Vprotect: Hyper-v Backups fail with (export) Internal server error

Summary: Hyper-V backup fails with vProtect error "ExternalAPIException: Internal Server Error"

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Symptoms

The backup fails with "ExternalAPIException: Internal Server Error"

Check the node logs for the error shown below: 
[2024-04-10 20:24:18.531] ERROR [pool-5-thread-6] HypervRequestSender.send:43
[e4b640a5-7784-4195-a909-6294d3763d0f] ApiException, code 500

[2024-04-10 20:24:18.531] ERROR [pool-5-thread-6] ExportTask.run:135
[e4b640a5-7784-4195-a909-6294d3763d0f] Backup task failed:

com.dell.vprotect.engine.exception.ExternalAPIException: Internal Server Error
        at com.dell.vprotect.engine.hypervisor.hyperv.HypervRequestSender.send(HypervRequestSender.java:48) ~[engine.jar:?]
        at com.dell.vprotect.engine.hypervisor.hyperv.HypervApi.createAndUploadRctMap(HypervApi.java:283) ~[engine.jar:?]
        at com.dell.vprotect.engine.hypervisor.hyperv.vmexport.DdBoostExport.createAndUploadRctMapToDdBoostAndUpdateBackupFiles(DdBoost
Export.java:221) ~[engine.jar:?]
        at com.dell.vprotect.engine.hypervisor.hyperv.vmexport.DdBoostExport.lambda$exportIncremental$6(DdBoostExport.java:163) ~[engin
e.jar:?]

Check the Hyper-V vProtect agent logs, and the error will be similar to: 
2024/04/10 20:27:06.761 [e4b640a5-7784-4195-a909-6294d3763d0f] Microsoft.Management.Infrastructure.CimException: The WS-Management service cannot process the request. The computed response packet size (585610) exceeds the maximum envelope size that is allowed (512000).
   at Microsoft.Management.Infrastructure.Internal.Operations.CimSyncEnumeratorBase`1.MoveNext()
   at System.Linq.Enumerable.SingleOrDefault[TSource](IEnumerable`1 source)
   at Microsoft.Management.Infrastructure.CimSession.InvokeMethod(String namespaceName, CimInstance instance, String methodName, CimMethodParametersCollection methodParameters, CimOperationOptions options)

Cause

The default size of WSMan:\localhost\MaxEnvelopeSizeKb is 500 (Kilobytes) which is 512,000 bytes.

If the agent attempts to transfer more data over DDboost than this, an exception is thrown.

Resolution

Access the hypervisor hosting the Virtual Machine which has the failing backup.
Check the size of WSMan:\localhost\MaxEnvelopeSizeKb (with PowerShell as administrator) 
PS C:\Users\Administrator> Get-Item -Path WSMan:\localhost\MaxEnvelopeSizeKb


   WSManConfig: Microsoft.WSMan.Management\WSMan::localhost

Type            Name                           SourceOfValue   Value
----            ----                           -------------   -----
System.String   MaxEnvelopeSizekb                              500


PS C:\Users\Administrator>

Increase the value from the default of 500 to a value greater than the number of bytes being sent 
PS C:\Users\Administrator> Set-Item -Path WSMan:\localhost\MaxEnvelopeSizeKb 600
PS C:\Users\Administrator> Get-Item -Path WSMan:\localhost\MaxEnvelopeSizeKb


   WSManConfig: Microsoft.WSMan.Management\WSMan::localhost

Type            Name                           SourceOfValue   Value
----            ----                           -------------   -----
System.String   MaxEnvelopeSizekb                              600


PS C:\Users\Administrator>

Re-Run the backup

Affected Products

vProtect
Article Properties
Article Number: 000224451
Article Type: Solution
Last Modified: 06 Mar 2025
Version:  2
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