对于RAC数据库，各个节点的归档如果放在本地，那么在使用rman进行备份或恢复管理时要配置channel各个节点，不然会因为看不到部分归档而出现错误。

一个使用channel的例子：

RMAN> show all;

RMAN configuration parameters are:

CONFIGURE RETENTION POLICY TO REDUNDANCY 1; # default

CONFIGURE BACKUP OPTIMIZATION OFF; # default

CONFIGURE DEFAULT DEVICE TYPE TO DISK; # default

CONFIGURE CONTROLFILE AUTOBACKUP OFF; # default

CONFIGURE CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE DISK TO '%F'; # default

CONFIGURE DEVICE TYPE DISK PARALLELISM 1 BACKUP TYPE TO BACKUPSET; # default

CONFIGURE DATAFILE BACKUP COPIES FOR DEVICE TYPE DISK TO 1; # default

CONFIGURE ARCHIVELOG BACKUP COPIES FOR DEVICE TYPE DISK TO 1; # default

CONFIGURE MAXSETSIZE TO UNLIMITED; # default

CONFIGURE ENCRYPTION FOR DATABASE OFF; # default

CONFIGURE ENCRYPTION ALGORITHM 'AES128'; # default

CONFIGURE ARCHIVELOG DELETION POLICY TO NONE; # default

CONFIGURE SNAPSHOT CONTROLFILE NAME TO '/oracle/app/oracle/product/10.2.0/db_1/dbs/snapcf_racdb1.f'; # default

RMAN>

run {

configure channel 1 device type disk connect 'sys/oracle@racdb1';

configure channel 2 device type disk connect 'sys/oracle@racdb2';

crosscheck archivelog all;

configure channel 1 device type disk clear;

configure channel 2 device type disk clear;

}

在测试过程中报错：

old RMAN configuration parameters:

CONFIGURE CHANNEL 1 DEVICE TYPE DISK CONNECT 'sys/oracle@RACDB1';

new RMAN configuration parameters:

CONFIGURE CHANNEL 1 DEVICE TYPE DISK CONNECT 'sys/oracle@RACDB1';

new RMAN configuration parameters are successfully stored

old RMAN configuration parameters:

CONFIGURE CHANNEL 2 DEVICE TYPE DISK CONNECT 'sys/oracle@RACDB2';

new RMAN configuration parameters:

CONFIGURE CHANNEL 2 DEVICE TYPE DISK CONNECT 'sys/oracle@RACDB2';

new RMAN configuration parameters are successfully stored

configuration for DISK channel 2 is ignored

allocated channel: ORA_DISK_1

channel ORA_DISK_1: sid=144 instance=racdb1 devtype=DISK

validation succeeded for archived log

archive log filename=/oracle/app/arch1/1_15_788564441.dbf recid=19 stamp=807982646

validation failed for archived log

archive log filename=/oracle/app/arch2/2_14_788564441.dbf recid=18 stamp=807982635

Crosschecked 2 objects

chnnel 2的配置没有生效，没有节点2的归档还是看不到。为什么呢？

Caution: Compressed Backup is CPU bound, so number of channels should be carefully used.

修改rman的配置即可：

RMAN> CONFIGURE DEVICE TYPE DISK BACKUP TYPE TO COMPRESSED BACKUPSET PARALLELISM 2;