Automatic Diagnostic Repository

转载自

http://www.eygle.com/archives/2007/08/11g_auto_diag_repository.html#comments

Oracle Database 11g的FDI（Fault Diagnosability Infrastructure）是自动化诊断方面的又一增强。
FDI的一个关键组件是自动诊断库（Automatic Diagnostic Repository-ADR）。

在Oracle Database 11g之前，Oracle的各类跟踪文件、日志文件等诊断文件的存储位置并不统一，现在在FDI的基础架构之上，Oracle开始统一规划这些文件的存储，ADR之于诊断文件，就类似于OFA（Optimal Flexible Architecture ）之于数据库文件，FRA（Flash Recovery Area）之于备份文件。

ADR的路径被称为ADR BASE，这个位置由一个新的初始化参数DIAGNOSTIC_DEST决定。

SQL> show parameter diagnostic_dest

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
diagnostic_dest                      string      /opt/oracle

这个参数的缺省值和环境变量ORACLE_BASE有关：
■ 如果设置了 ORACLE_BASE 则 DIAGNOSTIC_DEST = ORACLE_BASE
■ 如果未设置 ORACLE_BASE ，则 DIAGNOSTIC_DEST = ORACLE_HOME/log

我们可以简单看一下ADR BASE的目录结构：

[oracle@test126 ~]$ tree -d diag/
diag/
|-- asm
|-- clients
|-- crs
|-- diagtool
|-- lsnrctl
|-- netcman
|-- ofm
|-- rdbms
|   `-- eygle
|       `-- eygle
|           |-- alert
|           |-- cdump
|           |-- hm
|           |-- incident
|           |-- incpkg
|           |-- ir
|           |-- lck
|           |-- metadata
|           |-- stage
|           |-- sweep
|           `-- trace
`-- tnslsnr
    `-- test126
        `-- listener
            |-- alert
            |-- cdump
            |-- incident
            |-- incpkg
            |-- lck
            |-- metadata
            |-- stage
            |-- sweep
            `-- trace

33 directories

现在一目了然，包括ASM、CRS等组件日志都被ADR囊括其中。

对于FRA，通过V$FLASH_RECOVERY_AREA_USAGE视图，Oracle可以知道闪回区的使用情况.
现在对于ADR，Oracle可以通过一个新的视图v$diag_info来查询自动诊断库的信息：

SQL> select * from v$diag_info;

   INST_ID NAME                      VALUE
---------- ------------------------- ------------------------------------------------------------
         1 Diag Enabled              TRUE
         1 ADR Base                  /opt/oracle
         1 ADR Home                  /opt/oracle/diag/rdbms/eygle/eygle
         1 Diag Trace                /opt/oracle/diag/rdbms/eygle/eygle/trace
         1 Diag Alert                /opt/oracle/diag/rdbms/eygle/eygle/alert
         1 Diag Incident             /opt/oracle/diag/rdbms/eygle/eygle/incident
         1 Diag Cdump                /opt/oracle/diag/rdbms/eygle/eygle/cdump
         1 Health Monitor            /opt/oracle/diag/rdbms/eygle/eygle/hm
         1 Default Trace File        /opt/oracle/diag/rdbms/eygle/eygle/trace/eygle_ora_10858.trc
         1 Active Problem Count      0
         1 Active Incident Count     0

11 rows selected.

SQL> select table_name from dict where table_name like '%DIAG%';

TABLE_NAME
------------------------------
V$DIAG_INFO
GV$DIAG_INFO

============================================================================================

10.Consider the following scenario for your database: 
-Backup optimization is enabled in RMAN. The recovery window is set to 7 days in RMAN. The most 
recent backup to disk for the TOOLS tablespace was taken on November 3, 2007. 
The TOOLS tablespace is read-only since November 4, 2007. 
On November 23, 2007, you issue the RMAN command to back up the database to disk. Which statement 
is true regarding the backup of the TOOLS tablespace? 
A. The RMAN backup fails because the TOOLS tablespace is read-only 
B. The RMAN skips the backup of the tablespace because backup optimization is enabled 
C. The RMAN makes backup because optimization can be enabled only for backups to disk 
D. The RMAN makes the backup because no backup of the tablespace exists within the seven day 
window 
Answer: D 
解析: 
Suppose that backup optimization is enabled, and a recovery window backup retention policy is in effect. In this case, when performing SBT backups RMAN always backs up datafiles whose most recent backup is older than the recovery window. For example, assume the following scenario:

1. Today is February 21. 
2. The recovery window is 7 days. 
3. The most recent backup of tablespace tools to tape is January 3. 
4. Tablespace tools is read-only. 
On February 21, when you issue a command to back up tablespace tools to tape, RMAN backs it up even though it did not change after the January 3 backup (because it is read-only). RMAN makes the backup because no backup of the tablespace exists within the 7-day recovery window.

This behavior enables the media manager to expire old tapes. Otherwise, the media manager would be forced to keep the January 3 backup of tablespace tools indefinitely. By making a more recent backup of tablespace tools on February 21, RMAN enables the media manager to expire the tape containing the January 3 backup.

参考: 
http://docs.oracle.com/cd/B28359_01/backup.111/b28270/rcmconfb.htm#BRADV89437