今天同事问到一个问题，他那边的一套Oracle 11g数据库使用RMAN没办法删除旧的归档，导致磁盘使用率很高。要来ip登录上去一看确实是，最旧的归档日志是16年5月的。oracle@ps251n2s:[/opt/oracle/archive/db] ls -ltr |more total 3059881082 -rw-r----- 1 oracle oinstall 725320704 May 20 2016 1_1_91233774.dbf -rw-rw---- 1 oracle oinstall 1756937216 Jun 7 2016 1_2_91233774.dbf -rw-rw---- 1 oracle oinstall 1756731392 Jun 21 2016 1_3_91233774.dbf -rw-rw---- 1 oracle oinstall 1758001152 Jul 3 2016 1_4_91233774.dbf -rw-rw---- 1 oracle oinstall 1756729344 Jul 15 2016 1_5_91233774.dbf -rw-rw---- 1 oracle oinstall 1765750784 Jul 26 22:00 1_6_91233774.dbf -rw-rw---- 1 oracle oinstall 1760346112 Aug 6 14:04 1_7_91233774.dbf ......使用RMAN list archivelog all;查看日志也没有显示旧归档日志的记录RMAN> list archivelog all;
using target database control file instead of recovery catalog List of Archived Log Copies for database with db_unique_name DBS =====================================================================
Key Thrd Seq S Low Time ------- ---- ------- - --------- 1206 1 1206 A 14-JAN-17 Name: /opt/oracle/archive/db/1_1206_91233774.dbf
1207 1 1207 A 14-JAN-17 Name: /opt/oracle/archive/db/1_1207_91233774.dbf
using target database control file instead of recovery catalog allocated channel: ORA_DISK_1 channel ORA_DISK_1: SID=16 device type=DISK validation succeeded for archived log archived log file name=/opt/oracle/archive/db/1_1206_91233774.dbf RECID=1206 STAMP=933244655 validation succeeded for archived log archived log file name=/opt/oracle/archive/db/1_1207_91233774.dbf RECID=1207 STAMP=933249510 validation succeeded for archived log archived log file name=/opt/oracle/archive/db/1_1208_91233774.dbf RECID=1208 STAMP=933254500 validation succeeded for archived log archived log file name=/opt/oracle/archive/db/1_1209_91233774.dbf RECID=1209 STAMP=933259445 validation succeeded for archived log查看v$archived_log视图也没有旧归档日志记录 于是百度找到一篇文章http://3y.uu456.com/bp_3i90z4529l10ttd0odyk_1.html 大体意思是MAN删除归档日志的依据是controlfile中记录的归档日志，而不是你磁盘上实际存在的归档日志 ，如果你的归档日志已经不在controlfile中就无法被RMAN识别到，也就无法被删除。而致于归档信息何时在控制文件中被覆盖，这由一个参数control_file_record_keep_time来控制。 查看数据库中的参数是默认的7天 SYS@db> show parameter CONTROL_FILE_RECORD_KEEP_TIME
NAME TYPE VALUE ------------------------------------ -------------------------------- ------------------------------ control_file_record_keep_time integer 7难道是在控制文件中归档日志的记录条数只能保留7天的么？于是到MOS去找相关文档找到一篇Why Are Controlfile Entries For Archived Logs Not Overwritten After CONTROL_FILE_RECORD_KEEP_TIME？ （文档 ID 1056085.1），文档介绍CONTROL_FILE_RECORD_KEEP_TIME参数并不是强制在控制文件中保留多少天的归档日志条目，而是由V$CONTROLFILE_RECORD_SECTION视图中的ARCHIVED LOG条目去控制的，当RECORDS_TOTAL=RECORDS_USED时旧的归档日志就会被覆盖掉。 于是查数据库中的V$CONTROLFILE_RECORD_SECTION视图，看到ARCHIVED LOG行的records_total=224意味着控制文件中只能保留224条归档日志文件信息。 SYS@dbs> select * from v$controlfile_record_section where type="ARCHIVED LOG";
Do you really want to catalog the above files （enter YES or NO）？ yes cataloging files... cataloging done ...... RMAN> list archivelog all; ..... 1236 1 301 A 22-OCT-16 Name: /opt/oracle/archive/db/1_301_91233774.dbf
1237 1 302 A 22-OCT-16 Name: /opt/oracle/archive/db/1_302_91233774.dbf ......旧的归档日志文件已经注册到控制文件中了，再使用RMAN进行删除就可以了 delete archivelog until logseq 1007;再次查询v$controlfile_record_section视图，records_total也被“撑”大了 SYS@db> select * from v$controlfile_record_section where type="ARCHIVED LOG";
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