这种模式下主库出现坏块，当数据库被下一次被用到时自动利用备库来修复。 主库 SQL> select file_id, block_id, blocks from dba_extents where owner = 'SCOTT' and segment_name = 'T';    FILE_ID   BLOCK_ID     BLOCKS ---------- ---------- ----------      4     520          8 SQL> select min(rowid), max(rowid) from t; MIN(ROWID)     MAX(ROWID) ------------------ ------------------ AAASwmAAEAAAAILAAA AAASwmAAEAAAAIPAAj 自动段空间管理的数据是从第四个块开始。

可以通过dbms_rowid验证一下。 SQL> select DBMS_ROWID.ROWID_BLOCK_NUMBER('AAASwmAAEAAAAILAAA') min_block, DBMS_ROWID.ROWID_BLOCK_NUMBER('AAASwmAAEAAAAILAAj') max_block from dual; MIN_BLOCK  MAX_BLOCK ---------- ----------        523    523 构造坏块 RMAN> recover datafile 4 block 523 clear; Starting recover at 05-FEB-15 using target database control file instead of recovery catalog allocated channel: ORA_DISK_1 channel ORA_DISK_1: SID=37 device type=DISK Finished recover at 05-FEB-15 再次查询，数据直接就出来了。 SQL> select count(*) from t;   COUNT(*) ----------   72 alert日志 Thu Feb 05 14:30:48 2015 Hex dump of (file 4, block 523) in trace file /u01/app/oracle/diag/rdbms/orcl/orcl/trace/orcl_ora_6998.trc Corrupt block relative dba: 0x0100020b (file 4, block 523) Bad header found during multiblock buffer read Data in bad block: type: 6 format: 2 rdba: 0x3c24280b last change scn: 0x982f.a9d3a0d0 seq: 0xa2 flg: 0x5e spare1: 0x0 spare2: 0x0 spare3: 0x2f consistency value in tail: 0x38850602 check value in block header: 0xbbcf computed block checksum: 0x4e0 Reading datafile '/u01/oradata/orcl/users01.dbf' for corruption at rdba: 0x0100020b (file 4, block 523) Reread (file 4, block 523) found same corrupt data (no logical check) Starting background process ABMR Thu Feb 05 14:30:48 2015 ABMR started with pid=32, OS id=7016 Automatic block media recovery service is active.

Automatic block media recovery requested for (file# 4, block# 523)

Thu Feb 05 14:30:48 2015

Automatic block media recovery successful for (file# 4, block# 523)

Automatic block media recovery successful for (file# 4, block# 523)

WARNING: AutoBMR fixed mismatched on-disk block 3c24280b with in-mem rdba 100020b. 换成最大性能模式，重新制造坏块，查询时报错。 SQL> select count(*) from scott.t; select count(*) from scott.t                            * ERROR at line 1: ORA-01578: ORACLE data block corrupted (file # 4, block # 523) ORA-01110: data file 4: '/u01/oradata/orcl/users01.dbf' alert日志 Thu Feb 05 14:36:11 2015 Hex dump of (file 4, block 523) in trace file /u01/app/oracle/diag/rdbms/orcl/orcl/trace/orcl_ora_7120.trc Corrupt block relative dba: 0x0100020b (file 4, block 523) Bad check value found during multiblock buffer read Data in bad block: type: 6 format: 2 rdba: 0x0100020b last change scn: 0x0000.00103885 seq: 0x2 flg: 0x04 spare1: 0x0 spare2: 0x0 spare3: 0x0 consistency value in tail: 0x38850602 check value in block header: 0x5b3d computed block checksum: 0x8201 Reading datafile '/u01/oradata/orcl/users01.dbf' for corruption at rdba: 0x0100020b (file 4, block 523) Reread (file 4, block 523) found same corrupt data (no logical check) Thu Feb 05 14:36:11 2015 Corrupt Block Found          TSN = 4, TSNAME = USERS          RFN = 4, BLK = 523, RDBA = 16777739          OBJN = 76838, OBJD = 76838, OBJECT = T, SUBOBJECT =          SEGMENT OWNER = SCOTT, SEGMENT TYPE = Table Segment Errors in file /u01/app/oracle/diag/rdbms/orcl/orcl/trace/orcl_ora_7120.trc  (incident=18160): ORA-01578: ORACLE data block corrupted (file # 4, block # 523) ORA-01110: data file 4: '/u01/oradata/orcl/users01.dbf' Incident details in: /u01/app/oracle/diag/rdbms/orcl/orcl/incident/incdir_18160/orcl_ora_7120_i18160.trc Thu Feb 05 14:36:13 2015 Sweep [inc][18160]: completed Hex dump of (file 4, block 523) in trace file /u01/app/oracle/diag/rdbms/orcl/orcl/incident/incdir_18160/orcl_m000_7173_i18160_a.trc Corrupt block relative dba: 0x0100020b (file 4, block 523) Bad check value found during validation Data in bad block: type: 6 format: 2 rdba: 0x0100020b last change scn: 0x0000.00103885 seq: 0x2 flg: 0x04 spare1: 0x0 spare2: 0x0 spare3: 0x0 consistency value in tail: 0x38850602 check value in block header: 0x5b3d computed block checksum: 0x8201 Reread of blocknum=523, file=/u01/oradata/orcl/users01.dbf. found same corrupt data Reread of blocknum=523, file=/u01/oradata/orcl/users01.dbf. found same corrupt data Reread of blocknum=523, file=/u01/oradata/orcl/users01.dbf. found same corrupt data Reread of blocknum=523, file=/u01/oradata/orcl/users01.dbf. found same corrupt data Reread of blocknum=523, file=/u01/oradata/orcl/users01.dbf. found same corrupt data Thu Feb 05 14:36:13 2015 Dumping diagnostic data in directory=[cdmp_20150205143613], requested by (instance=1, osid=7120), summary=[incident=18160]. 此时oracle无法自动修复坏块。但是可以通过rman修复

接下来分两种情况

1 如果有备份，就从备份恢复。分别读数据文件备份和归档备份。 RMAN> recover datafile 4 block 523; Starting recover at 05-FEB-15 using target database control file instead of recovery catalog allocated channel: ORA_DISK_1 channel ORA_DISK_1: SID=20 device type=DISK channel ORA_DISK_1:  restoring block(s) channel ORA_DISK_1:  specifying block(s) to restore from backup set restoring blocks of datafile 00004 channel ORA_DISK_1: reading from backup piece /u01/app/oracle/fast_recovery_area/ORCL/backupset/2015_02_05/o1_mf_nnndf_TAG20150205T135105_bf6169pq_.bkp channel ORA_DISK_1: piece handle=/u01/app/oracle/fast_recovery_area/ORCL/backupset/2015_02_05/o1_mf_nnndf_TAG20150205T135105_bf6169pq_.bkp tag=TAG20150205T135105 channel ORA_DISK_1: restored block(s) from backup piece 1 channel ORA_DISK_1: block restore complete, elapsed time: 00:00:01 starting media recovery archived log for thread 1 with sequence 37 is already on disk as file /u01/oradata/orcl/arch/log_1_37_853863284.arc archived log for thread 1 with sequence 38 is already on disk as file /u01/oradata/orcl/arch/log_1_38_853863284.arc channel ORA_DISK_1: starting archived log restore to default destination channel ORA_DISK_1: restoring archived log archived log thread=1 sequence=36 channel ORA_DISK_1: reading from backup piece /u01/app/oracle/fast_recovery_area/ORCL/backupset/2015_02_05/o1_mf_annnn_TAG20150205T135243_bf619cvv_.bkp channel ORA_DISK_1: piece handle=/u01/app/oracle/fast_recovery_area/ORCL/backupset/2015_02_05/o1_mf_annnn_TAG20150205T135243_bf619cvv_.bkp tag=TAG20150205T135243 channel ORA_DISK_1: restored backup piece 1 channel ORA_DISK_1: restore complete, elapsed time: 00:00:01 media recovery complete, elapsed time: 00:00:01 Finished recover at 05-FEB-15 2 如果没有备份，就自动从备库修复 RMAN> recover datafile 4 block 523; Starting recover at 05-FEB-15 using channel ORA_DISK_1 finished standby search, restored 1 blocks starting media recovery media recovery complete, elapsed time: 00:00:01 Finished recover at 05-FEB-15 alert日志 Thu Feb 05 14:48:17 2015 alter database recover datafile list clear Completed: alter database recover datafile list clear Started Block Media Recovery Recovery of Online Redo Log: Thread 1 Group 2 Seq 50 Reading mem 0   Mem# 0: /u01/oradata/orcl/redo02.log Completed Block Media Recovery