Migrating ESXi Boot Disk in VCF SDDC/vSAN Environment

Products

• VMware vSphere ESXi

Issue/Introduction

Users may need to migrate the boot disk of an ESXi host in a VMware Cloud Foundation (VCF) SDDC environment using vSAN storage. This process requires careful steps to ensure data integrity and minimize downtime.

Environment

- VMware Cloud Foundation (VCF) with SDDC Manager
- vSphere ESXi hosts
- vSAN storage
- Current boot configuration: Local disk
- Target boot configuration: iSCSI boot LUN

Cause

The need to migrate ESXi boot disks can arise from various reasons, including hardware upgrades, storage reconfiguration, or performance optimization.

Resolution

Follow these steps to safely migrate an ESXi host's boot disk in a VCF SDDC/vSAN environment:

1. Access the SDDC Manager user interface.

2. Locate and select the host you want to migrate.

3. Remove the host from the SDDC UI:
   a. This action will automatically evacuate vSAN data from the host.
   b. The host will be removed from the vSAN cluster.

4. Decommission the host from SDDC:
   a. In the SDDC Manager UI, find the option to decommission the host.
   b. Follow the prompts to complete the decommissioning process.

5. Handle the vSAN disk group:
   Option A: Remove the vSAN disk group
   a. If possible, remove the vSAN disk group from the host.
   b. This option is preferable if you're planning significant storage changes.

   Option B: Keep vSAN disks untouched
   a. If removal is not possible or advisable, ensure that the vSAN disks remain untouched.
   b. This is the more conservative approach and is recommended if you're unsure.

6. Rebuild the host with a new ESXi image:
   a. Install ESXi on the new boot media (e.g., iSCSI boot LUN).
   b. Ensure you're using a compatible ESXi version for your VCF environment.

7. Commission the host back into SDDC:
   a. In the SDDC Manager UI, initiate the process to add a new host.
   b. Follow the prompts to commission the rebuilt host.

8. Add the host back to the cluster via SDDC:
   a. Once commissioned, add the host to its original cluster.
   b. SDDC Manager will guide you through this process.
   c. Note: The vSAN disk groups will be automatically recreated during the SDDC host add automation.

9. Verify the host's status and functionality:
   a. Check that the host is fully operational in the vSphere Client.
   b. Verify that vSAN storage is correctly configured and accessible.
   c. Confirm that the vSAN disk groups have been automatically recreated.
   d. Run a health check on the cluster to ensure everything is functioning properly.

 

Additional Information

- Always ensure you have recent backups before performing major system changes.
- If you encounter issues during this process, contact VMware support for assistance.

- The automatic recreation of vSAN disk groups during the SDDC host add process eliminates the need for manual intervention in most cases.
- If you encounter any issues with vSAN disk groups after the automation, contact VMware support for assistance.

- For more detailed information on host management in VCF, refer to the VMware Cloud Foundation documentation.

Managing ESXi Hosts in VMware Cloud Foundation

Add a Host to a vSphere Cluster Using the SDDC Manager UI