Avamar: Snapshot Cannot Be Performed When ESXi Host Is in Maintenance Mode

Summary: VMware image backups fail with avvbimage Error <17780>. ESXi host is in Maintenance Mode or Avamar MCS has outdated VM‑to‑host-mapping information.

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Symptoms

Backup Failure Indicators

The following symptoms are observed when a VMware Image backup cannot be completed:

  • Backup job reports failure with the message “VMware Image backup fails”.
  • The Avamar client returns the error code 17780 indicating a snapshot issue.

Typical error output:

avvcbimage Error <17780>: Snapshot cannot be performed because Host 'esx-hostname' is currently in Maintenance Mode>

Cause

Two conditions can trigger this error:

Cause 1: The Virtual Machine (VM) resides on an ESXi host in Maintenance Mode.

  • When a host is in Maintenance Mode, VMware disables snapshot operations, preventing VADP-based backups.

Cause 2: The VM was moved (vMotion), but the Avamar MCS cache was not updated.

  • If the VM is not on the host listed in the error and has been vMotioned, the Avamar MCS VM cache may contain outdated host information.
    In this scenario, the work order is issued against the wrong ESXi host.

 

 

Resolution

Cause 1: VM located on a host in Maintenance Mode

  • This behavior is expected. Snapshot operations are disabled for any VM on a host in Maintenance Mode, and VADP backups cannot proceed.
  • Action:
    • Migrate the VM to an ESXi host that is not in Maintenance Mode and rerun the backup.

Cause 2: VM moved , but MCS cache was not updated.

  • Avamar MCS may continue to reference outdated VM‑to‑host mapping after vMotion events.
  • Workaround:
    • Manually synchronize MCS with vCenter to refresh the VM cache.
    1. Open Avamar Administrator.
    2. Right‑click the vCenter object.
    3. Select Synchronize with vCenter.
    4. Allow MCS to rebuild its VM-mapping cache, then retry the backup.

 

Additional Information

Example a powered off VM is located on an ESX server that is in maintenance mode. In that case nothing is wrong with MCS.

Affected Products

Avamar

Products

Avamar
Article Properties
Article Number: 000039321
Article Type: Solution
Last Modified: 10 Apr 2026
Version:  5
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