SQL Server Error “Database 'mssqlsystemresource' does not exist.”

Question

On Linux, whenever I run use mssqlsystemresource to get access to Resource Database, I get an error. How do I resolve this.

1> use mssqlsystemresource
2> go
Msg 911, Level 16, State 1, Server x230, Line 1
Database 'mssqlsystemresource' does not exist. Make sure that the name is entered correctly.

When I try to log in with sqlcmd with DAC (admin:) targeting the database with -d

$ sqlcmd -I -S admin:localhost -U sa -d mssqlsystemresource -P Password0
Sqlcmd: Error: Microsoft ODBC Driver 13 for SQL Server : Cannot open database "mssqlsystemresource" requested by the login. The login failed..
Sqlcmd: Error: Microsoft ODBC Driver 13 for SQL Server : Login failed for user 'sa'..

When I try to log in with mssql-cli's -A, I get

$ mssql-cli -A -d mssqlsystemresource
Username (press enter for sa): 
Password: 

Connection did not succeed.
Error message: Cannot open database "mssqlsystemresource" requested by the login. The login failed.
Login failed for user 'sa'.
Unable to connect. Please try again

Answer 1

The mssqlsystemresource database is only available in single-user mode. On Linux, that means

sudo systemctl stop mssql-server
sudo -u mssql /opt/mssql/bin/sqlservr -m