On Exchange servers, this is a variation on “Writer's state. If a particular writer has a very large number of associated files, it is probably the culprit. The output file will contain a list of files associated with each writer. To identify the writer that’s spending too much time enumerating files, collect the logs in KB1789 and provide them when opening a technical support case.Īlternatively, use the Diskshadow utility from an administrator command prompt within the VM guest OS: Unusual search scopes have also sometimes been implicated. For more info see Potential issues after installing SharePoint Foundation 2010 SP1. On SharePoint servers, you may need to run PSCONFIG. Compare the dates on the transaction logs to the date of the last successful Veeam backup to verify transaction logs are being truncated correctly. You can increase the timeout or truncate the logs by another method. On Exchange servers, this error typically indicates a large number of transaction logs. The timeout can be extended to several hours. Stop any running jobs or wait for them to complete, then restart the Veeam Backup Service.Ĭertain configurations (such as MS SQL Server with FILESTREAM) or third-party VSS writers may require significant time for preparation. This will change the timeout to 30 minutes. The value is in milliseconds (decimal), the default timeout is 900000, which equals 15 minutes. Go to registry key HKEY_LOCAL_MACHINE\SOFTWARE\Veeam\Veeam Backup and ReplicationĪdd a DWORD (32-bit) value named VssPreparationTimeout. You can change this timeout by modifying the value in the registry of the server where Veeam Backup & Replication is installed as follows: “VSSControl: Failed to prepare guest for freeze, wait timeout 900 sec." Otherwise, consult the relevant section below: Improving in-guest performance will help in resolving either error. Return of snapshot information via VIM API2ġ If a network connection to the guest OS is not available, VIX API will be used, which introduces additional latency.Ģ These steps should usually be near-instantaneous, but if the vCenter is heavily loaded or has a high latency to the ESXi hosts, the delay may be significant. VSS will only hold a freeze on the writers for up to 60 seconds (20 for Exchange), so several steps must fit within this timeframe:
Veeam uses VSS to freeze applications immediately prior to creating the VMware snapshot, and then sends the thaw command as soon as snapshot creation is complete.
"VSSControl: Failed to freeze guest, wait timeout" refers to the limit imposed by Microsoft VSS writers on the duration of a freeze. The timeout may be exceeded because of performance limitations of the VM guest, or because a specific writer is enumerating a very large number of files. "VSSControl: Failed to prepare guest for freeze, wait timeout 900 sec" refers to VSS preparation, which consists largely of enumerating VSS writers, their components, and associated files and volumes. These errors look similar but their causes are unrelated. "VSSControl: Failed to freeze guest, wait timeout" "VSSControl: Failed to prepare guest for freeze, wait timeout 900 sec." "VSSControl: Failed to prepare guest for freeze, wait timeout 900 secĮither of the following errors occurs in the job statistics: