SQL Server Log: DeviceIoControl failed, error 21

This morning in log report of one of our production server I found an unusual  error.

DeviceIoControl failed, error 21

DeviceIOControl is a function which sends code to your disk drivers to perform read or writes functions and error 21 clearly indicates that device which we have specified to perform a job is not ready.

This happened because, on our production server, we had configured a backup job which takes daily full backup to a removable device and unfortunately it was removed by our systems department, which caused this error.

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Read More about SQL Server Log Errors/Messages 

• SQL Server has encountered 1 occurrence(s) of cachestore flush
• This instance of SQL Server has been using a process ID of xxxx since mm/dd/yyyy
• SQL Server has encountered occurrence(s) of I/O requests taking longer than 15 seconds to complete
• The time stamp counter of CPU on scheduler id 13 is not synchronized with other CPUs.
• I/O is frozen on database DatabaseName