SRM Reprotect Fails with “Unable to Serialize Response for method associateAndApplyVsanEntities”
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SRM Reprotect Fails with “Unable to Serialize Response for method associateAndApplyVsanEntities”

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Article ID: 420598

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Updated On:

Products

VMware Live Recovery VMware vCenter Server VMware vSAN

Issue/Introduction

When attempting to reverse replication (reprotect/failback) in Site Recovery Manager (SRM) after a successful failover, the reprotect operation fails. The SRM interface displays the following error:

Error in the SRM GUI:
Unable to reverse replication for the virtual machine ‘<VM Name>’. A general system error occurred: Unable to serialize response for method associateAndApplyVsanEntities.


Errors in /var/log/vmware/vmware-sps/sps.log on vCenter appliance:
2025-11-19T10:44:20.072-08:00 [pool-4-thread-8] ERROR opId=a56c263b-e767-4668-81dd-##########-reprotect:7a88:e624:7d5f-HMS-43886937 com.example.pbm.profile.impl.VsanEntityServiceImpl - Exception in associate profile:
com.example.common.util.concurrent.UncheckedExecutionException: java.lang.NullPointerException

2025-11-19T10:44:20.074-08:00 [pool-4-thread-19] ERROR opId=a56c263b-e767-4668-81dd-##########-reprotect:7a88:e624:7d5f-HMS-43886937 com.example.vim.vmomi.server.http.impl.CompletionContinuerTask - Failed to serialize response
com.example.vim.binding.vmodl.fault.SystemError: Failed to serialize response

The failure occurs when SRM attempts to reapply storage policies through vCenter and the Storage Policy Service (SPS).

Environment

 

  • VMware Site Recovery Manager (SRM)

  • vCenter Server

  • vSAN environment

    This issue may occur in any environment where SRM reprotect operations rely on vSAN storage policies.

 

Cause

The reprotect operation fails because at least one vSAN datastore in the vCenter inventory contains invalid metadata, specifically an unset or null aliasOf property.

During reprotect, SRM triggers PBM/SPS to evaluate all vSAN datastores in the environment. PBM uses the aliasOf property to identify the vSAN cluster associated with each datastore. If the property is missing or null on any datastore, PBM fails to resolve the datastore mapping and throws a NullPointerException, which stops the reprotect workflow.

Common reasons for a missing aliasOf value include:

  • A vSAN datastore was removed or decommissioned incorrectly

  • VMs reference files (e.g., ISOs or floppy images) from a datastore that no longer exists

  • Stale VSAN datastore metadata remains in vCenter

  • VMX files contain references to outdated or removed virtual hardware devices

Because PBM evaluates all vSAN datastores, a single invalid datastore entry can cause reprotect to fail, even if affected VMs never used that datastore.

Resolution

1. Identify vSAN datastores

  1. In the vCenter GUI, the problematic vSAN datastore may show with 0 capacity:

2. Inspect each vSAN datastore for the aliasOf property

Access the MOB

  1. Log into the MOB using [email protected]:

    https://<vcenter-ip>/mob

  2. Click Content.

  3. Scroll to the root folder (e.g., group-d1) and click it.

  4. Select the appropriate Datacenter (there may be more than one).

  5. In the Datacenter view, identify each datastore’s MOID (e.g., datastore-16) and friendly name.

  6. Click each datastore to view associated VMs (useful for remediation), then click INFO.

    7. Locate the aliasOf field.

     

  • Verify that vSAN datastores have a valid value.

    • Problem condition: aliasOf is null, unset, or empty.

    • Note: Non-vSAN datastores legitimately show Unset, but vSAN datastores must not.

A vSAN datastore with a missing or incorrect aliasOf value causes PBM/SPS failures and must be corrected by resolving the underlying stale reference.

 

3. Fix stale datastore references

Depending on what is causing the invalid datastore entry:

Case A - VM referencing files on a removed datastore

Examples:

  • ISO mounted from a deleted datastore

  • Tools image stored on old storage

Resolution:

  • Unmount or remove the ISO/virtual device

  • Refresh the vCenter inventory

Case B - VMX file referencing removed hardware

Example:
floppy0.fileName = "/vmfs/volumes/<old-datastore>/image.flp"

Resolution:

Case C - Orphaned vSAN datastore

Resolution:

4. Restart SPS service (may not be required)

After correcting invalid datastore metadata:

service-control --restart vmware-sps

 

Lastly, retry the SRM reprotect operation.

Additional Information

 

  • PBM/SPS must successfully read VSAN datastore metadata during reprotect to reapply storage policies.

  • The aliasOf property uniquely identifies VSAN cluster relationships; without it, PBM cannot validate or reassign storage policies.

  • This issue may not generate obvious storage or host errors, only PBM/SRM workflows may be affected.

 

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