PPDM: Resolve Nutanix Backup Error “Unable to Validate Resource - No Disks Identified”

Summary: Nutanix backup failed with error "Unable to validate resource: BackupPrismJobSessionsConfig validation failed: no disks identified" because the Virtual Machine had no attached disk; adding a disk resolved the issue and backup succeeded. ...

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Symptoms

Backup Failure Observed

The backup operation does not complete and reports an error related to missing disks.

  • Backup job fails with the error message: Unable to validate resource: BackupPrismJobSessionsConfig validation failed: No disks identified.
  • The job log contains a 400 error response indicating the same validation failure.
  • Log entry shows the failure occurring during session creation.
ghvdm.2025-12-04.0.log.gz: 2025-12-04T09:11:36.366Z ERROR [] [pool-15-thread-10] [00000000-0000-4000-a000-000000000000][][][TRACE_ID:bb1168592e17077c;JOB_ID:9ce19fe5bc0627b6][] [c.e.d.v.c.VProxyManager.error(1125)] -  Create session failed: code=400, text=Unable to validate resource:  BackupPrismJobSessionsConfig validation failed: no disks identified, response={"Text":"Unable to validate resource:  BackupPrismJobSessionsConfig validation failed: no disks identified","Code":-400}

Cause

Backup Validation Failure Due to Missing VM Disk

The backup job could not create a session because the target virtual machine had no attached disks. During validation, the BackupPrismJobSessionsConfig check failed, triggering a 400 error response.

Resolution

Fixing “BackupPrismJobSessionsConfig validation failed: no disks identified” error

Prerequisites

  • Access to Nutanix Prism (Web UI) with administrator privileges.
  • Knowledge of the VM that is failing the backup.
  • Available storage capacity on the target storage container

Step‑by‑step procedure

  • Log in to Prism Central or Prism Element using your admin credentials.
  • Navigate to VMs > List of VMs and locate the affected VM.
  • Select the VM and click Update (or Edit).
  • In the **Disks** section, click **Add Disk**.
  • Configure the new disk:
    • Choose the appropriate Storage Container.
    • Specify a **size** that meets your workload requirements.
    • Set the **Disk Type** (e.g., SSD or HDD) as needed.
  • Save the changes. If the VM is powered on and supports hot‑add, the disk appears immediately; otherwise, power off the VM, apply the change, then power it back on.
  • Return to the **Protection Domain** or **Backup Schedule** that contains the failing job.
  • Manually trigger the backup or wait for the next scheduled run.

Verification

  • Open the backup job log and confirm that the previous error message no longer appears.
  • Check the job status; it should show **Succeeded**.
  • Optionally, run a quick test restore to ensure data integrity.
Caution: Adding a disk increases the VM’s storage consumption. Verify that the selected storage container has sufficient free space to avoid over‑provisioning.
Caution: If the VM does not support hot‑add, powering it off is required. Plan for any potential service interruption.
Note: After adding the disk, the backup job may take longer than usual because the new volume must be scanned for the first time.
Warning: Do not modify the VM’s disk configuration while a backup job is running. Cancel any in‑progress jobs before making changes.
Contact Dell Support: If you encounter any issues adding the disk, experience unexpected VM behavior, or the backup still fails after following these steps, open a support ticket with Dell Technologies.

Affected Products

PowerProtect Data Manager
Article Properties
Article Number: 000402626
Article Type: Solution
Last Modified: 15 ديسمبر 2025
Version:  1
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