Dell EMC Avamar for Windows Servers 19.7 User Guide

System State backups of offline dynamic critical disks fail in Windows Server 2008

A known problem with the ASR writer on Windows Server 2008 may cause System State backups of offline dynamic critical disks to fail. The failure may occur with an ASR writer error code (0x800423f4). If this error occurs, set the dynamic critical disks online, and rerun the backup. The error does not occur on Windows Server 2008 R2, or Windows Server 2012 or later.

Backup fails when Windows deletes the Shadow Volume during backup

Windows sometimes deletes the Shadow Volume although Avamar is running the backup service. This is a known Microsoft issue that affects all backup products. When this backup failure occurs, the Windows Event Viewer System log may contain an error similar to the following:

The shadow copies of volume H: were deleted because the shadow copy storage could not grow in time. Consider reducing the IO load on the system or choose a shadow copy storage volume that is not being shadow copied.

If this issue occurs, try one or both of the following workarounds:

• Leave more space on the drive.
• Perform the backup when the drive is less busy.

System State backups of dynamic critical volumes on storage spaces are not supported

System State backups of dynamic critical volumes on storage spaces in Windows Server 2012 fail. When storage spaces are on a dynamic critical disk, a System State backup cannot detect the storage spaces because of API incompatibility. The backup includes the storage spaces because they contain critical volumes, but you cannot restore the configuration for the storage spaces during BMR.

Use the following guidelines to ensure that backups protect both storage spaces and dynamic critical volumes:

• Do not create storage spaces on dynamic disks.
• Place dynamic critical volumes on basic disks.

Windows Server Core 2012 backup completes with exceptions

An exception may occur when backing up Windows Server Core 2012, with an error similar to the following:

Unable to open directory "c:\Users\Default\PrintHood" (code 3: The system cannot find the path specified).

To avoid the exception, add an exclude attribute and value in the plug-in options for the backup.

System State backups exclude Windows Server 2012 deduplicated volumes

Do not perform a System State backup of Windows Server 2012 deduplicated volumes if the volumes are critical volumes. Microsoft does not recommend making a deduplicated volume a critical volume, and Avamar excludes deduplicated volumes from VSS backups.