Adding hosts

The IBM® Cloud Infrastructure Center installation is first on the management node and adds the compute node (namely host) later. When the management node is installed correctly, you can log on to the IBM® Cloud Infrastructure Center with your username and password. As the UI shows, select Add Host on the Hosts page to add a host. However, before you add host, it is necessary to complete some requirements.

Note: The IBM Cloud Infrastructure Center supports z/VM® and KVM host management type.

Follow these steps to finish adding host:

  1. On the Hosts page, select Add Host. A window opens where you need to select the host management type (z/VM or KVM) and type the information of host that you expect to add.

    1) The item information in the following table is common for z/VM and KVM.

    Name Required Type Description
    Hostname or IP address Yes Common Type the hostname or IP address of the host you want to add, in which the hostname needs to be resolved by IBM Cloud Infrastructure Center (You might check hostname by referring to Verify settings for the network.

    Note: You need check whether the hostname or IP address of the host can be connected from the management node. You can ping <hostname> or ping <host ip address> to check it.

    Display name No Common It is a unique name that is displayed in the IBM Cloud Infrastructure Center to identify the respective host. If you type nothing into this item, the host's static hostname is displayed in the IBM® Cloud Infrastructure Center instead.

    Note: This name can include only letters, numbers, dashes(-), and underscores(_).

    User ID Yes Common Type the Linux user of the host. Both root user and non-root user are supported. Add host with root/non-root user reference link to User setting for add Host with root or non-root
    Authentication type Yes Common The IBM® Cloud Infrastructure Center supports two types of authentication:
    • Password: Select Password and specify the password for the user ID.
    • SSH key: Select SSH key and then upload the ssh key that is generated in advance to access to the host.

    Note: As for non-root user ID, it needs to be created and granted with root authority in advance.

    Password Yes Common It is the password of the linux user input in User ID item.
    SSH key Yes Common It is the ssh private key file that is generated in advance for the User ID to access to the host.

    2) z/VM

    Note for z/VM® host management

    Fill the following fields to finish adding a host for z/VM:

    Name Required Type Description
    Vswitch Name Yes z/VM only The name of vswitch on the compute node you plan to use.

    Note: the colon character (:) is not allowed.

    FCP vHBA Devices No z/VM only FCP vHBA devices are also called FCP devices. This value is necessary only if you want to use persistent storage as the root or data disks for the virtual machines on z/VM hosts (Refer to Boot From Volume and Attach volumes to virtual machines).
    Disk Pool No z/VM only This value is required to create root or data disks from the z/VM® dasd group for the virtual machines. It has 2 parts that are separated by a colon(:). The first part is the type of disks in the dasd group. The disks in one dasd group must be in the same type (ECKD or FBA). Possible values of the dasd group type are either ECKD or FBA. The second part is the volume group name defined in your directory manager on your z/VM® system that is used for allocating disks for new virtual machines. Sample Disk pool values: ECKD:diskpo1 or FBA:testpool.

    Notes:

    • A dollar sign ($) is not allowed in the volume group name.
    • The Disk Pool must be consistency of the upper/lower case for all hosts that are managed by same management node.
    • If you do not input Disk Pool here, you can edit Disk pool later with the Edit Host Connection button in the Hosts pane. Refer to Edit host.
    • If the dasd group is used up, contact the z/VM® administrator to increase the dasd group size at z/VM® level, and the IBM® Cloud Infrastructure Center can automatically use the added disks.
    • Once the host is added, on the Overview page of the host, you can get the dasd group consumption from the section of Dasd Group Details. Free Size (GB) is the available disk space for each dasd device of the dasd group.

    3) KVM

    Note for KVM host management

    Fill the following fields to finish adding a host for KVM:

    Name Required Type Description
    Network interface name Yes KVM only Enter a network interface on the host that can be assigned to Open vSwitch bridge, for example eth0. This interface is used to provide connectivity for KVM guests.

    Notes:

    • When the network interface is used, the original assigned IP to this interface is not accessible anymore.
    • The input network interface can be an interface connecting to a single OSA or HiperSockets card, a bonded interface, or a team interface. For more information about these 2 types of interfaces, refer to Terminology
    • When you add multiple KVM hosts (one host is one LPAR) and if the Network interfaces name you input for different KVM hosts are associated to the same OSA or HiperSockets adapter, then, only the 1st host can be added, successfully. The others might fail due to missing to set the Bridgeport mode for this OSA or HiperSockets adapter (the 1st host already set). This happens when an OSA or HiperSockets adapter is shared across multiple LPARs on the same system. Only a single LPAR can be configured for the Bridgeport mode at any point in time. So, separate KVM hosts for the Bridgeport mode concurrently require separate OSA or HiperSockets adapters. You can also use VNICC functionality of the OSA or HiperSockets in the supported model that does not have this limitation.
    • For more information, refer to: Planning for KVM networks and Hardware and software requirements for KVM system.
    Shared storage path No KVM only It's a local path on the host that mounts to a remote share storage (such as IBM Storage Scale/NFS storage). If you do not enter anything to this item, the local storage on the host is used for the virtual machines as root and data disks. Refer to Planning share storage for more details.

    Notes:

    • It is not supported to change Shared storage path once the host is managed.
    • Make sure the IBM Storage Scale/NFS storage server is always active, or else the host fails to be added for timeout exception and the virtual machine deployment might fail for permission denial.
    • Make sure the Shared storage path is always mounted to the share storage server, or else the local storage of the host is used and the virtual machine deployment may fail for permission denial.
    • Make sure the selinux context type of the Shared_storage_path is nfs_t. You can use ls -alZ to check it. If it's not nfs_t, you can use chcon -t nfs_t Shared_storage_path to update it.
    Secure Execution No KVM only Select it to enable IBM SE(Secure Execution) capability for Linux in the host to deploy IBM SE guest. Refer to Planning for secure execution for more details.

    Notes:

    • Only when the host enables the IBM SE feature for Linux and the Secure Execution is selected here, the host can be managed as one real SE host by the IBM® Cloud Infrastructure Center and you can deploy both of IBM SE guest and non-SE guest on it.
    • If the host enables the IBM SE feature for Linux and the Secure Execution is not selected here, the host is managed as one non-SE host by the IBM Cloud Infrastructure Center, and you can only deploy non-SE guest on it. For such a host, you can also select Secure Execution later to manage the host as one IBM SE host that uses the Edit Host button in the Hosts pane. Refer to Edit host.
    • If the host does not enable the IBM SE feature for Linux and the Secure Execution is selected here, adding host fails for The secure execution is not enabled on the host ***. Ensure it is enabled if you want to use this capability.
    • If the host does not enable the IBM SE feature for Linux and the Secure Execution is not selected here, the host is managed as one non-SE host by the IBM Cloud Infrastructure Center, and you can only deploy non-SE guest on it.
    OVN Encapsulation IP No KVM only It is the overlay network(Geneve network) local endpoint IP address on the KVM Host. For more information, refer to OVN Encapsulation IP.

    Notes:

    • The OVN Encapsulation IP is not managed by the IBM Cloud Infrastructure Center. You need to maintain the lifecycle of this IP.
    • If an empty value is input, the IBM Cloud Infrastructure Center uses the IP in the KVM hostname or IP address input box as the overlay network local endpoint IP address.
    • The OVN Encapsulation IP allows to be edited when editing host.
  2. Click Add Host, the add host process begins. If the host is added for the first time, the authenticity of host cannot be verified and click Connect to continue. After Add Host is submitted, another dialog with Add another or Dismiss window is shown.

    • Only one management node can manage the host at a given time. If the host to be added has already been managed by the IBM Cloud Infrastructure Center, the host needs to be removed from the other management node first.

    • If the authentication type is SSH key, more detailed steps are at: add host with SSH key.

    • z/VM only The host can be used to do both, deploy the new virtual machines and manage the existing virtual machines.

    • KVM only The UI shows a warning information "Existing access key files for user 'username' on compute node 'hostname' may lead to live migration failure." If the existing key file 'id_rsa' or 'id_rsa.pub' in the folder '/root/.ssh/' on the host added from the UI. To avoid this problem, remove the key files 'id_rsa' and 'id_rsa.pub' under '/root/.ssh/' before adding the host. 'hostname': is the hostname added to the management node. 'username': Username to manage the compute node by the IBM® Cloud Infrastructure Center.

    • KVM only The migration may not work without any notification if the key files 'id_rsa', 'id_rsa.pub' or 'authorized_keys' are changed during the compute node's management.

    • KVM only If the shared storage of the IBM® Storage Scale or NFS is used for migration, complete the configuration of the share storage mount point before adding the host operation and fill the mounted path on the UI. And ensure the shared storage server of the IBM® Storage Scale or NFS be available.

  3. Adding a host might take a few minutes. If the host is discovered and added into IBM Cloud Infrastructure Center successfully, the UI message "PD-A000318 The host xxx was added to IBM Cloud Infrastructure Center successfully." is shown on the Messages page, and the host's information is shown on the Hosts page, which includes the host's display name, processors, memory, the number of virtual machines on the host, the host health status, the Secure Execution capability of the host and the host connection item.

  4. After the host is added as compute node, one new config file nova-<nodename>.conf is created under /etc/nova on the management node.

    • As for z/VM, the node name is the hypervisor hostname of the host.

    • As for KVM, the node name is the hypervisor FQDN(Fully Qualified Domain Name) hostname of the host.

Notes:

  • When the host is added to the IBM Cloud Infrastructure Center, it is not allowed to change its hostname (you might use hostname command to check it). Otherwise, there would be some unexpected results, such as instances deploy and management failed. If the message "Existing access key files for user root on compute node hostname may lead to live migration not work." is shown on the UI. The migration operation fails.

  • For host management of multi-node cluster, refer to Note for host management of multi-node cluster