File system error: The following error occurred while opening the file \?MDTempStore_***_***_***.tmp: Access is denied

While working on a recent TFS Analysis Service Database migration scenario, we encountered the following scenario:

  • You try to open the properties dialog box from SSMS, for the connected SSAS instance (right click on the SSAS instance, choose properties)
  • You get the following error message:

File system error: The following error occurred while opening the

file \\?\<mount point on a network share>\MDTempStore_***_***_***.tmp: Access is denied,.

Error in the metadata manager. An error occurred when loading the Tem System cube, from the

file  \"\?\<mount point on a network share>\Tfs_Analysis.0.db\Team System.*.cub.xml",

(Microsoft.AnalysisServices)

 

To resolve the issue, we took the following steps:

  • First we created the data folder structure (along with Temp and Log folder structure) on the shared drive (on the mount point drive) i.e. T:\OLAP\data, T:\OLAP\Log, T;|OLAP\Temp etc. We then updated the msmdsrv.ini file with the Data, Log, Temp folder information
  • We recreated the Tfs_Analysis SSAS database, issuing the creation step from TFS Manager. This is to clean up.
  • We then added the user (SSAS Service Account) to the SSAS instance level security, as an Admin to SSAS. This actually made the difference, along with the clean data folder structure
  • Now, when we issue the processing command, we do not get "Access Denied" error message any more

SSAS does need sufficient read and write access to any location, it writes/reads the data along with the temporary files it needs to create, during DB creation, processing etc. We can likely take process monitor log to look at the path it tries to go to and also the file it tries to create. SSAS Service account is the one that tries to get access to on the Data/Log/Temp locations, as part of its activities. If it does not have proper permission, we may see problem.

 

Happy troubleshooting....