ORA-19914: unable to encrypt backup ORA-28365: wallet is not open -TDE Password-based keystore

[oracle@srv1 admin]$ sqlplus / as sysdba

SQL*Plus: Release 12.1.0.2.0 Production on Thu Aug 1 16:28:15 2019

Copyright (c) 1982, 2014, Oracle.  All rights reserved.

Connected to:

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

With the Partitioning, OLAP, Advanced Analytics and Real Application Testing options

SQL> shut immediate;

Database closed.

Database dismounted.

ORACLE instance shut down.

SQL> STARTUP

ORACLE instance started.

Total System Global Area 1795162112 bytes

Fixed Size                  2925456 bytes

Variable Size             553651312 bytes

Database Buffers         1224736768 bytes

Redo Buffers               13848576 bytes

Database mounted.

Database opened.

SQL>

SQL> SELECT KEY_ID FROM V$ENCRYPTION_KEYS;

no rows selected

[oracle@srv1 admin]$ rman target /

Recovery Manager: Release 12.1.0.2.0 - Production on Thu Aug 1 16:30:41 2019

Copyright (c) 1982, 2014, Oracle and/or its affiliates.  All rights reserved.

connected to target database: SMR1 (DBID=3409868754)

RMAN> SET ENCRYPTION ON;

executing command: SET encryption

using target database control file instead of recovery catalog

RMAN> BACKUP TABLESPACE users TAG 'ENCRYPTED_USERS';

Starting backup at 01-AUG-19

allocated channel: ORA_DISK_1

channel ORA_DISK_1: SID=63 device type=DISK

channel ORA_DISK_1: starting full datafile backup set

channel ORA_DISK_1: specifying datafile(s) in backup set

input datafile file number=00006 name=/u01/app/oracle/oradata/smr1/users01.dbf

channel ORA_DISK_1: starting piece 1 at 01-AUG-19

RMAN-00571: ===========================================================

RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============

RMAN-00571: ===========================================================

RMAN-03009: failure of backup command on ORA_DISK_1 channel at 08/01/2019 16:30:58

ORA-19914: unable to encrypt backup

ORA-28365: wallet is not open

RMAN>

RMAN> sql 'ADMINISTER KEY MANAGEMENT SET KEYSTORE OPEN IDENTIFIED BY oracle';

sql statement: ADMINISTER KEY MANAGEMENT SET KEYSTORE OPEN IDENTIFIED BY oracle

RMAN> SET ENCRYPTION ON;

executing command: SET encryption

RMAN> BACKUP TABLESPACE users TAG 'ENCRYPTED_USERS';

Starting backup at 01-AUG-19

using channel ORA_DISK_1

channel ORA_DISK_1: starting full datafile backup set

channel ORA_DISK_1: specifying datafile(s) in backup set

input datafile file number=00006 name=/u01/app/oracle/oradata/smr1/users01.dbf

channel ORA_DISK_1: starting piece 1 at 01-AUG-19

channel ORA_DISK_1: finished piece 1 at 01-AUG-19

piece handle=/u01/app/oracle/fast_recovery_area/SMR1/backupset/2019_08_01/o1_mf_nnndf_ENCRYPTED_USERS_gn5kxhcv_.bkp tag=ENCRYPTED_USERS comment=NONE

channel ORA_DISK_1: backup set complete, elapsed time: 00:00:01

Finished backup at 01-AUG-19

RMAN>