SQL SERVER – Fix: The operating system returned error 21(The device is not ready.)


 

The other day, I received an email from my client of Comprehensive Database Performance Health Check. The client was in very much panic as they were getting the following error – The operating system returned error 21(The device is not ready.)

The operating system returned error 21

Here is the complete description of the error on the screen.

The operating system returned error 21(The device is not ready.) to SQL Server during a read at offset 0x00000004e92000 in file ‘D:dataAdventureWorks.mdf’. Additional messages in the SQL Server error log and operating system error log may provide more detail. This is a severe system-level error