Deploying in Existing Red Hat Enterprise Linux Installation

Prerequisites and Guidelines

Before you proceed with deploying the Nexus Dashboard cluster, you must:

  • Review and complete the general prerequisites described in the Deployment Overview.

    The guide is available from the Nexus Dashboard UI or online at Cisco Nexus Dashboard User Guide

  • Review and complete any additional prerequisites described in the Release Notes for the services you plan to deploy.

  • Ensure that your server is running Red Hat Enterprise Linuix (RHEL), Release 8.4.

    This release of Nexus Dashboard support both physical and virtual deployments of RHEL.

  • You can deploy only a single-node or three-node (all master nodes) cluster in RHEL.

    Adding worker or standby node is not supported for this cluster form factor.

  • Clusters deployed in RHEL support only Nexus Dashboard Fabric Controller (NDFC), Release 12.1(1) or later service with SAN Controller deployment type.

    You must deploy one of the other form factors if you want to run any other Nexus Dashboard services or another deployment type of NDFC. For more information about services supported one each Nexus Dashboard cluster form factor, see Cisco Nexus Dashboard Cluster Sizing and Nexus Dashboard and Services Compatibility Matrix.

  • Ensure that the following system-level requirements are satisfied:

    • An existing Linux user on each cluster node, which you will provide to the installer and which can be used to manage and troubleshoot the node.

      Only one system user can connect to the Nexus Dashboard node's system. For more information, see Troubleshooting Nexus Dashboard Deployments in RHEL after the deployment.

    • System clocks across all nodes must be synchronized.

      You can use a system utility such as chrony to ensure proper time synchronization between the nodes.


      Note

      By default, the Nexus Dashboard installer for RHEL verifies that the system clock is synchronized using chrony. If you use a different system to synchronize the clock, you can use ./nd-installer setup input.yaml skip-ntp-check during installation to bypass the default verification.

    • Skopeo package is installed.

      Skopeo is outside the scope of this document, but in short you can use yum install skopeo command to install the package.

    • Swap file is disabled.

      You can disable swap by removing its entry from the /etc/fstab file and restarting the server.

    • The firewalld and libvirt services are stopped and disabled.


    Note

    The following additional system-level changes will be applied when you deploy Nexus Dashboard software to allow executables from additional directories and the cluster's own SSH server: 

    /usr/bin/chcon -R -t bin_t /mnt/atom
/usr/bin/chcon -R -t bin_t /mnt/linux
/usr/bin/chcon -R -t bin_t /opt/apic-sn

/usr/bin/chcon -t ssh_home_t -R /data/services/issh/ssh_host_rsa_key
/usr/bin/chcon -t ssh_home_t -R /data/services/issh/intssh
/usr/sbin/semanage port -a -t ssh_port_t -p tcp 1022

  • Ensure you have enough system resources.

    When deploying in RHEL, you can deploy two types of nodes:

    Table 1. Deployment Requirements

    Nexus Dashboard Version

    Default Node Profile

    Large Node Profile

    Release 2.2.x

    • 16 vCPUs

    • 64 GB of RAM

    • 500GB SSD storage for the data volume and an additional 100GB for the system volume.

      All nodes must be deployed on SSD or faster storage.

    • Two network interfaces in addition to the RHEL's management interface.

    • 32 vCPUs

    • 128 GB of RAM

    • 3TB SSD storage for the data volume and an additional 100GB for the system volume.

      The data volume may be a combination of multiple drives (such as in RAID configuration) as long as the drive is presented as a single device to the operating system.

      All nodes must be deployed on SSD or faster storage.

    • Two network interfaces in addition to the RHEL's management interface.

Deploying Nexus Dashboard in Existing Red Hat Enterprise Linux Installation

This section describes how to configure and bring up a Nexus Dashboard cluster in RHEL.

Before you begin

Procedure

Step 1

Obtain the Cisco Nexus Dashboard software archive package (tarball).

  1. Browse to the Software Download page.

    https://www.cisco.com/c/en/us/support/data-center-analytics/nexus-dashboard/series.html

  2. Click the Downloads tab.

  3. Choose the Nexus Dashboard release version you want to download.

  4. Clik the Download icon next to the Nexus Dashboard tarball (nd-rhel-<version>.tar).

Step 2

Extract the downloaded archive.

tar -xvf nd-rhel-<version>.tar

Step 3

Modify the installation yaml file.

The distribution tarball includes a sample YAML file (./nd-linux/examples/nd-linux-input.yaml), which you can modify to provide the values appropriate to your deployment.

For example, the following sample node configuration YAML file highlights the specific fields which you must provide:

  • For blkdev, provide the SSD devices for the node's image and data volumes.

    You must provide two devices, one for the image and one for the data. The order of the devices in the YAML file does not matter—the smaller disk will be used for image and the larger disk will be used for data.

    Note

     

    Both devices will be erased and consumed for the Nexus Dashboard node.

    For more information on the node device requirements, see Prerequisites and Guidelines.

  • For oobNetwork, provide the management network information:

    • For uplinks, provide the names of the network interfaces which will be used for the cluster's Management and Data networks.

      These interfaces must be dedicated exclusively to the Nexus Dashboard.

    • For ipNet, provide the node's management network IPv4 address and netmask in the 172.23.152.214/24 format.

    • For gatewayIP, provide the node's management network IPv4 gateway.

    • For ipv6Net, provide the node's management network IPv6 address and netmask in the 2001:420:286:2000:6:15:152:220/112 format.

      You can leave this parameter out if you are not configuring dual stack IPv4/IPv6 for your cluster.

    • For gatewayIPv6, provide the node's management network IPv6 gateway.

      You can leave this parameter out if you are not configuring dual stack IPv4/IPv6 for your cluster.

  • For inbandNetwork, you must provide only the interface(s) in the uplinks section as the rest of the configuration is defined during the GUI bootstrap process.

  • For firstMaster, ensure that only one of the node is set to true and the other 2 nodes are set to false.

    You will use the firstMaster node to complete the cluster bootstrap process using the GUI.

  • For clusterName, provide the name of the cluster.

  • For installProfile, choose either Default or Large.

    For more information on the node profile requirements, see Prerequisites and Guidelines.

  • For serviceUser, provide an existing Linux account name which will be used for managing and troubleshooting the Nexus Dashboard node.

    Note

     

    The serviceUser must be different from the system's root user. 

# Node Definition
# 'Master' / 'Worker' / 'Standby'. Only Master supported in 2.2
nodeRole: Master

# Block devices. Can be complete device or partition. Should meet profile requirements.
blkdev:
  - type: SSD
    name: "/dev/sdb"
  - type: SSD
    name: "/dev/sdc"

# Networking
# ND needs exclusively 2 interfaces. Has to be separate from the linux management interface.
oobNetwork:
   uplinks:
  - ens924
  ipNet: 172.23.152.214/24
  gatewayIP: 172.23.152.1
  ipv6Net: 2001:420:286:2000:6:15:152:220/112
  gatewayIPv6: 2001:420:286:2000:6:15:152:1

# Just the interface for the inbandNetwork, rest can be provided at ND bootstrap UI
inbandNetwork:
  uplinks:
  - ens956

# 'true' for one of the masters in a cluster
firstMaster: true

clusterName: nd-cluster

#Installation Profile. Default / Large. Large is used for NDFC SAN installations
installProfile: Default

#Linux username. Cannot be root. Only this user will have privileges to execute certain ND diag commands.
serviceUser: nduser

Step 4

Install Nexus Dashboard node software.

cd nd-linux
./nd-installer setup ./examples/nd-linux-input.yaml

You will be asked to provide the password, which will be used for the Nexus Dashboard cluster admin account.

Note

 

By default, the installer verifies that the system clock is synchronized using chrony. If you use a different system to synchronize the clock, you can use ./nd-installer setup ./examples/nd-linux-input.yamlskip-ntp-check instead to bypass the default verification.

Step 5

Repeat the previous steps to deploy the 2nd and 3rd nodes.

If you are deploying a single-node cluster, you can skip this step.

You do not need to wait for the first node's installation to complete, you can begin deploying the other two nodes simultaneously.

Note

 

When providing the node details in the configuration YAML file for the 2nd and 3rd nodes, ensure that firstMaster parameter is set to false.

Step 6

Wait for all three nodes to finish deploying.

Step 7

Open your browser and navigate to https://<first-node-mgmt-ip> to open the GUI.

The rest of the configuration workflow takes place from one of the node's GUI. You must use the IP address you provided for the node which you designated as firstMaster.

Enter the password you provided in a previous step and click Begin Setup

Step 8

Provide the Cluster Details.

In the Cluster Details screen of the initial setup wizard, provide the following information:

  1. Provide the Cluster Name for this Nexus Dashboard cluster.

  2. Click +Add NTP Host to add one or more NTP servers.

    You must provide an IP address, fully qualified domain name (FQDN) are not supported.

    After you enter the IP address, click the green checkmark icon to save it.

  3. Click +Add DNS Provider to add one or more DNS servers.

    After you enter the IP address, click the green checkmark icon to save it.

  4. Provide a Proxy Server.

    For clusters that do not have direct connectivity to Cisco cloud, we recommend configuring a proxy server to establish the connectivity, which will allow you to mitigate risk from exposure to non-conformant hardware and software in your fabrics.

    If you want to skip proxy configuration, click the information (i) icon next to the field, then click Skip.

  5. (Optional) If your proxy server required authentication, change Authentication required for Proxy to Yes and provide the login credentials.

  6. (Optional) Expand the Advanced Settings category and change the settings if required.

    Under advanced settings, you can configure the following:

    • Provide one or more search domains by clicking +Add DNS Search Domain.

      After you enter the IP address, click the green checkmark icon to save it.

    • Provide custom App Network and Service Network.

      The application overlay network defines the address space used by the application's services running in the Nexus Dashboard. The field is pre-populated with the default 172.17.0.1/16 value.

      The services network is an internal network used by the Nexus Dashboard and its processes. The field is pre-populated with the default 100.80.0.0/16 value.

      Application and Services networks are described in the Prerequisites and Guidelines section earlier in this document.

  7. Click Next to continue.

Step 9

In the Node Details screen, provide the node's information.

  1. Click the Edit button next to the first node.

  2. In the Password field, enter the password for this node and click Validate.

    This will auto-populate the Name, Serial Number, and Management Network information for the node.

    The hostname of the RHEL server where the node software is installed is used for the node's Name.

  3. Provide the node's Data Network information.

    The Management Network information is already pre-populated with the information you provided for the first node.

    You must provide the data network IP address/netmask (for example, 172.31.140.58/24) and gateway (for example, 172.31.140.1). Optionally, you can also provide the VLAN ID for the network. For most deployments, you can leave the VLAN ID field blank.

  4. (Optional) Provide IPv6 addresses for the management and data networks.

    Nexus Dashboard supports either IPv4 or dual stack IPv4/IPv6 for the management and data networks.

    Note

     

    If you want to provide IPv6 information, you must do that now during cluster bootstrap process. If you deploy the cluster using only IPv4 stack and want to add IPv6 information later, you would need to redeploy the cluster.

    All nodes in the cluster must be configured with either only IPv4 or dual IPv4/IPv6 stack.

  5. (Optional) If required, Enable BGP for the data network.

    BGP configuration is required for the Persistent IPs feature required by some services, such as Nexus Dashboard Insights with NDFC fabrics. This feature is described in detail in the "Persistent IP Addresses" sections of the Nexus Dashboard User's Guide.

    Note

     

    You can enable BGP at this time or in the Nexus Dashboard GUI after the cluster is deployed.

    When you enable BGP, you must also provide the following information:

    • ASN (BGP Autonomous System Number) of this node.

      You can configure the same ASN for all nodes or a different ASN per node.

    • BGP Peer Details, which includes the peer's IPv4 or IPv6 address and peer's ASN.

  6. Click Save to save the changes.

Step 10

In the Node Details screen, click Add Node to add the second node to the cluster.

The Node Details window opens.

  1. In the Deployment Details section, provide the node's Management IP Address and Password, then click Verify.

    This is the password you provided to the ./nd-installer setup command during installation in Step 4.

    Verifying the IP and password will auto-populate the Name, Serial Number, and Management Network information for the node.

    The hostname of the RHEL server where the node software is installed is used for the node's Name.

  2. Provide the node's Name.

  3. Provide the node's Data Network IP address and gateway.

    The Management Network information will be pre-populated with the information pulled from the node based on the management IP address and credentials you provided in the previous sub-step.

    You must provide the data network IP address/netmask (for example, 172.31.141.58/24) and gateway (for example, 172.31.141.1). Optionally, you can also provide the VLAN ID for the network. For most deployments, you can leave the VLAN ID field blank.

  4. (Optional) Provide IPv6 information for the management and data networks.

    Nexus Dashboard supports either IPv4 or dual stack IPv4/IPv6 for the management and data networks.

    Note

     

    If you want to provide IPv6 information, you must do it during cluster bootstrap process. If you deploy the cluster using only IPv4 stack and want to add IPv6 information later, you would need to redeploy the cluster.

    All nodes in the cluster must be configured with either only IPv4 or dual IPv4/IPv6 stack.

  5. (Optional) If required, Enable BGP for the data network.

  6. Click Save to save the changes.

Step 11

Repeat the previous step to add the 3rd node.

Step 12

In the Node Details screen, click Next to continue.

After you've provided the information for all 3 nodes in the cluster, continue to the next screen of the bootstrap process.

Step 13

In the Confirmation screen, review and verify the configuration information and click Configure to create the cluster.

During the node bootstrap and cluster bring-up, the overall progress as well as each node's individual progress will be displayed in the UI. If you do not see the bootstrap progress advance, manually refresh the page in your browser to update the status.

It may take up to 30 minutes for the cluster to form and all the services to start. When cluster configuration is complete, the page will reload to the Nexus Dashboard GUI.

Step 14

Verify that the cluster is healthy.

It may take up to 30 minutes for the cluster to form and all the services to start.

After all three nodes are ready, you can log in to any one node via SSH using the serviceUser you provided in the configuration YAML and run the following command to verify cluster health:

  1. After logging in to the Linux system, connect to the node using the /usr/bin/attach-nd command.

    This command can be used only by the serviceUser user.

  2. Verify that the cluster is up and running.

    You can check the current status of cluster deployment by logging in to any of the nodes and running the acs health command.

    While the cluster is converging, you may see the following outputs:

    $ acs health
k8s install is in-progress
    $ acs health
k8s services not in desired state - [...]
    $ acs health
k8s: Etcd cluster is not ready
    When the cluster is up and running, the following output will be displayed:
    $ acs health
All components are healthy

  3. Log in to the Nexus Dashboard GUI.

    After the cluster becomes available, you can access it by browsing to any one of your nodes' management IP addresses. The default password for the admin user is the same as the password you provided to the ./nd-installer setup command during installation in Step 4.

Uninstalling Nexus Dashboard Software

When the Nexus Dashboard node software is deployed, the uninstaller is copied into the /usr/bin directory.

If at any point you want to uninstall the software, simply run the following command as the root user: 

/usr/bin/nd-installer uninstall

Note

If you log in to the RHEL system using SSH, you must connect to the system's management IP address to uninstall; you must not use the Nexus Dashboard's management IP addresses.

This will remove the software and undo the file system changes done during the installation process.

Troubleshooting Nexus Dashboard Deployments in RHEL

This section describes common troubleshooting steps for Nexus Dashboard software deployed in RHEL.

Procedure

Step 1

Check installation logs.

Nexus Dashboard installation logs are available in the following directory:

/logs/ndlinux/

Step 2

Access the Nexus Dashboard environment after installation.

  1. Log in to your RHEL system using the Nexus Dashboard user you provided in the YAML configuration file during installation.

  2. Access the Nexus Dashboard environment.

    /usr/bin/attach-nd

  3. Use the common Nexus Dashboard troubleshooting commands.

    After you access the Nexus Dashboard environment, you can use all the common Nexus Dashboard commands described in the "Troubleshooting" section of the Cisco Nexus Dashboard User Guide.