Connected to an idle instance

Hello,

Before I ask my question I want to provide some information on my environment:

Oracle Database 12c Standard Edition Release 12.1.0.2.0 - 64bit Production

With the Real Application Clusters and Automatic Storage Management options

System name:    Linux

Release:        3.8.13-118.14.2.el7uek.x86_64

Version:        #2 SMP Fri Nov 18 10:30:09 PST 2016

Machine:        x86_64

I can't connect to either production or test database via sqlplus. The result of each try (sqlplus "/ as sysdba") ended up displaying the same information about an idle instance.

0. set | grep ORA

OLD_ORACLE_BASE=

ORABASE_EXEC=/oracle/xxx/12.1.0/dbhome_1/bin/orabase

ORACLE_BASE=/oracle

ORACLE_HOME=/oracle/xxx/12.1.0/dbhome_1

ORACLE_SID=test