/agent/agent.properties: host.overcommit.mem.mb – useful when using zSwap, ZRAM, fast swap partitions.

Other cluster settings have “good” default values and, usually, do not require modification.