RMAN-00571,RMAN-00569,RMAN-00571,RMAN-03002: failure of list command at 03/12/2019 19:26:16,RMAN-06403: could not obtain a fully authorized session,ORA-01034: ORACLE not available,ORA-27101: shared memory realm does not exist

C:\Users\ashwanik\Desktop\MY_SCRIPT>rman target /

Recovery Manager: Release 11.2.0.4.0 - Production on Tue Mar 12 19:26:11 2019

Copyright (c) 1982, 2011, Oracle and/or its affiliates.  All rights reserved.

connected to target database (not started)

RMAN> list backup
2> ;

using target database control file instead of recovery catalog
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: failure of list command at 03/12/2019 19:26:16
RMAN-06403: could not obtain a fully authorized session
ORA-01034: ORACLE not available
ORA-27101: shared memory realm does not exist

Solution: Restart the services will resolve the issue.