Analysis Services Won't Start - Invalid Data Directory.

MSSQLServerOLAPService File system error: Error occurred during the creation of directory.
This can be really annoying. You are trying to start Analysis Services service, but it refuses to start and you either don't know why, or you now know realise that you have updated the data directory and it doesn't exist. But how do you change it now that Analysis Services won't start?
This can happen when you change the data directory for Analysis Services to an invalid directory, or the drive is not available. An invalid drive includes a root directory drive. You really need to create a directory for Analysis Services and ensure that the service has read/write access rights to that directory.
The solution is relatively simple. Simply find the msmdsrv.ini file (it is typically in a directory like C:\Program Files\Microsoft SQL Server\MSSQL.2\OLAP\Config. Edit the file using notepad and change the DataDir value to what it should be. Analysis Services should start up now.
Having said that, I do encourage people to set the data and temp directories for Analysis Services to appropriate directories. On a large OLAP server, you really want to have these directories on fast disk subsystems. The temp directory, in particular, can incur large volumes of read/write activity when processing a large cube.

Richard
http://richardlees.com.au/