Creating a cluster

A cluster is a group of servers in a single location. The key feature of such servers (cluster nodes) is their location and high data transfer speed between them.

Perform the following steps to create a cluster:

1. Go to Clusters → Create a cluster.

2. Select the cluster Technology type — KVM or LXD.

   Note

   LXD virtualization technology is available only on a cluster with "Switching" or IP-fabric setup type and ZFS file storage. For more information on the technology, see the LXD article.

3. Enter a cluster Name or press generate.
4. Set the Time zone that will be used for cluster nodes and virtual machines (VMs) by default.
5. Enter optional Notes.
6. Click Next.
7. Select the OS that can be installed on virtual machines in the cluster.
8. Enable the option Users can upload their ISO-images to allow VM owners to connect their own ISO images to the VM. Read more in the article Mounting an ISO image.
9. Select the Domains Template for VMs in this cluster. For example, if you specify the template .example.com, when you create a VM in this cluster, it will have a domain of the form vm_name.example.com.
10. Enable the option Users can change a domain name to allow VM owners to change domain names.
11. Enter the RAM overselling rate in the node. Read more in the article Overselling.
12. Specify the VM limit on nodes — the maximum number of VMs that will be created on cluster nodes.
13. Select the type of Distribution of VM on nodes:
    • homogeneous — VMs will be created on the most vacant node of the cluster;
    • successive — VMs will be created on the node of the cluster that is filled up the most. Read more about node selection in Selecting a cluster node for the virtual machine.
14. Click Next.
15. Specify the Storage settings rules on nodes. Read more in the article Storage types:
    1. Images and backups directory. Default value is /image.
       
    2. OS directory. Default value is /share.
       

16. To edit the default storage settings, press .To add a storage, click and specify its settings :
    

     File storage settings

    1. Select Local.
    2. Enter a storage Name.
    3. Select a type — File storage.
    4. Specify the Path for VM directory. Default value is /vm.
    5. Click Save.
     LVM settings

    1. Select Local.
    2. Enter a storage Name.
    3. Select a type — LVM.
    4. Specify the Volume group name. Default value is lvm0.
    5. Click Save.
     Ceph settings

    Read more about Ceph settings in the article Pre-configuration.

    1. Select Network.
    2. Enter a storage Name.
    3. Enter the monitor’s Server IP address in Ceph cluster.
    4. Specify the Port for incoming ssh-connections.
    5. Enter the Root password to connect to the server, or press I want to use public SSH-key to create the ssh-key.
    6. Click Save.
     ZFS settings

    Note

    There can be only one storage in an LXD cluster.

    1. Enter a storage Name.
    2. Specify the ZFS pool name. Default value is zfs0.
    3. Click Save.

    Click main to use the added storage as primary.

    

    Storage configuration interface

17. If a storage for backups is connected to the platform, select it in the Backup location field. For more information about connecting storage, see the article Backup storage.
18. Click Next.

19. Select a Network configuration type:

     Switching

    Switching — a pool is allocated for the cluster, combining blocks of IP addresses from physical networks.

    1. Enable the Second network interface option to create a cluster with the main and additional network interface. This will allow you to create several network cards in the VM. Read more in Main and additional network .

    2. Select IP pools for the virtual machine. If you have enabled the Second network interface option, specify the Pool for the main network and the Pool for the additional network separately.

       Note

       If you plan to use one network for allocating public IP addresses and another for private ones, we recommend using the main network for public IP addresses, and an additional one for private ones.

     Routing

    Routing — a cluster node is assigned subnet of IP addresses. Virtual machines on this node are allocated only the IP addresses from the specified subnet. This subnet routing type does not allow migrating virtual machines to other cluster nodes. Choose this type, if your cluster is located in the data center Hetzner or OVH.

    Note

    If you create a cluster in the data center OVH when preparing the server perform the steps described in the article Server requirements for the cluster.

     IP-fabric

    IP-fabric — a pool is allocated for the cluster, combining blocks of IP addresses from physical networks. Routing between the nodes of the cluster is carried out via the iBGP protocol.

    Note

    Before creating an "IP-fabric" cluster, add the cluster settings to the Route Reflector equipment configuration: IP addresses of nodes and numbers of BGP autonomous systems.

    1. Select IP Pools for VMs in the cluster.

    2. Specify Gateway for IPv4 sessions.

       Note

       VMmanager will assign IP addresses of the gateway to all virtual interfaces on the cluster node and use this data only to route the VM inside the node. You can specify any address that will not conflict with those used in the cluster node.

    3. To configure the IPv4 network, enable the Enable BGP-sessions for IPv4 option and specify the session settings:
       1. Autonomous system BGP number.
       2. BGP community for IPv4.
       3. Neighbor IPv4 address and Autonomous System number for Route Reflector equipment.
       4. Specify an arbitrary Note.
       5. To specify settings for more equipment, click Add more sessions for IPv4.
    4. To configure the IPv6 network, enable the Enable BGP-sessions for IPv6 option and specify the session settings:
       1. Autonomous system BGP number.
       2. BGP community for IPv6.
       3. Neighbor IPv6 address and Autonomous System number for Route Reflector equipment.
       4. Specify an arbitrary Note.

       5. To specify settings for more equipment, click Add more sessions for IPv6.

    
    

    Note

    For an IPv4 network to work in a cluster, add at least one neighbor with an IPv4 address; for an IPv6 network, add at least one neighbor with an IPv6 address.

20. Click on Create.

  Interface of creating a cluster

Connect the nodes to the cluster. For more information please refer to the article Managing servers in the cluster.