Sql Server 2016 Cannot drop database (it is really, really, really stuck) I have a database that was involved in a mirroring session and something crashed hard and the database is stuck 'in recovery' and will not allow me to drop it because it thinks the database is in use although I can't see what.

I run this and the affected database is not listed:

SELECT DB_NAME(dbid) as 'DBName'
     , loginame as 'Login'
     , COUNT(dbid) as 'Connections' 
FROM sys.sysprocesses 
WHERE dbid &gt; 0 
GROUP BY dbid, loginame


I also run EXEC sp_who2 and the database is not listed either

I run

ALTER database careplans set offline with ROLLBACK IMMEDIATE;
DROP database careplans;


and I get an error "ALTER DATABASE failed because a lock could not be placed on database 'careplans'. Try again later."

This brings back no results: 

select * from sys.sysprocesses where dbid = DB_ID( 'careplans')


This gives me the 'lock could not be placed' error:

ALTER DATABASE careplans
SET SINGLE_USER 
WITH ROLLBACK IMMEDIATE;


This gives me an "Exclusive access could not be obtained because the database is in use." error:

RESTORE DATABASE CarePlans WITH RECOVERY


Any of the following give me the 'lock could not be placed' error:

ALTER DATABASE careplans SET  SINGLE_USER WITH NO_WAIT 
ALTER DATABASE careplans SET EMERGENCY; 
DBCC CHECKDB (careplans, REPAIR_ALLOW_DATA_LOSS) 
ALTER DATABASE careplans SET online; 
ALTER DATABASE careplans SET  Multi_USER WITH NO_WAIT


I have no idea what else I can try...?
This issue is pretty tricky to reproduce so I can suggest to try two more solutions, but both require SQL Server to be restarted:


Start SQL Server in single user mode (https://docs.microsoft.com/en-us/sql/database-engine/configure-windows/start-sql-server-in-single-user-mode)
(just add SQL Server service startup parameter -m and restart the service). Then using SQL CMD connect to the SQL instance using local administrator account and try to drop database using DROP DATABASE statement. Perhaps this time you won't get an error related to exclusive access acquisition. 
Another way (pretty primitive I know! But it might be effective either!) is to stop SQL service and delete (or change location) of database files. Then when you start SQL Server back this database should come up in 'recovery pending' status and you should be able to remove it.