Unregister or Remove Nutanix Cluster from Prism Central

Managing Nutanix environments becomes easier when administrators understand how Prism Element and Prism Central work together. However, situations often arise where you must unregister or remove a Nutanix cluster from Prism Central. This could be due to cluster decommissioning, IP address changes, Prism Central failures, multi-cluster clean-up activities, or configuration resets.

Managing Nutanix clusters efficiently is key to keeping your IT environment organized. Sometimes, you may need to unregister or remove a Nutanix cluster from Prism Central—for example, when decommissioning hardware, migrating workloads, or cleaning up unused resources.

In this guide, i will explain the simple steps to safely remove a Nutanix cluster from Prism Central. Whether you’re an IT beginner or experienced professional, following best practices will keep your Nutanix infrastructure streamlined and easy to manage.

Below are the most common real-world scenarios where you can remove or unregister a Nutanix cluster from Prism Central.

What Is Nutanix Prism Central

Nutanix Prism Central is a centralised management plane that allows organisations to manage multiple Nutanix clusters from a single dashboard. Instead of managing each cluster individually, Prism Central brings everything under one unified view.

Nutanix Prism Central offer following capabilities:

• Manage multi-cluster environments
• Monitor performance and capacity
• Deploy and scale applications
• Perform automation and lifecycle operations
• Manage security policies
• Create global alerts and reporting

For large-scale environments, Prism Central becomes the “brain” of the entire Nutanix HCI ecosystem.

Nutanix Prism Central vs Prism Element

Nutanix Prism Element and Prism Central serve different roles within a Nutanix environment, but both works together to simplify HCI management.

Prism Element is the built-in management interface for a single Nutanix cluster. It handles day-to-day tasks such as VM operations, storage configuration, performance monitoring, and hardware health. Read more about Nutanix Prism architecture and how it works

Prism Central, on the other hand, is designed for multi-cluster environments. It provides a unified management layer that adds advanced capabilities such as centralized governance, automation, global analytics, security policies, and lifecycle management across all connected clusters. In simple terms, Prism Element manages one cluster, while Prism Central manages many.

Nutanix Prism Central and Prism Element detailed comparison is described below:

Read more: What is Nutanix HCI – Hyperconverged Infrastructure Solution

Prism Central Default Username and Password

When Prism Central is deployed fresh, the default credentials are:

• Username: admin
• Password: Nutanix/4u (or the password entered during initial setup)

If administrators change the default credentials, the updated ones must be used for future access.

If you want to reset Nutanix Prism Central Password Read more details on How to Reset Nutanix Prism Central Password

Why Register or Unregister a Nutanix Cluster from Prism Central

Managing Nutanix environments often requires administrators to register Prism Element clusters with Prism Central or remove them when the environment changes. Both actions serve different operational purposes and help maintain a clean, healthy, and scalable Nutanix infrastructure.

The following sections clearly explain the reasons for both Nutanix Cluster’s registration and unregistration in simple, real-world use-cases.

#1. Why Register a Nutanix Cluster (Prism Element) with Prism Central

Administrators register a Nutanix cluster with Prism Central to centralise management, improve visibility, and simplify operations across multiple clusters. The goal is to achieve unified control, automation, and analytics on a single platform.

Registering a cluster with Prism Central creates a single management plane where administrators can control multiple Nutanix clusters without logging in to each Prism Element individually. This helps reduce operational overhead and improves visibility, consistency, and automation across the entire Nutanix ecosystem.

Registration Reasons:

• ➤ Centralised multi-cluster management from one dashboard
• ➤ Unified monitoring, alerts, reporting, and capacity analytics
• ➤ Role-based access control and improved governance
• ➤ Simplified lifecycle management and upgrades
• ➤ Application automation and policy-based orchestration
• ➤ Consistent configuration compliance across all clusters
• ➤ Scaling infrastructure without increasing management complexity
• ➤ Enabling advanced Nutanix features available only in Prism Central

Read more: How to troubleshoot Nutanix Prism Web-UI is not working or not accessible

#2. Why Unregister or Remove a Nutanix Cluster from Prism Central

Administrators unregister or remove Nutanix clusters or Nutanix Prism Element Cluster when they are no longer needed, when their state changes, or when Prism Central experiences issues that require re-registration or cleanup.

As environments evolve, administrators often need to disconnect or remove a cluster from Prism Central. This usually happens during infrastructure renewal, Prism Central rebuilds, cluster decommissioning, or after network changes that require re-registration. Properly unregistering prevents stale objects, stale connections, and errors such as cluster blacklisting.

Unregistration Reasons:

• ➤ Cluster has been decommissioned or retired
• ➤ Prism Central VM is corrupted, replaced, or rebuilt
• ➤ Network or IP address changes require fresh registration
• ➤ Cluster appears as unreachable, stale, or “disconnected”
• ➤ Cluster is blacklisted or incorrectly registered
• ➤ Removing duplicate or incorrect entries to prevent conflicts
• ➤ Prism Central migration to a new deployment
• ➤ Cleaning environment before re-adding the cluster

Methods to Unregister or Remove a Nutanix Cluster from Prism Central

Managing Nutanix clusters often requires cleanup or reconfiguration, and one common task is unregistering or removing a Nutanix cluster from Prism Central. This ensures that only active, relevant clusters remain visible, helping administrators maintain a streamlined and accurate environment.

There are different methods available to perform this action, depending on whether you prefer using the Prism Central UI or command‑line tools. In this guide, i will outline the key approaches to safely unregister or remove a Nutanix cluster, making cluster management simpler and more efficient for IT teams.

Below are the most common real-world scenarios where administrators need to remove or unregister a Nutanix cluster from Prism Central.

Let’s explorer Top #3 methods step by step with their real-world use-cases to unregister Nutanix Prism Cluster from Nutanix Prism Central.

Method #1: If Nutanix Prism Element Cluster Is Reachable from Prism Central

Managing Nutanix infrastructure often requires unregistering or removing a cluster from Prism Central. This process is important when you want to decommission a cluster, perform maintenance, or simply clean up your environment.

In Method #1, the focus is on situations where the Nutanix Prism Element cluster is still reachable from Prism Central. By following this method, administrators can safely disconnect the cluster without affecting other resources.

This is the simplest scenario. The cluster is healthy, Prism Element is accessible, and Prism Central is functioning.

Step 1: Login to Nutanix Prism Element CVM (CVM) with admin ID (User ID is nutanix)

If you have forgot Nutanix Prism Element built-in nutanix admin Password you can reset, read this article:
Read more details on How to Reset Nutanix Prism Password

Step 2: Run following command to check Nutanix Prism Element Cluster health & Services

nutanix@cvm$ cluster status

Step 3: Run following command to unregister or remove Nutanix Prism Element Cluster from Prism Central

nutanix@cvm$ ncli multicluster remove-from-multicluster external-ip-address-or-svm-ips= <pc_name_or_ip> username=<pc_admin_username> password=<PC_password>

Example: ncli multicluster remove-from-multicluster external-ip-address-or-svm-ips=192.168.10.100 username=admin password=P@ssw0rd@12345#

Note: Replace all highlighted info with your Prism Central IP address and Credentials. If you forgot your Nutanix Prism Central UserID and Password. Read this article to How To Reset Nutanix Prism Central Password with easy steps.

Step 4: Login to Nutanix Prism Central to confirm Prism Element cluster removal or un-registration and metadata clean up.

Use Prism Central admin Login ID: nutanix

Run following command to get Prism Element Cluste UUID

nutanix@cvm$ ncli cluster info

Output would be like this.
Prism Cluster Cluster Id  : 0006a8gc-4779-1288-457d-aq1f8b3vdfs9 
Cluster Name       : Prism Cluster 01

Note: Just copy Cluster ID aka Cluster UUID i.e. 0006a8gc-4779-1288-457d-aq1f8b3vdfs9

Step 5: Run following PYTHON SCRIPT command on Prism Central to clean up Prism Element cluster metadata

nutanix@pcvm$ python /home/nutanix/bin/unregistration_cleanup.py <uuid>

Example: python /home/nutanix/bin/unregistration_cleanup.py 0006a8gc-4779-1288-457d-aq1f8b3vdfs9

Note: After running the above python clean-up command wait for up to one hour to reflect changes on Prism Central and Prism Cluster.

Method 2# Prism Element Cluster Was Decommissioned but Not Removed from Prism Central

When a Nutanix Prism Element cluster is decommissioned, administrators often shut down or remove the hardware without unregistering it from Prism Central. This leaves behind a stale or disconnected entry that Prism Central continues to track. As a result, Prism Central raises alerts, displays the cluster as unreachable, and may block future registrations due to outdated records.

These orphaned or destroyed cluster entries can create confusion during audits, upgrades, or capacity planning. Cleaning them up is important to maintain an accurate management view and avoid issues such as blacklisting, failed registrations, or incorrect cluster associations within Prism Central.

If you have decommissioned your Nutanix Prism Cluster or unreachable from Prism Central follow below steps to step guide to unregister or remove from Prism Central.

Note: In this Case Nutanix Prism Element Cluster does not exists. Following commands needs to be executed on Prism Central (PCVM) only.

Step 1: Login to Nutanix Prism Central VM (PCVM) using Admin ID credentials.

Use Prism Central admin Login ID: nutanix

Run following command to get Prism Element Cluste UUID

nutanix@PCVM$ ncli cluster info

Output would be like this.
Prism Cluster Cluster Id  : 0006a8gc-4779-1288-457d-aq1f8b3vdfs9 
Cluster Name       : Prism Cluster 01

Note: Just copy Cluster ID aka Cluster UUID i.e. 0006a8gc-4779-1288-457d-aq1f8b3vdfs9

Step 2: Run following command to unregister / remove Prism Element cluster (Already decommissioned) or unreachable from Nutanix Prism Central.

nutanix@PCVM$ ncli multicluster remove-prism-element cluster-id=<Prism Element Cluster UUID>

Example: nutanix@PCVM$ ncli multicluster remove-prism-element cluster-id=0006a8gc-4779-1288-457d-aq1f8b3vdfs9

Important:

Sometime above command does not work effectively and need to forcefully delete the Prism Element cluster entry from Prism Central to run anther command as mentioned in step 3 below:

Step 3: Run following command to forcefully remove Nutanix Prism Element Cluster entry from Prism Central inventory list.

nutanix@PCVM$ ncli multicluster delete-cluster-state cluster-id=<Prism Element Cluster UUID>

Step 4: Run following PYTHON SCRIPT command on Prism Central to clean up Prism Element cluster metadata from Prism Central

nutanix@pcvm$ python /home/nutanix/bin/unregistration_cleanup.py <uuid>

Example: python /home/nutanix/bin/unregistration_cleanup.py 0006a8gc-4779-1288-457d-aq1f8b3vdfs9

Note: After running the above python clean-up command wait for up to one hour to reflect changes on Prism Central.

Method 3# Prism Central Was Decommissioned but Not Removed from Prism Element Cluster

There are many situations where Prism Central is decommissioned, rebuilt, or unexpectedly removed, but the associated Nutanix Prism Element cluster still retains its registration details. In this case, Prism Element continues to believe that it is linked to an active Prism Central instance, even though that instance no longer exists on HCI cluster.

This leads to repeated connection failures, stale status information, and errors when you attempt to register the cluster with a new Prism Central deployment. To correct this, administrators must manually remove the old Prism Central reference from the Prism Element cluster using command-line tools on the Controller VM (CVM).

Clearing this association ensures a clean state, prevents registration conflicts, and allows the cluster to integrate smoothly with a newly deployed Prism Central environment.

This happens when:

• Prism Central VM is deleted
• Prism Central VM is corrupted
• Prism Central database becomes unusable
• Prism Central migration fails

Goal: Remove the Prism Central reference from Prism Element so you can register it with a new Prism Central instance.

Note: In this Case Nutanix Prism Central does not exists. Following commands needs to be executed on Prism Element Cluster from (any CVM) only.

Step 1: Login to Nutanix Element Cluster VM (any CVM) using Admin ID credentials.

Use Prism Element Cluster’s CVM admin Login ID: nutanix

Run following command to get Prism Central Cluste UUID

nutanix@CVM$ ncli cluster info

Output would be like this.
Prism Central Cluster Id  : 0008a3ga-7770-3292-047w-dq9f1h7vkfa3 
Cluster Name       : Prism Central 01

Note: Just copy Cluster ID aka Cluster UUID i.e. 0008a3ga-7770-3292-047w-dq9f1h7vkfa3

Step 2: Run following command to forcefully remove Nutanix Prism Central entry from Prism Element cluster configuration file.

nutanix@CVM$ ncli multicluster delete-cluster-state cluster-id=<Prism Central UUID>

Example: nutanix@CVM$ ncli multicluster delete-cluster-state cluster-id=0008a3ga-7770-3292-047w-dq9f1h7vkfa3

Step 3: Run following PYTHON SCRIPT command on Prism Central to clean up Prism Element cluster metadata from Prism Central

nutanix@cvm$ python /home/nutanix/bin/unregistration_cleanup.py <uuid>

Example: python /home/nutanix/bin/unregistration_cleanup.py 0008a3ga-7770-3292-047w-dq9f1h7vkfa3

Note: After running the above python clean-up command wait for up to one hour to reflect changes on Prism Central.

Nutanix Prism Element Cluster Is Blacklisted on Prism Central

A Nutanix Prism Element cluster may appear as blacklisted in Prism Central when Prism Central blocks further registration attempts from that specific cluster. This usually happens after an incomplete removal, failed registration, or mismatched configuration between the two environments.

When a cluster is blacklisted, Prism Central prevents it from reconnecting until the blacklist entry is cleared manually. Administrators commonly face this issue during cluster migrations, Prism Central rebuilds, and IP changes. Understanding the root cause helps ensure a clean and successful re-registration.

Why a Nutanix Prism Element Cluster Gets Blacklisted on Prism Central

A cluster may be blacklisted due to one or more of the following conditions:

Most Common Technical Reasons

• ➤ Cluster was forcefully removed from Prism Central
• ➤ Previous registration attempt failed and left behind stale metadata
• ➤ Prism Central detected an authentication mismatch during handshake
• ➤ Incorrect admin credentials used repeatedly during registration
• ➤ Prism Central services restarted or crashed mid-registration
• ➤ Network interruption during registration or unregistration
• ➤ SSL certificate mismatch or outdated TLS handshake

Environmental and Configuration Reasons

• ➤ Cluster IP changed without unregistering the old record first
• ➤ Prism Central VM was rebuilt or redeployed, causing metadata orphaning
• ➤ Duplicate cluster UUID detected after hardware replacement or rebuild
• ➤ Prism Central database corruption or metadata inconsistency
• ➤ Multiple Prism Central instances trying to register the same cluster
• ➤ Cluster was added to Prism Central older than the supported compatibility matrix
• ➤ Accidentally attempting registration on a secondary or outdated Prism Central

Administrative or Operational Reasons

• ➤ Unregister option was not used before cluster decommissioning
• ➤ Forced shutdown of Prism Central during cluster registration
• ➤ Cluster was previously removed using unsupported methods
• ➤ Prism Central is overloaded or not fully healthy during registration
• ➤ Incorrect API use through Python or automation tools

All these situations lead Prism Central to mark the cluster as blacklisted to avoid duplicate, conflicting, or unstable registrations.

How to Register a Blacklisted Nutanix Prism Element Cluster on Prism Central

To re-register a blacklisted HCI cluster, you must clear the blacklist entry from Prism Element and ensure both sides start fresh. The process uses NCLI commands on the Controller VM (CVM).

Step 1: Check Current Multi-Cluster State on Prism Element

Log in to any CVM and run:

nutanix@cvm$ ncli multicluster get-cluster-state

This displays existing Prism Central associations and the current blacklist status.

Step 2: Clear the Blacklisted Entry

Use the following NCLI command:

nutanix@cvm$ ncli multicluster clear-blacklist external-ip=<Prism-Central-IP>

Replace <Prism-Central-IP> with your actual Prism Central IP address.

This removes the stale record and allows a fresh registration attempt.

Step 3: Remove Old or Broken Prism Central Link (If Applicable)

If Prism Element still shows the old association:

nutanix@cvm$ ncli multicluster remove-from-multicluster external-ip=<Prism-Central-IP>

This cleans up any remaining multi-cluster references.

Step 4: Validate Network Connectivity

Ensure Prism Element can reach Prism Central:

nutanix@cvm$ curl -k https://<Prism-Central-IP>:9440

You should receive an HTML response.

Also verify DNS, routing, and firewall rules for port 9440.

Step 5: Register the Cluster Again with Prism Central

Run the registration command:

nutanix@cvm$ ncli multicluster add-to-multicluster external-ip=<Prism-Central-IP> \
username=admin password=<Prism-Central-Admin-Password>

This initiates a fresh handshake with Prism Central.

Step 6: Verify Registration from Prism Central

Log in to Prism Central → Infrastructure → Clusters

You should now see the cluster in a connected and healthy state.

Important Recommendations to Avoid Blacklisting in Future

Preventing cluster blacklisting is essential for maintaining a stable relationship between Prism Element and Prism Central. Blacklisting usually occurs due to incomplete unregister operations, IP changes, misconfigurations, or failed registration attempts.

By following best practices and ensuring proper cleanup before re-registration, administrators can avoid repeated connection issues and maintain a healthy, predictable multi-cluster environment.

The following recommendations outline the key steps needed to prevent future blacklisting and ensure smooth cluster-to-Prism Central communication.

• ➤ Always unregister a cluster before shutting down or decommissioning it
• ➤ Avoid using old Prism Central snapshots as backup (causes metadata mismatch)
• ➤ Ensure time synchronization between PC and PE
• ➤ Maintain proper network stability during registration
• ➤ Follow Nutanix compatibility matrix when upgrading or migrating clusters
• ➤ Use supported methods only (NCLI, Prism UI, or APIs)
• ➤ Never attempt multi-cluster registration on multiple Prism Central instances simultaneously

Frequently Asked Questions (FAQs)

Unregistering, Removing, and Re-Registering Nutanix Clusters from Prism Central

These commonly asked questions help administrators understand real-world issues that occur when managing Nutanix clusters, Prism Element, and Prism Central. I have mentioned each answer in a simple language with maximum clarity.

Conclusion and Key Recommendations

Unregistering, removing, or re-registering a Nutanix Prism Element cluster from Prism Central is a crucial part of maintaining a clean and healthy Nutanix environment. A properly managed registration process prevents blacklisting, stale entries, and connection conflicts that commonly disrupt multi-cluster operations. Following the right steps keeps Prism Central accurate, stable, and ready for automation, lifecycle management, and advanced HCI features.

My Key Recommendations for Clean and Reliable Prism Central Management

1. Always unregister the cluster before decommissioning hardware
   Prevents stale or disconnected entries inside Prism Central.
2. Clear old Prism Central associations before rebuilding or redeploying PC
   Avoids metadata mismatches and blacklisting.
3. Unregister before changing cluster IP or cluster name
   Ensures Prism Central does not treat the updated cluster as a duplicate.
4. Check multicluster state regularly using NCLI
   Helps detect stale entries, misconfigurations, or broken associations early.
5. Avoid restoring old Prism Central snapshots
   They often reintroduce outdated metadata or cause UUID conflicts.
6. Ensure reliable connectivity on port 9440
   Even minor network interruptions can cause incomplete registration and blacklist issues.
7. Maintain accurate time synchronization between Prism Element and Prism Central
   Time drift can break registration handshakes and cause authentication failures.
8. Use supported CLI commands (remove-from-multicluster, clear-blacklist) for cleanup
   Prevents accidental corruption of management data.
9. Document cluster registration activities
   Helps future administrators understand cluster history and avoids repeated mistakes.
10. Verify compatibility between Prism Element and Prism Central versions
    Mismatched versions often cause silent registration failures.

By following these recommendations, administrators can maintain a clean and error-free connection between Prism Element and Prism Central, ensuring stable performance, smooth upgrades, and reliable multi-cluster management.