I have three Gen 2 VM, all running Windows Server 2012 R2 Std, performing scheduled Windows backup to NAS via iSCSI and all are reporting the following event during backup:
Log Name: Microsoft-Windows-Backup
Source: Microsoft-Windows-Backup
Date: 2/07/2014 7:01:31 AM
Event ID: 24
Task Category: None
Level: Information
Keywords:
User: SYSTEM
Computer: SVR03.server.local
Description:
Backup started a fresh backup for volume '{00000000-0000-0000-0000-000000000000}' ('Esp') : [Reason: 'Volume size changed']. This may cause loss of older backup versions when backup completes.
Event Xml:
<Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event">
<System>
<Provider Name="Microsoft-Windows-Backup" Guid="{1DB28F2E-8F80-4027-8C5A-A11F7F10F62D}" />
<EventID>24</EventID>
<Version>0</Version>
<Level>4</Level>
<Task>0</Task>
<Opcode>0</Opcode>
<Keywords>0x4000000000000000</Keywords>
<TimeCreated SystemTime="2014-07-01T21:01:31.237292800Z" />
<EventRecordID>18</EventRecordID>
<Correlation />
<Execution ProcessID="64584" ThreadID="59024" />
<Channel>Microsoft-Windows-Backup</Channel>
<Computer>SVR03.server.local</Computer>
<Security UserID="S-1-5-18" />
</System>
<EventData>
<Data Name="VolumeGUID">{00000000-0000-0000-0000-000000000000}</Data>
<Data Name="VolumeFriendlyName">Esp</Data>
<Data Name="VhdDeleteReason">Volume size changed</Data>
</EventData>
</Event>
There has been no explicit volume size change, however these VM all use Dynamically expanding virtual hard disk (VDHX).
A forth VM (Gen 1) running Windows 7 Pro, also provisioned with a Dynamically expanding virtual hard disk does not exhibit this behaviour when it performs a Windows backup.
How can I rectify this situation?
TIA
Troy