When taking VSS snapshot with Hyper-V VSS writer on Windows 2012 R2, there are frequently some warning/error logs in Windows Event log. This will make the Hyper-V VSS writer goes to a bad state and in BCD, the BACKUP_METADATA is also missing for the problematic VM.
The logs in Windows Event log are as below:
In Windows Log->Application, there will be logs as:
A VSS writer has rejected an event with error 0x800423f4, The writer experienced a non-transient error. If the backup process is retried,
the error is likely to reoccur.
. Changes that the writer made to the writer components while handling the event will not be available to the requester. Check the event log for related events from the application hosting the VSS writer.
Operation:
PrepareForSnapshot Event
Context:
Execution Context: Writer
Writer Class Id: {66841cd4-6ded-4f4b-8f17-fd23f8ddc3de}
Writer Name: Microsoft Hyper-V VSS Writer
Writer Instance ID: {fec29c4d-410b-4854-96b4-9637f3a24fdc}
Command Line: C:\Windows\system32\vmms.exe
Process ID: 2024
In Hyper-V-VMMS there are logs as:
Could not create backup checkpoint for virtual machine '********': Overlapped I/O operation is in progress. (0x800703E5). (Virtual machine ID 2AD8D389-65AE-45F7-89F8-FDF2F08CE3C2)
In Hyper-V-Worker there are logs as:
'******'has encountered a fatal error. The guest operating system reported that it failed with the following error codes: ErrorCode0: 0x7A, ErrorCode1: 0x10EC78, ErrorCode2: 0xC000000E, ErrorCode3: 0x1BA09BE0, ErrorCode4: 0x21D8F000. If the problem persists, contact Product Support for the guest operating system. (Virtual machine ID 2AD8D389-65AE-45F7-89F8-FDF2F08CE3C2)
'******' has encountered a fatal error. The guest operating system reported that it failed with the following error codes: ErrorCode0: 0xEF, ErrorCode1: 0x11F2780, ErrorCode2: 0x0, ErrorCode3: 0x0, ErrorCode4: 0x0. If the problem persists, contact Product Support for the guest operating system. (Virtual machine ID 16A22441-2ECB-474A-8998-ECA6102DE5AC)
'******'has encountered a fatal error. The guest operating system reported that it failed with the following error codes: ErrorCode0: 0x7A, ErrorCode1: 0x119AEF8, ErrorCode2: 0xC000000E, ErrorCode3: 0x154C9860, ErrorCode4: 0x335DF592. If the problem persists, contact Product Support for the guest operating system. (Virtual machine ID A0CD6CF9-529F-4465-AD32-7A7D60069768)
The problematic VMs are with Windows OS, Windows 2008R2, Windows 2012 R2 and Windows 8.1.
My question is:
What is the cause of this problem? The event logs are not understandable at all.
How should I fix this problem?