rman duplicate 比較重要的知識點

rman duplicate database 必須是同樣的平臺，可是支持32bit\64bit 間復制，且 在復制完畢后須要執(zhí)行$ORACLE_HOME/rdbms/admin/utlirp.sql
腳本來轉換pl/sql 代碼

The DUPLICATE command requires one or more auxiliary channels. These channels perform the work of the duplication on the auxiliary database instance.
rman duplicate 命令須要在備庫上至少要分配一個以上輔助通道（auxiliary channels）

If the source database files are in the Oracle Managed Files (OMF) format, then you cannot use the DB_FILE_NAME_CONVERT and
LOG_FILE_NAME_CONVERT initialization parameters or the fileNameConversionSpec clause to generate new OMF file names for the
duplicate database. If you do not follow this rule, the new OMF files generated from these three methods can cause problems
使用duplicate 時必需要注意，假設源庫使用OMF，那么我們就不能使用 DB_FILE_NAME_CONVERT 和 LOG_FILE_NAME_CONVERT 和其它的文件轉
換方式。否者就會出問題；比如。備庫的控制文件中的數(shù)據文件名稱是依據DB_FILE_NAME_CONVERT 和 LOG_FILE_NAME_CONVERT 轉換而來，可是實際數(shù)據文件求不在相應的路徑下，實際文件會採用OMF來管理；這時須要使用：

1》RMAN catalog 和 switch database to copy

2》alter database rename file to 和

3》switch datafile file# to copy 來修正控制文件的信息；

當然也有例外，假設僅僅是換個asm 磁盤組名，其它路徑名不變，能夠使用DB_FILE_NAME_CONVERT
The only exception to this rule is when changing only an ASM disk group name. Assume that source data files and online redo
log files are stored in ASM disk group +SOURCEDSK. You want to store the duplicate database files in ASM disk group +DUPDSK.
In this case, you can set the initialization parameters as follows:
DB_FILE_NAME_CONVERT = ("+SOURCEDSK","+DUPDSK")
LOG_FILE_NAME_CONVERT = ("+SOURCEDSK","+DUPDSK")

RMAN uses DB_FILE_NAME_CONVERT or LOG_FILE_NAME_CONVERT to convert the disk group name, and then generates a new, valid file
name based on the converted disk group name.

-假設源庫使用OMF，建議使用下面參數(shù)配置：
You have the following other supported options for naming data files when the source files are in the Oracle Managed Files format:

1.Use SET NEWNAME to specify names for individual data files.
2.Set DB_FILE_CREATE_DEST to make all data files of the new database Oracle-managed files, except the files for which SET

NEWNAME is used. You should not set DB_FILE_NAME_CONVERT if you set DB_FILE_CREATE_DEST.
DB_CREATE_FILE_DEST
DB_RECOVERY_FILE_DEST

對于redolog 假設沒有設置DB_RECOVERY_FILE_DEST, or DB_CREATE_ONLINE_LOG_DEST_n. 則會使用DB_CREATE_FILE_DEST 參數(shù)指定的文件夾來存放

SQL> show parameter DB_CREATE_ONLINE_LOG_DEST
NAME TYPE VALUE

db_create_online_log_dest_1 string
db_create_online_log_dest_2 string
db_create_online_log_dest_3 string
db_create_online_log_dest_4 string
db_create_online_log_dest_5 string
若單獨指定 db_create_online_logdest* 參數(shù)。則redolog member 會冗余放到這些單獨指定的文件夾下

Supported options for naming online redo logs duplicated from Oracle-managed files are DB_CREATE_FILE_DEST,
DB_RECOVERY_FILE_DEST, or DB_CREATE_ONLINE_LOG_DEST_n.

----DB_CREATE_ONLINE_LOG_DEST_n 參數(shù)解釋，為redolog，control file指定存放文件夾，指定多個則多路復用
DB_CREATE_ONLINE_LOG_DEST_n (where n = 1, 2, 3, ... 5) specifies the default location for Oracle-managed control files and online redo logs. If more than one DB_CREATE_ONLINE_LOG_DEST_n parameter is specified, then the control file or online redo log is multiplexed across the locations of the other DB_CREATE_ONLINE_LOG_DEST_n parameters. One member of each online redo log is created in each location, and one control file is created in each location.

Specifying at least two parameters provides greater fault tolerance for the control files and online redo logs if one of the locations should fail.

If a file system directory is specified as the default location, then the directory must already exist; Oracle does not create it. The directory must have appropriate permissions that allow Oracle to create files in it. Oracle generates unique names for the files, and a file thus created is an Oracle Managed File.
對于文件系統(tǒng)而言，指定的文件夾必須權限準確，且已經存在；假設沒有，oracle 不會自己主動創(chuàng)建
注意:nofilenamecheck參數(shù)需要解釋下:
如果在復制時，位置不同時，我們會用參數(shù)db_file_name_convert 對文件位置進行轉換。 但是如果在復制時我們用的是相同的位置。 這里必須加上nofilenamecheck參數(shù)。 該參數(shù)通知復制操作不必在執(zhí)行還原操作前確認文件名是不同的。如果沒有指定nofilenamecheck參數(shù)，rman會給出如下錯誤：
RMAN-05001: auxiliary filename /DBSoft/oracle/oradata/woo/users01.dbf conflicts with a file used by the target database