Shame on me that I've overlooked "decrease" and increased the value instead
. After we decreased the value we opened a support case and last night we could finally solve the problem. We had to run a stored procedure to solve the problem. We did the following steps:
1. Configure an override to disable the maintenance procedure for the dataset:
a. Open the Ops Mgr console using the account with administrative rights. Go to the Authoring section.
b. Navigate to Rules and look for Standard Data Warehouse Data Set maintenance rule.
c. Right-click the Standard Data Warehouse Data Set maintenance rule and select Overrides > Override the Rule > For a specific object of class: Standard Data Set.
In the Override Properties window, select the check box next to the Enabled parameter, change the Override Value to False, and click Apply to save changes.
This will prevent dataset maintenance from running automatically for the given dataset type.
2. Restart the System Center Management service on the RMS to disable all running maintenance procedures.
3. Wait 10 minutes, then connect to the SQL server that hosts the Ops Mgr DW DB and open SQL Server Management Studio.
Run the following query:
DECLARE @DataSet uniqueidentifier
SET @DataSet = (SELECT DatasetId FROM StandardDataset WHERE SchemaName = 'VeeamBackupMP')
EXEC StandardDatasetMaintenance @DataSet
The query could take several hours to complete depending on how much data has been flooded to the warehouse. Do not stop the query until it completes.
4. Once the query completes, delete the override configured at step 1.
The table VeeamBackupMP.SessionTaskStaging had 1.9Mio rows and a size of 2TB in our case. The above stored procedure stopped unexpectedly several times after some hours, then we increase the Datawarehouse servers memory (and the memory allocated for the MSSQL DB) to 96GB and the procedure finished after 9 hours successfully.