I got an email the other day that someone was getting an error on one of the lower MDS environments. I logged into Master Data Manager and got this message:
It appeared to be impacting all of the models and entities in the repository. The subscription views were available and data was there, but at this point the entities were all read-only.
I then got this message:
“The operating system returned error 21(The device is not ready.) to SQL Server during a read at offset 0x… in file ‘T:\MSSQL\DATA\tempdb.mdf’. Additional messages in the SQL Server error log and system event log may provide more detail. This is a severe system-level error condition that threatens database integrity and must be corrected immediately. Complete a full database consistency check (DBCC CHECKDB). This error can be caused by many factors; for more information, see SQL Server Books Online.”
Luckily this was easily resolved. There was something wrong with the tempdb and the SQL Server instance needed to be restarted. MDS was working correctly once the server was brought back up.