从oracle 12c开始提供了rman通过from service方式搭建dg,使用12c长期支持版19c(并打上最新的patch)
配置dataguard相关参数

alter system set db_unique_name='XIFENFEI' scope=spfile;
alter system set service_names='XIFENFEI';
alter system set log_archive_config='dg_config=(XIFENFEI,XIFENFEIDG)';
alter system set log_archive_dest_1='LOCATION=USE_DB_RECOVERY_FILE_DEST valid_for=(all_logfiles,all_roles) db_unique_name=XIFENFEI';
alter system set log_archive_dest_2='service=XIFENFEIDG lgwr async valid_for=(online_logfiles,primary_role) db_unique_name=XIFENFEIDG';
alter system set standby_file_management=auto;
alter system set db_file_name_convert='/u01/app/oracle/oradata/XIFENFEI/','/u01/app/oracle/oradata/XIFENFEI/' scope=spfile;
alter system set log_file_name_convert='/u01/app/oracle/oradata/XIFENFEI/','/u01/app/oracle/oradata/XIFENFEI/' scope=spfile;
alter system set fal_server=XIFENFEIDG;

配置tnsnames.ora

XIFENFEI =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.0.238)(PORT = 1521))
    )
    (CONNECT_DATA =
      (SERVICE_NAME = XIFENFEI)
    )
  )

XIFENFEIDG =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.0.124)(PORT = 1521))
    )
    (CONNECT_DATA =
      (SERVICE_NAME = XIFENFEI)
    )
  )

拷贝主库密码文件到备库

[oracle@primary ~]$ scp $ORACLE_HOME/dbs/orapwXIFENFEI 192.168.0.124:$ORACLE_HOME/dbs/
The authenticity of host '192.168.0.124 (192.168.0.124)' can't be established.
ECDSA key fingerprint is SHA256:NI2952z4Bqc3M/B+AK7EJRiJNauROIyluvu1l4NSTX0.
ECDSA key fingerprint is MD5:1d:64:dd:ef:1c:ad:ed:cf:70:22:2d:4d:7c:90:5e:5e.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '192.168.0.124' (ECDSA) to the list of known hosts.
oracle@192.168.0.124's password: 
orapwXIFENFEI                                                                   100% 2048     6.6MB/s   00:00    
[oracle@primary ~]$ 

备库启动到nomount状态

[oracle@standby ~]$ sqlplus / as sysdba

SQL*Plus: Release 19.0.0.0.0 - Production on Sat Mar 13 20:32:34 2021
Version 19.10.0.0.0

Copyright (c) 1982, 2020, Oracle.  All rights reserved.

Connected to an idle instance.

SQL> create spfile from pfile='/tmp/pfile';

File created.

SQL> startup nomount pfile='/tmp/pfile'
ORACLE instance started.

Total System Global Area 4294963264 bytes
Fixed Size                  8904768 bytes
Variable Size             805306368 bytes
Database Buffers         3472883712 bytes
Redo Buffers                7868416 bytes
SQL> exit
Disconnected from Oracle Database 19c Enterprise Edition Release 19.0.0.0.0 - Production
Version 19.10.0.0.0

rman from service方式创建standby ctl和还原数据文件

[oracle@standby ~]$ rman target /

Recovery Manager: Release 19.0.0.0.0 - Production on Sat Mar 13 20:34:37 2021
Version 19.10.0.0.0

Copyright (c) 1982, 2019, Oracle and/or its affiliates.  All rights reserved.

connected to target database: XIFENFEI (not mounted)

RMAN> restore standby controlfile from service XIFENFEI;

Starting restore at 13-MAR-21
using target database control file instead of recovery catalog
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=9 device type=DISK

channel ORA_DISK_1: starting datafile backup set restore
channel ORA_DISK_1: using network backup set from service XIFENFEI
channel ORA_DISK_1: restoring control file
channel ORA_DISK_1: restore complete, elapsed time: 00:00:01
output file name=/u01/app/oracle/oradata/XIFENFEI/control01.ctl
output file name=/u01/app/oracle/fast_recovery_area/XIFENFEI/control02.ctl
Finished restore at 13-MAR-21

RMAN> alter database mount;

released channel: ORA_DISK_1
Statement processed

RMAN> restore database from service XIFENFEI;

Starting restore at 13-MAR-21
Starting implicit crosscheck backup at 13-MAR-21
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=12 device type=DISK
Finished implicit crosscheck backup at 13-MAR-21

Starting implicit crosscheck copy at 13-MAR-21
using channel ORA_DISK_1
Finished implicit crosscheck copy at 13-MAR-21

searching for all files in the recovery area
cataloging files...
no files cataloged

using channel ORA_DISK_1

channel ORA_DISK_1: starting datafile backup set restore
channel ORA_DISK_1: using network backup set from service XIFENFEI
channel ORA_DISK_1: specifying datafile(s) to restore from backup set
channel ORA_DISK_1: restoring datafile 00001 to /u01/app/oracle/oradata/XIFENFEI/system01.dbf
channel ORA_DISK_1: restore complete, elapsed time: 00:00:07
channel ORA_DISK_1: starting datafile backup set restore
channel ORA_DISK_1: using network backup set from service XIFENFEI
channel ORA_DISK_1: specifying datafile(s) to restore from backup set
channel ORA_DISK_1: restoring datafile 00003 to /u01/app/oracle/oradata/XIFENFEI/sysaux01.dbf
channel ORA_DISK_1: restore complete, elapsed time: 00:00:07
channel ORA_DISK_1: starting datafile backup set restore
channel ORA_DISK_1: using network backup set from service XIFENFEI
channel ORA_DISK_1: specifying datafile(s) to restore from backup set
channel ORA_DISK_1: restoring datafile 00004 to /u01/app/oracle/oradata/XIFENFEI/undotbs01.dbf
channel ORA_DISK_1: restore complete, elapsed time: 00:00:07
channel ORA_DISK_1: starting datafile backup set restore
channel ORA_DISK_1: using network backup set from service XIFENFEI
channel ORA_DISK_1: specifying datafile(s) to restore from backup set
channel ORA_DISK_1: restoring datafile 00007 to /u01/app/oracle/oradata/XIFENFEI/users01.dbf
channel ORA_DISK_1: restore complete, elapsed time: 00:00:01
Finished restore at 13-MAR-21
[/sehll]
备库启动mrp进程
1
1
2021-03-13T20:54:08.075418+08:00
Attempt to start background Managed Standby Recovery process (XIFENFEI)
Starting background process MRP0
2021-03-13T20:54:08.086269+08:00
MRP0 started with pid=56, OS id=8182 
2021-03-13T20:54:08.087276+08:00
Background Managed Standby Recovery process started (XIFENFEI)
2021-03-13T20:54:13.104757+08:00
 Started logmerger process
2021-03-13T20:54:13.112058+08:00

IM on ADG: Start of Empty Journal 

IM on ADG: End of Empty Journal 
PR00 (PID:8188): Managed Standby Recovery starting Real Time Apply
2021-03-13T20:54:13.205668+08:00
Parallel Media Recovery started with 4 slaves
2021-03-13T20:54:13.216576+08:00
Stopping change tracking
PR00 (PID:8188): Media Recovery Waiting for T-1.S-25 (in transit)
2021-03-13T20:54:13.269138+08:00
Recovery of Online Redo Log: Thread 1 Group 12 Seq 25 Reading mem 0
  Mem# 0: /u01/app/oracle/oradata/XIFENFEI/s_redo12.log

至此dataguard基本上搭建完成