Vmmaxsnapshotretry

During a VM backup, if a snapshot of a VM fails due to a temporary condition, Data Protection for Microsoft Hyper-V automatically retries the snapshot operation up to the number of times that is specified by the vmmaxsnapshotretry option. If the snapshot still fails after the maximum number of retries is reached, the snapshot operation for the VM is not retried and the backup attempt fails.

For example, a recoverable condition might be caused by two backup requests that started at about the same time, backing up VMs that reside on the same volume. One backup operation reports that the snapshot failed because the backup cannot be started while another backup is running for the same VM. In this case, Data Protection for Microsoft Hyper-V will retry the snapshot operation after the first VM backup is completed.

If the initial error is not recoverable, a snapshot is not attempted. For example, if an error occurs with the Volume Shadow Copy Services (VSS) writer during the initial snapshot process, the backup processing stops and Data Protection for Microsoft Hyper-V does not retry the snapshot operation.

This option is valid only for Hyper-V backup operations on Windows Server 2012 and 2012 R2 operating systems.

Supported clients

This option is valid for all supported Windows clients. This option can also be defined on the server.

Options file

This option is valid in the client options file (dsm.opt) or on the command line for the Backup VM command. It can also be included on the server in a client option set. It cannot be set in the Preferences Editor.

Syntax

                       .-20------.   
>>-VMMAXSNApshotretry--+-integer-+-----------------------------><

Parameters

integer

Specifies the maximum number of times to retry the snapshot operation of a VM if the initial snapshot attempt fails with a recoverable condition. The default is 20. The maximum is 30. The minimum is 1.

For example, if the vmmaxsnapshotretry option is set to 12, Data Protection for Microsoft Hyper-V retries the snapshot operation up to 12 times after the initial snapshot failed during a VM backup operation. If the snapshot still fails after 12 retries are reached, no more retries are attempted, and the backup attempt fails.

At least 10 minutes must elapse before the next snapshot retry attempt. The time between attempts will be longer when the failed VM is part of a snapshot with VMs that are currently being backed up. The backup operation of the other VMs must be completed and the snapshot is removed by the backup operation before a retry attempt can be made.