Cisco Nexus Dashboard Troubleshooting, Release 3.0.x

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Last updated: April 6, 2024
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Useful Commands

You can log in to any of the cluster nodes as rescue-user for a limited access to system data. You can use the following commands to perform various operations in Cisco Nexus Dashboard.

Cluster Troubleshooting:

  • acs health — displays cluster health information and any existing issues.

  • acs show cluster — displays cluster configuration.

  • acs show nodes — displays information about all nodes in the cluster.

  • acs show masters — displays information about primary nodes in the cluster.

  • acs show workers — displays information about worker nodes in the cluster.

  • acs show standbys — displays information about standby nodes in the cluster.

  • acs ntp show — displays NTP information.

  • acs techsupport collect -s system — collects Infra tech support information.

  • acs techsupport collect -s cisco-mso — collects Nexus Dashboard Orchestrator service tech support information.

  • acs techsupport collect -s cisco-nir — collects Nexus Dashboard Insights service tech support information.

  • acs techsupport collect -s cisco-appcenter — collects App Store tech support information.

  • acs version — returns the Nexus Dashboard version.

Resetting Devices:

  • acs reboot — reboots the node with all services and configurations intact.

  • acs reboot clean — removes all data for Nexus Dashboard and applications, but preserves the Nexus Dashboard bootstrap configuration and pod images.

    Clean reboot must be done on all notes simulataneously; if you clean reboot a single node while the other 2 primary nodes remain, the rebooted node will come up and recover from the existing cluster.

    When you first bring up your Nexus Dashboard cluster, initial deployment process installs all required pod images. Retaining pod images will speed up cluster bring up after reboot.

    If you plan to re-install all the nodes in the cluster, you must clean up the site and app information first. In this case, ensure that the sites are disabled in all applications and removed from the ND cluster.

  • acs reboot clean-wipe — removes all data for Nexus Dashboard and applications including application images, but preserves the Nexus Dashboard bootstrap configuration.

    When the cluster boots up again, pod images will be re-installed.

    If you plan to re-install all the nodes in the cluster, you must clean up the site and app information first. In this case, ensure that the sites are disabled in all applications and removed from the ND cluster.

  • acs reboot factory-reset — removes all data for Nexus Dashboard and applications including cluster bootstrap configuration, but preserves application images.

    When you first bring up your Nexus Dashboard cluster, initial deployment process installs all required pod images. Retaining pod images will speed up cluster bring up.

    If you plan to re-install all the nodes in the cluster, you must clean up the site and app information first. In this case, ensure that the sites are disabled in all applications and removed from the ND cluster.

  • acs reboot factory-wipe — removes all data for Nexus Dashboard and applications, including application images and cluster bootstrap configuration.

    When the cluster boots up again, the pod images will be re-installed.

    If you plan to re-install all the nodes in the cluster, you must clean up the site and app information first. In this case, ensure that the sites are disabled in all applications and removed from the ND cluster.

System and Connectivity Troubleshooting:

  • The /logs directory is mounted into the rescue-user container and can be inspected with standard tools.

  • ping command is supported with most options.

  • ip command supports a read-only subset of commands, including ip addr show and ip route show.

  • kubectl command supports read-only Kubernetes commands.

    For example, you can use it to get a list of all pods running in the system:

    $ kubectl get pods -A
NAMESPACE         NAME                           READY   STATUS   RESTARTS     AGE
aaamgr            aaamgr-54494fdbc8-q8rc4        2/2     Running  0            3d3h
authy-oidc        authy-oidc-75fdf44b57-x48xr    1/1     Running  3 (3d3h ago) 3d4h
authy             authy-857fbb7fdc-7cwgg         3/3     Running  0            3d4h
cisco-appcenter   apiserver-686655896d-kmqhq     1/1     Running  0            3d3h
[...]

  • acs elasticsearch command invokes a custom utility that allows you to get debug information about the services.

    $ acs elasticsearch --name cisco-ndfc-controller-elasticsearch health
{
  "cluster_name" : "cisco-ndfc-controller-elasticsearch",
  "status" : "green",
  "timed_out" : false,
  "number_of_nodes" : 3,
  "number_of_data_nodes" : 3,
  "discovered_master" : true,
  "active_primary_shards" : 10,
  "active_shards" : 21,
  "relocating_shards" : 0,
  "initializing_shards" : 0,
  "unassigned_shards" : 0,
  "delayed_unassigned_shards" : 0,
  "number_of_pending_tasks" : 0,
  "number_of_in_flight_fetch" : 0,
  "task_max_waiting_in_queue_millis" : 0,
  "active_shards_percent_as_number" : 100.0
}

    You can obtain the list of the service-specific pod names using the kubectl command, for example:

    $ kubectl get pods -A | grep elasticsearch
cisco-ndfc-controller-elasticsearch   es-data-0   2/2     Running     0   109m
cisco-ndfc-controller-elasticsearch   es-data-1   2/2     Running     0   163m
cisco-ndfc-controller-elasticsearch   es-data-2   2/2     Running     0   104m
Application Information:

  • acs apps instances command displays all applications running on the cluster.

  • acs apps actions command displays the history operations done on the applications, such as installations, upgrades, or deletions.

Upgrading CIMC

When you upgrade Nexus Dashboard software, you may also have to upgrade the version of Cisco Integrated Management Controller (CIMC) that is running in your Nexus Dashboard nodes.

Supported CIMC versions for each Nexus Dashboard release are listed in the Release Notes specific to that release.

The following steps describe how to upgrade the Nexus Dashboard CIMC using the Cisco Host Upgrade Utility (HUU). Additional details about the Host Upgrade Utility are available at Upgrading the Firmware on a Cisco UCS C-Series Server Using the HUU.

Before You Begin

  • Check the Release Notes for your Nexus Dashboard release to confirm the CIMC versions supported by that release.

  • Allow for the appropriate amount of time for the upgrade.

    The time required for the upgrade process depends on a number of factors, such as the speed of the link between the local machine and the UCS-C chassis, the source and target software images, as well as other internal component versions.

  • If you’re upgrading a single node that is running an older firmware to add it to an existing cluster, you will perform the following steps on that node only and not on all nodes in the cluster.

  • Updating CIMC may also require updating your browser and/or Java software version to run the vKVM used to upgrade the CIMC.

note.svg

Upgrading the CIMC version does not affect your production network as the Nexus Dashboard nodes are not in the data path of the traffic.

To upgrade the Nexus Dashboard CIMC software:

  1. Open your browser, navigate to the CIMC IP address, and log in using the CIMC credentials.

    Note that the CIMC credentials may be different from the Nexus Dashboard GUI credentials.

  2. Determine the model of UCS platform for your Nexus Dashboard by locating the first part of the BIOS version under Server > Summary .

    Nexus Dashboard supports the UCS-C220-M5 and UCS-C225-M6 servers.

    cimc-server-summary.jpg

  3. If necessary, clear the existing logs.

    cimc-clear-logs.jpg

    1. Click the hamburger menu to show the available options.

    2. Choose Faults and Logs.

    3. In the main pane, choose the System Event Log tab and wait for the logs to load.

    4. If the log is full, click Clear Log.

  4. Download the appropriate HUU ISO image.

    cimc-download-huu.jpg

    1. Navigate to the software download page for your server model.

      For UCS-C220-M5, browse to https://software.cisco.com/download/home/286318809/type/283850974.

      For UCS-C225-M6, browse to https://software.cisco.com/download/home/286329390/type/283850974.

    2. In the left sidebar, select the version supported by your target Nexus Dashboard release.

      The list of supported releases is available in the Release Notes.

    3. In the main pane, click on the Download icon.

    4. Click Accept License Agreement.

  5. Launch the KVM console from CIMC GUI.

    note.svg

    If you are unable to open the KVM console, you may need to update Java version.

    cimc-launch-kvm.jpg

  6. Mount the HUU ISO image you downloaded in Step 3.

    1. From KVM console’s Virtual Media menu, choose Activate Virtual Devices.

      This adds virtual media options under the Virtual Media menu.

    2. From KVM console’s Virtual Media menu, choose Map CD/DVD.

    3. In the Virtual Media - CD/DVD dialog that opens, click Browse and choose the HUU image.

      cimc-map-iso.jpg

    4. Finally, click Map Drive.

  7. From KVM console’s Power menu, choose Power Cycle System to reboot the server.

  8. As the server is starting up, press F6 to enter the boot menu and choose the Cisco vKVM-Mapped vDVD.

    cimc-select-boot-device.jpg

  9. When prompted to accept Cisco Software License Agreement, choose Accept.

    cimc-accept-license.jpg

  10. In the Update & Activate All dialog, choose Update & Activate.

    cimc-update-activate.jpg

    You can verify that the upgrade was completed successfully through the GUI or by booting up the CIMC HUU and selecting the Last Update Verify option to ensure that all of the components were upgraded successfully.

  11. After upgrade is completed, ensure that Trusted Platform Module State (TPM) is enabled.

    You can check and enable it in the BIOS > Configure BIOS > Security menu.

Manual Cluster Upgrades

We recommend using the procedure described in Firmware Management#_firmware_management_cluster_upgrades section to upgrade your cluster.

However, if you want to perform a manual upgrade of a single node (if you’re adding a new node to the cluster but the node is running older firmware) or entire cluster (in case the GUI upgrade did not succeed), you can use the following steps instead.

note.svg

If you’re upgrading a single node that is running an older firmware to add it to an existing cluster, you will perform the following steps on that node only and not on the entire cluster.

  1. Log in to the nodes you want to upgrade as rescue-user.

  2. Copy the upgrade ISO image file into the /tmp directory on each node.

  3. Start the upgrade on all nodes.

    You can upgrade all nodes in parallel.

    # acs installer update -f /tmp/nd-dk9.3.0.1a.iso
Warning: This command will initiate node update to new version.
Proceed? (y/n): y
Update in Progress ... Do not press Ctrl^C

  4. Wait for the upgrade to complete.

    note.svg

    You must wait for all nodes to finish upgrading before proceeding to the next step.

    Update succeeded, reboot your host

  5. Reboot one of the nodes.

    Ensure that the upgrade is completed on all nodes as mentioned in the previous step before restarting any one node.

    # acs reboot
This command will restart this device, Proceed? (y/n): y

  6. Verify that the upgrade was successful.

    # acs health --upgrade
All components are healthy

  7. After the first node is successfully upgraded and healthy, reboot the other two nodes one at a time.

    note.svg

    You must wait for the rebooted node to come up and ensure that the node is healthy using the acs health --upgrade command before restarting the next node.

  8. Once all nodes are up running the new version and are healthy, run post-upgrade tasks.

    You can run the following command on all nodes in parallel.

    # acs installer post-update
Warning: This command will run the post-update scripts. Proceed? (y/n): y
Update in Progress ... Do not press Ctrl^C
Post-update succeeded
    note.svg

    If the command fails, wait an additional 10 minutes and retry.

  9. Wait for the post-upgrade tasks to complete.

    During this stage if you attempt to log in to the node, the UI will show the progress, which looks similar to the initial cluster deplyment. After the post-upgrade processes finish, you will be able to log in to the node as usual.

  10. Verify that all nodes and the cluster are healthy.

    # acs health
All components are healthy

Re-Imaging Nodes

When you first receive the Nexus Dashboard physical hardware, it comes preloaded with the software image. If you simply want to configure the existing software, skip this section and proceed to Managing Worker Nodes. or Managing Standby Nodes..

If you are looking to manually upgrade the node to the latest software version, follow the instructions in [Manual Upgrades] instead.

This section describes how to redeploy the software stack on the Nexus Dashboard hardware. You may need to use the following steps in case of a catastrophic failure where you are no longer able to access the server’s operating system and GUI, or in case you want to deploy a different release that does not support direct upgrade or downgrade from your existing cluster.

note.svg

If you are planning to re-install an existing Nexus Dashboard cluster, you must clean up the site and app information first. In this case, ensure that the sites are disabled in all applications and removed from the ND cluster before bringing it down.

Before You Begin

Installing Nexus Dashboard Using Remotely-Hosted Image

To re-install the Nexus Dashboard software:

  1. Download the Cisco Nexus Dashboard image.

    1. Browse to the Nexus Dashboard page and download the image.

      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 version you want to download.

    4. Download the Cisco Nexus Dashboard image (nd-dk9.<version>.iso).

    5. Host the image in a web server in your enviornment

      You will need to provide an http URL when mounting the image.

  2. Deploy the ISO to the server.

    This step requires you to connect to the server’s CIMC. Detailed information about CIMC configuration is available at https://www.cisco.com/c/en/us/support/servers-unified-computing/ucs-c-series-integrated-management-controller/products-installation-and-configuration-guides-list.html.

    1. SSH into the server’s CIMC.

    2. Connect to the virtual media.

      C220-WZP21510DHS# scope vmedia
C220-WZP21510DHS /vmedia #

    3. Map the Nexus Dashboard image you downloaded to the CIMC-Mapped vDVD.

      C220-WZP21510DHS /vmedia # map-www image http://<ip-address>/<path> <image>

      For example:

      C220-WZP21510DHS /vmedia # map-www image http://172.31.131.47/images nd-dk9.2.0.1.iso

    4. Verify that the image is mounted.

      C220-WZP21510DHS /vmedia # show mappings
Volume  Map-Status  Drive-Type  Remote-Share   Remote-File       Mount-Type
------- ----------- ----------- -------------- ----------------- --------
image   OK          CD          [<ip>/<path>]  nd-dk9.2.0.1.iso  www

    5. Reboot the server and connect to its console.

      C220-WZP23150D4C /vmedia # exit
C220-WZP23150D4C# scope chassis
C220-WZP23150D4C /chassis # power cycle
C220-WZP23150D4C /chassis # exit
C220-WZP23150D4C# connect host
CISCO Serial Over LAN:
Press Ctrl+x to Exit the session

    6. Select the boot device.

      Watch the boot process until you see the following message:

      Press <F2> Setup, <F6> Boot Menu, <F7> Diagnostics, <F8> Cisco IMC Configuration, <F12> Network Boot

      Then press F6 and select the virtual media device where you mounted the image (Cisco CIMC-Mapped vDVD1):

      /------------------------------------\
| Please select boot device: |
|------------------------------------|
| (Bus 05 Dev 00)PCI RAID Adapter |
| UNIGEN PHF16H0CM1-DTE PMAP |
| Cisco vKVM-Mapped vHDD1.22 |
| Cisco CIMC-Mapped vHDD1.22 |
| Cisco vKVM-Mapped vDVD1.22 |
| Cisco CIMC-Mapped vDVD1.22 |
| Cisco vKVM-Mapped vFDD1.22 |
| UEFI: Built-in EFI Shell |
| IBA GE Slot 0100 v1585 |
| IBA GE Slot 0101 v1585 |
| Enter Setup |
|------------------------------------|
| ^ and v to move selection |
| ENTER to select boot device |
| ESC to boot using defaults |
\------------------------------------/

    7. Configure the networking.

      When the server first boots, you will see the following output:

      + '[' -z http://172.31.131.47/nd-dk9.2.0.1.iso ']'
++ awk -F '/|:' '{print $4}'
+ urlip=172.31.131.47
+ '[' -z 172.31.131.47 ']'
+ break
+ '[' -n http://172.31.131.47/nd-dk9.2.0.1.iso ']'
+ set +e
+ configured=0
+ '[' 0 -eq 0 ']'
+ echo 'Configuring network interface'
Configuring network interface
+ echo 'type static, dhcp, bash for a shell to configure networking, or url to re-enter the url: '
type static, dhcp, bash for a shell to configure networking, or url to re-enter the url:
+ read -p '? ' ntype
? static (1)
+ case $ntype in
+ configure_static
+ echo 'Available interfaces'
Available interfaces
+ ls -l /sys/class/net
total 0
lrwxrwxrwx. 1 root root 0 Apr 26 01:21 enp1s0f0 -> ../../devices/pci0000:3a/0000:3a:00.0/0000:3b:00.0/net/enp1s0f0
lrwxrwxrwx. 1 root root 0 Apr 26 01:21 enp1s0f1 -> ../../devices/pci0000:3a/0000:3a:00.0/0000:3b:00.1/net/enp1s0f1
lrwxrwxrwx. 1 root root 0 Apr 26 01:21 enp1s0f4 -> ../../devices/pci0000:5d/0000:5d:00.0/0000:5e:00.0/0000:5f:01.0/0000:61:00.0/0000:62:00.0/0000:63:00.0/net/enp1s0f4
lrwxrwxrwx. 1 root root 0 Apr 26 01:21 enp1s0f5 -> ../../devices/pci0000:5d/0000:5d:00.0/0000:5e:00.0/0000:5f:01.0/0000:61:00.0/0000:62:00.0/0000:63:00.1/net/enp1s0f5
lrwxrwxrwx. 1 root root 0 Apr 26 01:21 lo -> ../../devices/virtual/net/lo
+ read -p 'Interface to configure: ' interface
Interface to configure: enp1s0f0  (2)
+ read -p 'address: ' addr
address: 172.23.53.59/21  (3)
+ read -p 'gateway: ' gw
gateway: 172.23.48.1  (4)
+ ip addr add 172.23.53.59/23 dev enp1s0f0
+ ip link set enp1s0f0 up
+ ip route add default via 172.23.48.1
RTNETLINK answers: Network is unreachable
++ seq 1 2
+ for count in '$(seq 1 2)'
+ ping -c 1 172.31.131.47
      1 For IP address, enter dchp if there is a DHCP server in your environment or static.
      2 For the interface, enter the first management port (enp1s0f0).
      3 If you chose static, provide the IP address for the connection.
      4 If you chose static, provide the gateway for the connection.

  3. After the server boots from the provided image, select the only available installation option.

    It may take up to 20 minutes for the installation process to complete.

    After the image is deployed, you can add the node to your cluster as described in Managing Worker Nodes. or Managing Standby Nodes..

Rebuilding Existing Cluster

In some cases, you may need to re-build an existing cluster, for example if you want to change the data network’s subnet or the nodes' data IP addresses, which requires redeploying the cluster.

  1. Back up the Nexus Dashboard cluster configuration as described in [Backup and Restore].

  2. Back up the configuration for all services deployed in your cluster.

    For NDO, see Operations > Backup and Restore in the Nexus Dashboard Orchestrator Configuration Guide.

    For NDI, see Operations > Backup and Restore in the Nexus Dashboard Insights User Guide.

    For NDFC, see Operations > Backup and Restore in the NDFC Fabric Controller Configuration Guide.

  3. If your cluster is deployed as a physical appliance…​

    1. Log in to each node as rescue-user.

    2. On each node, run the acs reboot factory-reset.

      This resets the node to factory settings and reboots it.

    3. Redeploy the cluster using the same hardware.

      You can follow the same procedure as you did when you first deployed the cluster, which is described in the "Deploying as Physical Appliance" chapter of the Nexus Dashboard Deployment Guide

  4. If your cluster is deployed in virtual machines (VMs)…​

    1. Power down existing VMs.

      You can keep the existing cluster’s VMs until you deploy a new cluster and restore services and their configuration in it. Then you can simply delete the old cluster’s VMs.

    2. Redeploy a brand new cluster.

      You can follow the same procedure as you did when you first deployed the cluster, which is described in the "Deploying in VMware ESX" or "Deploying in Linux KVM" chapter of the Nexus Dashboard Deployment Guide

  5. Restore Nexus Dashboard configuration as described in [Backups and Restore].

  6. Install the service(s) you had deployed previously as described [Service Management].

  7. Restore each service’s configuration from the backups you created in Step 1.

    For NDO, see Operations > Backup and Restore in the Nexus Dashboard Orchestrator Configuration Guide.

    For NDI, see Operations > Backup and Restore in the Nexus Dashboard Insights User Guide.

    For NDFC, see Operations > Backup and Restore in the NDFC Fabric Controller Configuration Guide.

Zookeeper/Kafka Service Recovery

AppStore Errors

When attempting to access the Services > AppStore tab in the Nexus Dashboard GUI, you may encounter the following error:

{
  "error": "There was a problem proxying the request"
}
Cause

When a primary node where the AppStore service is running fails, it may take up to 5 minutes for the AppStore services to relocate to another primary node

Resolution

Simply wait for the services to recover and refresh the page.

Event Export

Syslog events are not reaching the intended external events monitoring service.

Cause

Most common cause of this issue is not configured or improperly configured Syslog destination server.

Resolution

Ensure that the external server configuration in Cluster Configuration > Syslog is correct. For more information, see [Cluster Configuration].

Cause 2

Remote server is allowing traffic from only a specific set of IP addresses and the traffic from the Nexus Dashboard nodes' IP addresses is not allowed.

Resolution 2

Update your external server’s configuration to allow traffic from the Nexus Dashboard cluster nodes.

Factory Reset

You can reset the entire physical cluster by running the following command on each node:

# acs reboot factory-reset
note.svg

Doing this will lose all cluster configuration and applications and you will need to rebuild the cluster.

If you have a virtual or cloud Nexus Dashboard cluster, we recommend simply deleting the existing VMs and re-deploying the entire cluster instead of reseting all the nodes, as described in the Cisco Nexus Dashboard Deployment Guide.

Changing Node IP Addresses

Changing the data network IP address is not supported. If you want to change the data IP address for the cluster nodes, you must re-create the cluster.

If you are running a single-node cluster, changing the management IP address is also not supported without re-creating the cluster.

If you are running a multi-node cluster, you can change the management IP addresses of one or more nodes as follows:

  1. Navigate to your Nexus Dashboard’s Admin Console.

  2. From the main navigation menu, select System Resources > Nodes.

  3. From the (…​) menu next to the node, choose Edit Node.

    Note that you can only change the IP address of a node that you are not currently logged in to. To change the IP of the current node, navigate to a different node’s management IP address, log in, and repeat this procedure for the last node.

  4. Update the Management Network Address and Management Network Gateway for the node.

    For example, 172.31.140.58/24 and 172.31.140.1 respectively.

  5. Click Save.

    The changes will take effect immediately and you can access the nodes using the new IP addresses.

Cluster Configuration Errors

When you configure or change the proxy server in Nexus Dashboard, you may see a number of cisco-mso service: Replicaset() not in desired state errors in the Cluster Configuration page.

Cause

The errors are displayed while the service is restarting and will resolve on their own within 30-60 seconds.

Resolution

Simply wait for the services to recover and refresh the page.

Two-Factor Authentication (2FA) Not Prompting for Login Info

After the initial login using two-factor authentication, subsequent login attempts do not ask for username and password information and present a blank page instead.

Cause

The cookie timeout configured for the OIDC application is longer than the authentication token timeout set in the Nexus Dashboard.

Resolution

Clear your browser cache and the authentication process will work as expected.

Red Hat Enterprise Linux (RHEL) Deployments

You can view the installation logs by logging into your RHEL system and checking the /logs/ndlinux/ directory.

In order to run the common Nexus Dashboard troubleshooting commands described in the Troubleshooting sections, you must first access the Nexus Dashboard environment.

To access the Nexus Dashboard environment from your RHEL system:

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

  2. Run the attach-nd command to access the Nexus Dashboard environment.

    /usr/bin/attach-nd

    After you access the Nexus Dashboard environment, you can use all the common Nexus Dashboard commands described in the Troubleshooting section of this guide.

Unable to Connect to Site After APIC Configuration Import

When you onboard a Cisco APIC site to Nexus Dashboard, APIC configuration is updated to reflect the onboarding. If you subsequently import an earlier configuration in APIC, the site may show as unavailable in Nexus Dashboard or services.

Cause

Earlier site configuration does not contain information specific to the Nexus Dashboard cluster where it is onboarded.

Resolution

We recommend exporting APIC configuration after the site is onboarded in Nexus Dashboard for any future config restores.

To resolve the issue after it occurs, you can re-register the site in the Nexus Dashboard GUI:

  1. Log in to your Nexus Dashboard cluster.

  2. Navigate to Admin Console > Sites

  3. From the Actions (…​) menu next to the site, select Edit Site.

  4. In the Site Edit screen, check the Re-register Site checkbox and provide the site details again.

  5. Click Save.

Replacing Worker or Standby Nodes

Re-Adding Same Primary Node to Physical Cluster

This section describes how to re-add a primary node to a physical cluster. This scenario can happen if the node was accidentally or deliberately removed via configuration reset (such as acs reboot factory-reset) or vMedia re-install.

If you have a standby node in your cluster, simply convert the standby into a primary node as described in [Replacing Single Primary Node with Standby Node] and then add the old primary node as a new standby node as described in [Adding Standby Nodes].

If you need to completely replace (RMA) a primary node due to hardware failure and do not have a standby node available, follow the procedure described in [Replacing Single Physical Primary Node without Standby Node] instead.

To re-add the primary node to the same cluster:

  1. Ensure that the node is reset to factory settings.

    If the node is in a bad state, log in to the node as rescue-user and reset the node using the following command:

    # acs reboot factory-reset

  2. Log in to the Nexus Dashboard GUI using the management IP address of one of the healthy nodes.

  3. Navigate to System Resoruces > Nodes.

    The node you want to replace will be listed as Inactive in the UI.

  4. From the actions (…​) menu for the node, select Register.

    Register Node page will open.

  5. In the Register Node page, provide the required information and click Validate.

    For physical nodes, you need to provide the CIMC IP address and login information.

    For virtual nodes, the management IP address will be retained and you need to provide only the password for the rescue-user.

  6. Ensure the rest of the node information is accurate.

  7. Click Register to re-register the node and re-add it as a primary node to the cluster.

    It will take up to 20 minutes to bootstrap, configure, and re-add the node. After it’s done, the node will show as an Active primary node in the UI.

Replacing a Single Virtual Primary Node Without a Standby Node

This section describes how to recover from a primary node failure in a VMware ESX or Linux KVM virtual Nexus Dashboard cluster. The procedure involves deploying a brand new Nexus Dashboard node using the same form factor as the node which you are replacing and joining it as a primary node to the remaining cluster.

  1. Ensure that the failed node’s VM is powered down.

  2. Bring up a new Nexus Dashboard node.

    Bringing up an additional node in VMware ESX is described in [Deploying Additional Virtual Nodes in VMware ESX]. Note that you must bring up a node of the same type (OVA-App or OVA-Data) as the node you are replacing.

    Bringing up an additional node in Linux KVM is described in [Deploying Additional Virtual Nodes in Linux KVM].

    note.svg

    Ensure that you use the same exact network configuration settings as you used for the failed node.

  3. Power on the new node’s VM and wait for it to boot up.

  4. Log in to the Nexus Dashboard GUI.

    You can use the management IP address of one of the remaining healthy primary nodes.

  5. Replace the node.

    1. From the left navigation pane, select System Resources > Nodes.

      The node you are replacing will be listed as Inactive.

    2. Click the (…​) menu next to the inactive primary node you want to replace and select Replace.

      The Replace window will open.

    3. Provide the Management IP Address and Password for the node, then click Verify.

      The cluster will connect to the node’s management IP address to verify connectivity.

    4. Click Replace.

      It may take up to 20 minutes for the node to be configured and join the cluster.

Replacing a Single Physical Primary Node Without a Standby Node

The following section describes how to recover from a single primary node failure in a physical Nexus Dashboard cluster without a standby node. This procedure is for hardware issues that require it to be physically replaced. If the node is simply in a bad software state, you can use the acs reboot clean commands instead and re-add the same node to the cluster as described in Re-Adding Same Primary Node to Physical Cluster.

If your cluster has a standby node configured, we recommend using the steps described in [Replacing Single Primary Node with Standby Node] instead.

Before you begin

  • Ensure that at least 2 primary nodes are healthy.

    If two of the primary nodes are unavailable, you will need to manually restore the cluster as described in [Replacing Two Primary Nodes with Standby Nodes]

  • Ensure that the primary node you want to replace is powered off.

  • Prepare and deploy the new node as described in [Deploying Additional Physical Nodes].

  • Ensure that you have the same CIMC IP address and login information on the new node as you configured for the failed node.

    The remaining primary nodes will use the CIMC information to restore configuration to the new node.

  • Ensure that the new node is powered on and note down its serial number.

To replace a single failed primary node:

  1. Log in to your Nexus Dashboard GUI using the management IP of one of the other primary nodes.

  2. From the main navigation menu, select System Resources > Nodes.

  3. In the nodes list, find the Serial number of the node you want to replace and ensure that the node’s Status shows Inactive.

  4. In the Nexus Dashboard’s Nodes screen, select the inactive node by clicking the checkbox next to it.

  5. From the Actions menu, select Replace.

  6. In the New Serial Number field, provide the serial number of the new node and click Replace.

    After the process is completed, you will see the serial number of the old node updated to the new node’s serial number and the status will change to Active once the new primary has successfully joined the cluster.

When replacing a failed worker or standby node, you can simply delete the Inactive node from the GUI and then deploy a brand new worker or standby node as you typically would.

Before You begin

  • Ensure that the worker node you want to replace is powered off.

To replace a failed worker or standby node:

  1. Navigate to your Nexus Dashboard’s Admin Console.

  2. From the main navigation menu, select System Resources > Nodes.

  3. In the nodes list, find the Serial number of the node you want to replace and ensure that the node’s Status shows Inactive.

  4. Select the inactive node by clicking the checkbox next to it.

  5. From the Actions menu, select Delete.

    This will remove the failed node from the list.

  6. Power on the new node and add it as a new worker or standby node to the cluster as described in Managing Worker Nodes. or Managing Standby Nodes..

    You can use the same configuration parameters as you used to set up the old node.

Initial Cluster Bootstrap Issues

This section describes the different stages of the initial cluster bootstrap process and summarizes some common issues you may run into when first deploying your Nexus Dashboard cluster.

After you bring up the nodes and provide each node’s information during the GUI setup, the initial bootstrap process goes through a number of stages to bring up the nodes, configure the required information, and create the cluster. The bootstrap screen allows you to track the progress and indicates any issues that may come up:

503639.jpg
Figure 1. Bootstrap Progress

  • Bootstrap Master Node and Bootstrap Peer Nodes — bring up the first primary node with the management and data networks IP addresses you provided. Then brings up the 2nd and 3rd primary nodes with their respective IPs.

    If the process fails at one of these stages, connect to each node’s console and verify that all the information you provided is correct. You can view the configuration you provided using the acs system-config command.

    You can also check the bootstrap logs (/logs/k8/install.log) for additional details.

    Typically, you can resolve any issues caused by misconfiguration by resetting the node using acs reboot factory-reset and restarting the setup process.

  • Discover Cluster Members — establishes connectivity between all primary nodes in the cluster over the data network.

    Failures at this stage typically indicate misconfiguration of the data network IP address and the node being unable to reach its other 2 peers.

    You can use acs cluster masters command on any of the nodes to confirm the data IP you have provided.

    If the command does not return any information, use ip addr to check the data interface’s (bond0br) IP adress and ensure that all nodes' IPs are reachable from the other nodes.

    $ ip addr
[..]
6: bond0br: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether 52:54:00:e1:93:06 brd ff:ff:ff:ff:ff:ff
    inet 10.195.255.165/24 brd 10.195.255.255 scope global bond0br
       valid_lft forever preferred_lft forever
    inet6 fe80::5054:ff:fee1:9306/64 scope link
       valid_lft forever preferred_lft forever
[..]

  • Setup Security — sets up Key Management Service (KMS) to enable data encryption between the nodes.

    If the acs cluster masters command returns ca cert not found error, it indicates a KMS issue. For additional details, check the /logs/kms logs.

  • Setup Initial Cluster and Bootstrap Kubernetes Cluster — any failures during these stages typically indicate Kubernetes issues.

    You can get additional details from the logs in /logs/k8 on each node.

  • After the Bootstrap stages are complete, the process advances go to the Cluster Bringup stages.

    From Initialize System to the Wait for infra services to be ready stages finalize the cluster creation by bringing up the remaining services.

    At this stage, you can use the acs health command on any of the nodes to see which service is not coming up correctly. Then check the specific service’s logs in /logs/k8_infra/<service>

Multi-Cluster Connectivity Issues

The following sections list common issues with multi-cluster connectivity.

For additional information about connecting multiple clusters together, see [Multi-Cluster Connectivity].

Non-Primary Cluster Unable to Reconnect

If you clean reboot and redeploy a cluster that was part of a multi-cluster connectivity group, the group’s primary cluster will not be able to recognize it and will indicate that the cluster remains unreachable.

To resolve this issue, disconnect and reconnect the cluster:

  1. Log in to the primary cluster.

  2. Remove the cluster you re-deployed from the group.

    This is described in [Disconnecting Clusters].

  3. Re-add the cluster to the group.

    This is described in [Connecting Multiple Clusters].

Non-Primary Cluster Redeployed with Older Version

If for any reason you redeploy one of the non-primary clusters in the group with a version of Nexus Dashboard that does not support this feature, the primary cluster will still be able to connect to that cluster, but will not be able to retrieve any information and the UI will remain blank.

To resolve this issue, remove that cluster from the group:

  1. Log in to the primary cluster as a local admin user.

    If you log in with the remote user shared across all clusters, the UI page will remain blank.

  2. Remove the cluster you re-deployed from the group.

    This is described in [Disconnecting Clusters].

  3. Log out and log back in using the remote user you use to manage the multi-cluster connectivity and verify that UI loads correctly.

Generating Private Key and Self-Signed Certificate

Generating Private Key, Creating CSR, and Obtaining CA-Signed Certificate

This section provides an example of how to generate a private key, creat a certificate signing request (CSR), and obtain a certificate signed by a Certificate Authority (CA) for use in your Nexus Dashboard cluster.

If you want to generate both a key and a self-signed certificate, skip this section and follow the steps described in Generating Private Key and Self-Signed Certificate instead.

The configuration steps required to add the keys and certificates in the Nexus Dashboard GUI are described in the [Security] chapter.

  1. Generate private key.

    You can generate the private key on any platform that has OpenSSL installed or you can SSH into one of your Nexus Dashboard nodes as the rescue-user and perform these steps there.

    [rescue-user@localhost ~]$ openssl genrsa -out nd.key 2048
Generating RSA private key, 2048 bit long modulus
........................
.............
e is 65537 (0x10001)
[rescue-user@localhost ~]$ ls
nd.key

  2. Generate your CSR signed with the private key you generated in the first step.

    1. Create the CSR configuration file (csr.cfg) with the required information.

      An example configuration file is shown below:

      [req]
default_bits = 2048
distinguished_name = req_distinguished_name
req_extensions = req_ext
prompt = no
[req_distinguished_name]
countryName = US
stateOrProvinceName = Texas
localityName = Plano
organizationName = CSS
organizationalUnitName = DC
commonName = nd.dc.css
emailAddress = no-reply@mydomain.com
[req_ext]
subjectAltName = @alt_names
[alt_names]
DNS.1 = *.dc.css
IP.1 = 10.0.0.96
IP.2 = 10.0.0.97

    2. Generate your CSR.

      [rescue-user@localhost ~]$ openssl req -new -key nd.key  -out nd.csr  -config csr.cfg
[rescue-user@localhost ~]$ ls
csr.cfg  nd.csr  nd.key

      You can view the generated CSR using the following command:

      [rescue-user@localhost ~]$ openssl req -in nd.csr -text -noout

  3. Obtain a CA-signed certificate.

    In production deployments, you will provide the CSR (ca.csr) from the previous step to a public CA, such as IdenTrust or DigiCert, to obtain the CA-signed certificate (ca.crt).

  4. Verify the signed certificate.

    The following command assumes you copied the CA-signed certificate (ca.crt) into the same folder as the private key you generated.

    [rescue-user@localhost ~]$ openssl verify -verbose -CAfile ca.crt nd.crt
nd.crt: OK

  5. Add the contents of the generated files in your Nexus Dashboard’s GUI.

    Following the steps described in [Security Configuration], where you will need to provide the contents of the following 3 files generated in the previous steps:

    • Private key (nd.key)

    • Certificate Authority’s (CA) public certificate (ca.crt)

    • CA-signed certificate (nd.crt)

This section provides an example of how to generate a private key and custom certificates should you want to use them in your Nexus Dashboard cluster.

If you want to use a CA-signed certificate, skip this section and follow the steps described in Creating CSR, and Obtaining CA-Signed Certificate.

The configuration steps required to add the keys and certificates in the Nexus Dashboard GUI are described in the [Security] chapter.

  1. Generate private key.

    You can generate the private key on any platform that has OpenSSL installed or you can SSH into one of your Nexus Dashboard nodes as the rescue-user and perform these steps there.

    [rescue-user@localhost ~]$ openssl genrsa -out nd.key 2048
Generating RSA private key, 2048 bit long modulus
........................
.............
e is 65537 (0x10001)
[rescue-user@localhost ~]$ ls
nd.key

  2. Generate Certificate Authority (CA) key.

    To generate a self-signed CA, for example for lab and testing purposes, run the following command:

    [rescue-user@localhost ~]$ openssl genrsa -out ca.key 2048
Generating RSA private key, 2048 bit long modulus
..................
.............
e is 65537 (0x10001)
[rescue-user@localhost ~]$ ls
ca.key  nd.key

  3. Generate CSR for the CA.

    [rescue-user@localhost ~]$ openssl req -new -key ca.key -subj "/CN=Self/C=US/O=Private/ST=Texas" -out ca.csr
[rescue-user@localhost ~]$ ls
ca.csr  ca.key  nd.key

    You can view the generated CSR using the following command:

    [rescue-user@localhost ~]$ openssl req -in ca.csr -text -noout

  4. Create self-signed root certificate.

    [rescue-user@localhost ~]$ openssl x509 -req -in ca.csr -signkey ca.key -CAcreateserial -out ca.crt -days 3650
Signature ok
subject=/CN=Self/C=US/O=Private/ST=Texas
Getting Private key
[rescue-user@localhost ~]$ ls
ca.crt  ca.csr  ca.key  nd.key

    You can view the generated root certificate using the following command:

    [rescue-user@localhost ~]$ openssl x509 -in ca.crt -text -noout

  5. Generate your CSR signed with the private key you generated in the first step.

    1. Create the CSR configuration file (csr.cfg) with the required information.

      An example configuration file is shown below:

      [req]
default_bits = 2048
distinguished_name = req_distinguished_name
req_extensions = req_ext
prompt = no
[req_distinguished_name]
countryName = US
stateOrProvinceName = Texas
localityName = Plano
organizationName = CSS
organizationalUnitName = DC
commonName = nd.dc.css
emailAddress = no-reply@mydomain.com
[req_ext]
subjectAltName = @alt_names
[alt_names]
DNS.1 = *.dc.css
IP.1 = 10.0.0.96
IP.2 = 10.0.0.97

    2. Generate your CSR.

      [rescue-user@localhost ~]$ openssl req -new -key nd.key  -out nd.csr  -config csr.cfg
[rescue-user@localhost ~]$ ls
ca.crt  ca.csr  ca.key  csr.cfg  nd.csr  nd.key

      You can view the generated CSR using the following command:

      [rescue-user@localhost ~]$ openssl req -in nd.csr -text -noout

  6. Self-sign the certificate you generated.

    [rescue-user@localhost ~]$ openssl x509 -req -in nd.csr -CA ca.crt -CAkey ca.key -CAcreateserial -out nd.crt -days 3600
Signature ok
subject=/C=US/ST=Texas/L=Plano/O=CSS/OU=DC/CN=nd.dc.css/emailAddress=no-reply@mydomain.com
Getting CA Private Key
[rescue-user@localhost ~]$ ls
ca.crt  ca.csr  ca.key  ca.srl  csr.cfg  nd.crt  nd.csr  nd.key

  7. Verify the signed certificate.

    [rescue-user@localhost ~]$ openssl verify -verbose -CAfile ca.crt nd.crt
nd.crt: OK

  8. Add the contents of the generated files in your Nexus Dashboard’s GUI.

    Following the steps described in [Security Configuration], where you will need to provide the contents of the following 3 files generated in the previous steps:

    • Private key (nd.key)

    • Certificate Authority’s (CA) public certificate (ca.crt)

    • CA-signed certificate (nd.crt)

Updating NDO Configuration After Replacing Switch Devices Managed by NDFC

If your Nexus Dashboard Fabric Controller (NDFC) fabric is managed by Nexus Dashboard Orchestrator (NDO) and you replace one or more devices that are managed by the NDFC, you must ensure that NDO is aware of the new switch serial numbers.

The following sections provide a summary of the steps required to synchronize the new fabric device’s information with NDO.

Replacing a Core or Route Server (RS) Device

  1. Log in to NDFC.

  2. To replace a physical switch in a Fabric when using NDFC Easy Fabric mode, follow the Return Material Authorization (RMA) steps mentioned in the Cisco NDFC Fabric Controller Configuration Guide.

  3. Log in to NDO.

  4. Navigate to Infrastructure > Site Connectivity.

  5. Click Refresh on the Control Plane Configuration in the General Settings page where the RS/Core is present.

  6. Click Deploy.

Replacing a Leaf Switch

  1. Log in to NDFC.

  2. To replace a physical switch in a Fabric when using NDFC Easy Fabric mode, follow the Return Material Authorization (RMA) steps mentioned in the Cisco NDFC Fabric Controller Configuration Guide.

  3. Log in to NDO.

  4. Navigate to Application Management > Schema and click the Schema/Template for that Site/Device.

  5. Re-import VRF/Network that was present on the device:

    1. In the View Overview drop-down list, select the template.

    2. In the Template Properties section, click the VRF/Network from the VRFs box.

    3. Select the site from the Import drop-down list.

    4. Select the VRF after clicking VRF.

    5. Click Import.

Replacing Border Gateway (BGW) Devices

  1. Log in to NDFC.

  2. To replace a physical switch in a Fabric when using NDFC Easy Fabric mode, follow the Return Material Authorization (RMA) steps mentioned in the Cisco NDFC Fabric Controller Configuration Guide.

  3. Log in to NDO.

  4. Navigate to Infrastructure > Site Connectivity.

  5. Click Refresh on the site where BGW is present and click Deploy.

  6. Navigate to Application Management > Schema and click the Schema/Template for that Site/Device.

  7. Re-import VRF/Network that was present on the device:

    1. In the View Overview drop-down list, select the template.

    2. In the Template Properties section, click the VRF/Network from the VRFs box.

    3. Select the site from the Import drop-down list.

    4. Select the VRF after clicking VRF.

    5. Click Import.

Trademarks

THE SPECIFICATIONS AND INFORMATION REGARDING THE PRODUCTS IN THIS MANUAL ARE SUBJECT TO CHANGE WITHOUT NOTICE. ALL STATEMENTS, INFORMATION, AND RECOMMENDATIONS IN THIS MANUAL ARE BELIEVED TO BE ACCURATE BUT ARE PRESENTED WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED. USERS MUST TAKE FULL RESPONSIBILITY FOR THEIR APPLICATION OF ANY PRODUCTS.

THE SOFTWARE LICENSE AND LIMITED WARRANTY FOR THE ACCOMPANYING PRODUCT ARE SET FORTH IN THE INFORMATION PACKET THAT SHIPPED WITH THE PRODUCT AND ARE INCORPORATED HEREIN BY THIS REFERENCE. IF YOU ARE UNABLE TO LOCATE THE SOFTWARE LICENSE OR LIMITED WARRANTY, CONTACT YOUR CISCO REPRESENTATIVE FOR A COPY.

The Cisco implementation of TCP header compression is an adaptation of a program developed by the University of California, Berkeley (UCB) as part of UCB’s public domain version of the UNIX operating system. All rights reserved. Copyright © 1981, Regents of the University of California.

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IN NO EVENT SHALL CISCO OR ITS SUPPLIERS BE LIABLE FOR ANY INDIRECT, SPECIAL, CONSEQUENTIAL, OR INCIDENTAL DAMAGES, INCLUDING, WITHOUT LIMITATION, LOST PROFITS OR LOSS OR DAMAGE TO DATA ARISING OUT OF THE USE OR INABILITY TO USE THIS MANUAL, EVEN IF CISCO OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.

Any Internet Protocol (IP) addresses and phone numbers used in this document are not intended to be actual addresses and phone numbers. Any examples, command display output, network topology diagrams, and other figures included in the document are shown for illustrative purposes only. Any use of actual IP addresses or phone numbers in illustrative content is unintentional and coincidental.

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First Published: 2023-01-31
Last Modified: 2023-04-11

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