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标题：ARCn: Media recovery disabled原因分析
作者：惜分飞©版权所有[未经本人同意,不得以任何形式转载,否则有进一步追究法律责任的权利.]
1.数据库版本
SQL> select * from v$version; BANNER ------------------------------------------------------------- Oracle9i Enterprise Edition Release 9.2.0.8.0 - Production PL/SQL Release 9.2.0.8.0 - Production CORE 9.2.0.8.0 Production TNS for Linux: Version 9.2.0.8.0 - Production NLSRTL Version 9.2.0.8.0 - Production
2.alert日志出现类此记录
Fri Feb 10 05:16:55 2012 ARC1: Media recovery disabled Fri Feb 10 05:17:23 2012 ARC0: Media recovery disabled Fri Feb 10 05:17:23 2012 ARC1: Media recovery disabled Fri Feb 10 05:18:23 2012 ARC1: Media recovery disabled Fri Feb 10 05:19:12 2012 Thread 1 advanced to log sequence 24 Current log# 1 seq# 24 mem# 0: /tmp/recover/redo01.log Fri Feb 10 05:19:12 2012 ARC0: Media recovery disabled Fri Feb 10 05:19:23 2012 ARC1: Media recovery disabled Fri Feb 10 05:20:23 2012 ARC1: Media recovery disabled Fri Feb 10 05:21:23 2012 ARC1: Media recovery disabled
3.数据库归档信息
SQL> archive log list; Database log mode No Archive Mode Automatic archival Enabled Archive destination /tmp/recover Oldest online log sequence 25 Current log sequence 27 SQL> show parameter log_archive_start NAME TYPE VALUE ------------------------------------ ----------- --------------- log_archive_start boolean TRUE
从这里可以看出，数据库处于非归档模式，但是log_archive_start=true，这样会导致归档进程自动启动(ARCn),因为数据库设置为非归档模式，从而导致该进程启动后，又自己关闭
4.解决方法
SQL> alter system set log_archive_start=false scope=spfile; System altered. SQL> startup force ORACLE instance started. Total System Global Area 202445176 bytes Fixed Size 450936 bytes Variable Size 167772160 bytes Database Buffers 33554432 bytes Redo Buffers 667648 bytes Database mounted. Database opened. SQL> show parameter log_archive_start NAME TYPE VALUE ------------------------------------ ----------- -------------- log_archive_start boolean FALSE SQL> ARCHIVE LOG LIST; Database log mode No Archive Mode Automatic archival Disabled Archive destination /tmp/recover Oldest online log sequence 26 Current log sequence 28
ALERT中无类此记录出现
ARC0: Media Recovery Disabled [ID 131119.1]
fact: Oracle Server - Enterprise Edition symptom: Alert log contains archiving error symptom: ARC0: media recovery disabled change: Added the following paramters to the init.ora with valid values to enable archiving: LOG_ARCHIVE_DEST (or LOG_ARCHIVE_DEST_n ) LOG_ARCHIVE_FORMAT LOG_ARCHIVE_START = TRUE cause: This problem occurs because an archive process has been started on a database which is running in NOARCHIVELOG mode. This happens when a database running in NOARCHIVELOG mode is started with the parameter LOG_ARCHIVE_START=TRUE. Thus an archive process is started but as the database is not in ARCHIVELOG mode, that process has no work to perform and reports the above message to the alert.log. To verify: SQL> select log_mode from v$database; /* LOG_MODE is NOARCHIVELOG */ SQL> show parameter log_archive_start; /* VALUE is TRUE */ Fix: The key to the fix is if your intend your database to be running in ARCHIVELOG or NOARCHIVELOG mode. 1. If intention is to have database in ARCHIVELOG mode: 1.1. Alter the database log mode: SQL> startup mount; SQL> alter database archivelog; 2. If intention is to have database in NOARCHIVELOG mode: 2.1. Do not start an archive process on startup: set LOG_ARCHIVE_START=FALSE (default) 2.2. Ignore message in alert.log NOTE: LOG_ARCHIVE_START initialization parameters is deprecated in Release 10.1.