建立STANDBY数据库时在ASM上恢复主库的数据文件出现ORA-15173错误

建立STANDBY数据库时，在ASM上恢复主库的数据文件出现了ORA-15173错误。

主库和备库都是单实例数据库，不过都使用ASM作为存储方式。

在备库上利用主库的备份进行restore database操作，碰到了这个错误：

[oracle@localhost data]$ rman target /

Recovery Manager: Release 10.2.0.3.0 - Production on Sat Feb 12 14:43:29 2011

connected to target database: MOBILEDB (DBID=3009911466, not open)

RMAN> restore database;

Starting restore at 12-FEB-11

using target database control file instead of recovery catalog

allocated channel: ORA_DISK_1

channel ORA_DISK_1: sid=1086 devtype=DISK

file 22 is excluded from whole database backup

file 25 is excluded from whole database backup

file 28 is excluded from whole database backup

file 30 is excluded from whole database backup

channel ORA_DISK_1: starting datafile backupset restore

channel ORA_DISK_1: specifying datafile(s) to restore from backup set

restoring datafile 00001 to +ORADG/mobiledb/datafile/system.260.649168943

restoring datafile 00002 to +ORADG/mobiledb/datafile/undotbs1.261.649168949

restoring datafile 00003 to +ORADG/mobiledb/datafile/sysaux.262.649168951

restoring datafile 00004 to +ORADG/mobiledb/datafile/users.264.649168953

restoring datafile 00005 to +ORAG2/mobiledb/datafile/club_stat.dbf

restoring datafile 00006 to +ORAG2/mobiledb/datafile/club_statindx.dbf

restoring datafile 00068 to +ORADG/mobiledb/datafile/users.328.652899937

channel ORA_DISK_1: reading from backup piece /rman_backup/data/df_MOBILEDB_5042_1_1

ORA-19870: error reading backup piece /rman_backup/data/df_MOBILEDB_5042_1_1

ORA-19504: failed to create file "+ORAG2/mobiledb/datafile/club_stat.dbf"

ORA-17502: ksfdcre:4 Failed to create file +ORAG2/mobiledb/datafile/club_stat.dbf

ORA-15173: entry 'mobiledb' does not exist in directory '/'

failover to previous backup

creating datafile fno=1 name=+ORADG/mobiledb/datafile/system.260.649168943

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

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

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

RMAN-03002: failure of restore command at 02/12/2011 14:50:44

ORA-01180: can not create datafile 1

ORA-01110: data file 1: '+ORADG/mobiledb/datafile/system.260.649168943'

导致这个错误的原因是RESTORE操作不会自动创建非数据库所属的目录，虽然根据控制文件中存储的位置，控制文件应该恢复到mobiledb目录中，但是由于standby数据库和primary数据库的db_unique_name并不相同，因此实际RESTORE之后，数据文件会放在standby数据库db_unique_name对应的名称MOBILEDB_N目录下，对于MOBILEDB_N目录以及其下的DATAFILE、ONLINELOG等目录，RESTORE操作会自动创建，但是mobiledb及其下的目录，RESTORE并不会自动创建，即使这个目录并不会写入内容。

解决方法也很简单，只需要通过asmcmd手工创建对应的目录结构即可：

[oracle@localhost ~]$ export ORACLE_SID=+ASM

[oracle@localhost ~]$ asmcmd

ASMCMD> cd +oradg

ASMCMD> mkdir mobiledb

ASMCMD> cd mobiledb

ASMCMD> mkdir datafile

ASMCMD> ls

datafile/

ASMCMD> cd ..

ASMCMD> ls

MOBILEDB_N/

mobiledb/

ASMCMD> cd +orag2

ASMCMD> mkdir mobiledb

ASMCMD> cd mobiledb

ASMCMD> mkdir datafile

ASMCMD> exit

再次运行RESTORE DATABASE命令，问题解决。