RMAN-06820 ORA-17629

– RMAN备份归档报错，日志如下：

RMAN> connect target *
2> run {
3> ALLOCATE CHANNEL a1 TYPE 'SBT_TAPE';
4> ALLOCATE CHANNEL a2 TYPE 'SBT_TAPE';
6> BACKUP SKIP INACCESSIBLE filesperset 20 format '%s_%p_%T' not backed up 1 times archivelog all;
10> RELEASE CHANNEL a1;
11> RELEASE CHANNEL a2;
12> }
...
Starting backup at 28-OCT-21
RMAN-06820: WARNING: failed to archive current log at primary database
ORACLE error from target database: 
ORA-17629: Cannot connect to the remote database server
ORA-17627: ORA-12154: TNS:could not resolve the connect identifier specified
ORA-17629: Cannot connect to the remote database server

根据MOS文档(Doc ID 2025142.1)：原因是不能通过DG配置的监听连接到主库切换日志

1 检查DG配置和tnsnames配置：发现DG_CONFIG配置的service并没有在tnsnames.ora文件中

-- 在备库中添加parameter中dg_config中配置的service
orcldg = (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=*.*.*.*)(PORT=1521))(CONNECT_DATA=(SERVER=DEDICATED)(SERVICE_NAME=orcldg)))
orcl   = (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=*.*.*.*)(PORT=1521))(CONNECT_DATA=(SERVER=DEDICATED)(SERVICE_NAME=orcl)))

2 配置之后按照Doc 2025142.1 备份归档并生产RMAN trace，并没有发现再报错
-- 如果不知道sys密码，需要重置并重新和所有主备节点同步一下
-- 在ADG上执行一次备份归档，生成RMAN的trace  测试备份并没有报错
rman target sys/password@orcldg debug trace=/tmp/rmandebug.trc log=/tmp/rmanlog.trc
run {
ALLOCATE CHANNEL a1 TYPE DISK;
backup archivelog sequence 1832  format '/tmp/rman_rch_1832.bk';
RELEASE CHANNEL a1;
}

总结：
参数dg_config是虽然可以配置和archive_dest中使用的service不一样，dg_config中的配置也可以不在tnsnames.ora中配置，DG也能正常搭起来。
但是，在要用到dg_config中配置的参数的场景的时候，就会报错。

RMAN-06820 ORA-17629 ORA-12154 During Backup of a Standby Database (Doc ID 2025142.1)

SYMPTOMS
While taking the backup from standby db, the below error is returned:
 
RMAN> connect target sys/passwd@tns_standby

RMAN-06009: using target database control file instead of recovery catalogRMAN-08030: allocated channel: ch1
RMAN-08500: channel ch1: SID=70 device type=SBT_TAPE
RMAN-08526: channel ch1: CommVault Systems for Oracle: Version 9.0.0(BUILD84)

RMAN-03090: Starting backup at 25-JUN-15
RMAN-06820: WARNING: failed to archive current log at primary database
RMAN-06003: ORACLE error from target database:
ORA-17629: Cannot connect to the remote database server
ORA-17627: ORA-12154: TNS:could not resolve the connect identifier specified
ORA-17629: Cannot connect to the remote database server

CHANGES
Sqlnet configuration has been modified. For example, entries in the tnsnames.ora file were removed in the standby server. 

CAUSE
Sqlnet configuration modifications preventing RMAN from connecting to the primary database to switch online logs.  This is new functionality in 11.2.0.4 and beyond.   
In this example, a removal of TNS entry in the standby used by RMAN is missing.

SOLUTION
1. Generate RMAN trace as below:
$ rman target sys/passwd@tns_standby debug trace=/tmp/rmanDebug_new.trc log=/tmp/rmanLog_new.txt

RMAN> Run the backup script

Rman trace file:
DBGSQL: B :primary_dbuname = chlbbkof2
DBGSQL: B :lprimary_db_cs = <service_name2> =============================> RMAN is using the service name "<service_name2>" to connect to the primary database to perform the log switch.
DBGSQL: error: ORA-17629: Cannot connect to the remote database server (krmkosqlerr)
DBGSQL: ORA-17627: ORA-12154: TNS:could not resolve the connect identifier specified (krmkosqlerr)
DBGSQL: ORA-17629: Cannot connect to the remote database server (krmkosqlerr)
DBGSQL: ORA-06512: at "SYS.X$DBMS_BACKUP_RESTORE", line 7812 (krmkosqlerr)

2. Search for the string "lprimary_db_cs" in the trace file:
DBGSQL:             B :lprimary_db_cs = <service_name2>

3. Add the corresponding entry in the tnsnames.ora file of standby database which should be able to ping to primary as below:
service_name2 =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = <primary_host>.com)(PORT = 1521))
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME =service_name2)
    )
  )

4.  If entry exists, test the connection.  From standby server, execute:
$  sqlplus 'sys/password@<service name found in #2> as sysdba' 
搭建DG的时候，也需要在主库和备库测试是否能通过service_name连接到主库和备库