节前帮网友打开了一套断电后无法正常启动的10.2.0.1数据库，该库使用非归档模式且没有任何备份。 主机断电后，该网友尝试重启数据库实例，但是遇到了ORA-00600:[kccpb_sanity_check_2]内部错误:
SQL> select status from v$instance; STATUS ------------ STARTED SQL> SQL> shutdown immediate; ORA-01507: database not mounted ORACLE instance shut down. SQL> startup mount; ORACLE instance started. Total System Global Area 2147483648 bytes Fixed Size 1220432 bytes Variable Size 486539440 bytes Database Buffers 1644167168 bytes Redo Buffers 15556608 bytes ORA-00600: internal error code, arguments: [kccpb_sanity_check_2], [8198], [8175], [0x0], [], [], [], []该kccpb_sanity_check_2内部错误常由不正确的control file中seq#记录引起，MOS note <ORA-00600: [kccpb_sanity_check_2] During Instance Startup>简单描述了该问题:
ORA-00600: [kccpb_sanity_check_2] During Instance Startup Applies to: Oracle Server - Enterprise Edition - Version: 10.2.0.1 and later [Release: 10.2 and later ] Information in this document applies to any platform. Symptoms The database is getting the following errors on Startup: ORA-00600: internal error code, arguments: [kccpb_sanity_check_2], [3621501], [3621462], [0x000000000] Changes In this case, the customer moved the box from one data center to another. Cause ORA-600 [kccpb_sanity_check_2] indicates that the seq# of the last read block is higher than the seq# of the control file header block. This is indication of the lost write of the header block during commit of the previous cf transaction. Solution 1) restore a backup of a controlfile and recover OR 2) recreate the controlfile OR 3) restore the database from last good backup and recover NOTE: If you do not have any special backup of control file to restore and you are using Multiple Control File copies in your pfile/init.ora/spfile you can attempt to mount the database using each control file one by one. If you are able to mount the database with any of these control file copies you can then issue 'alter database backup controlfile to trace' to recreate controlfile.针对该由control file corruption引起的ORA-00600: [kccpb_sanity_check_2] ，可以尝试一下三种解决方法:
- restore controlfile from backup
- 若有多路复用controlfile，则尝试使用每个单独的control file来mount实例，若能成功则使用该可用controlfile复制到其余位置
- 使用controlfile backup trace来重建控制文件，若没有trace那么也可以手动写create controlfile语句来重建
Create controlfile reuse set database "kmcdb"
MAXINSTANCES 8
MAXLOGHISTORY 1
MAXLOGFILES 16
MAXLOGMEMBERS 3
MAXDATAFILES 100
Datafile
'/u01/oracle/oradata/kmcdb/system01.dbf',
'/u01/oracle/oradata/kmcdb/undotbs01.dbf',
'/u01/oracle/oradata/kmcdb/sysaux01.dbf',
'/u01/oracle/oradata/kmcdb/users01.dbf',
'/u01/oracle/oradata/kmcdb/example01.dbf'
LOGFILE GROUP 1 ('/u01/oracle/oradata/kmcdb/redo01.log') SIZE 51200K,
GROUP 2 ('/u01/oracle/oradata/kmcdb/redo02.log') SIZE 51200K,
GROUP 3 ('/u01/oracle/oradata/kmcdb/redo03.log') SIZE 51200K RESETLOGS
Wed Sep 28 16:57:47 2011
WARNING: Default Temporary Tablespace not specified in CREATE DATABASE command
Default Temporary Tablespace will be necessary for a locally managed database in future release
Setting recovery target incarnation to 1
Wed Sep 28 16:57:48 2011
Successful mount of redo thread 1, with mount id 523482251
Wed Sep 28 16:57:48 2011
Completed: Create controlfile reuse set database "kmcdb"
MAXINSTANCES 8
MAXLOGHISTORY 1
MAXLOGFILES 16
MAXLOGMEMBERS 3
MAXDATAFILES 100
Datafile
'/u01/oracle/oradata/kmcdb/system01.dbf',
'/u01/oracle/oradata/kmcdb/undotbs01.dbf',
'/u01/oracle/oradata/kmcdb/sysaux01.dbf',
'/u01/oracle/oradata/kmcdb/users01.dbf',
'/u01/oracle/oradata/kmcdb/example01.dbf'
LOGFILE GROUP 1 ('/u01/oracle/oradata/kmcdb/redo01.log') SIZE 51200K,
GROUP 2 ('/u01/oracle/oradata/kmcdb/redo02.log') SIZE 51200K,
GROUP 3 ('/u01/oracle/oradata/kmcdb/redo03.log') SIZE 51200K RESETLOGS
Wed Sep 28 16:57:57 2011
alter database mount
成功mount实例后，尝试recover database 并 open 数据库 :
recover database using backup controlfile until cancel; 因为controlfile是重建出来的，所以当前的controlfile并不知道那个在线日志是current的，需要手动指定 ALTER DATABASE RECOVER database using backup controlfile until cancel Wed Sep 28 17:27:09 2011 Media Recovery Start WARNING! Recovering data file 1 from a fuzzy file. If not the current file it might be an online backup taken without entering the begin backup command. WARNING! Recovering data file 2 from a fuzzy file. If not the current file it might be an online backup taken without entering the begin backup command. WARNING! Recovering data file 3 from a fuzzy file. If not the current file it might be an online backup taken without entering the begin backup command. WARNING! Recovering data file 4 from a fuzzy file. If not the current file it might be an online backup taken without entering the begin backup command. WARNING! Recovering data file 5 from a fuzzy file. If not the current file it might be an online backup taken without entering the begin backup command. parallel recovery started with 7 processes ORA-279 signalled during: ALTER DATABASE RECOVER database using backup controlfile until cancel ... Wed Sep 28 17:27:20 2011 ALTER DATABASE RECOVER LOGFILE '/u01/oracle/oradata/kmcdb/redo02.log' Wed Sep 28 17:27:20 2011 Media Recovery Log /u01/oracle/oradata/kmcdb/redo02.log Errors with log /u01/oracle/oradata/kmcdb/redo02.log ORA-339 signalled during: ALTER DATABASE RECOVER LOGFILE '/u01/oracle/oradata/kmcdb/redo02.log' ... Wed Sep 28 17:27:20 2011 ALTER DATABASE RECOVER CANCEL ORA-1547 signalled during: ALTER DATABASE RECOVER CANCEL ... Wed Sep 28 17:27:37 2011 ALTER DATABASE RECOVER database using backup controlfile until cancel Wed Sep 28 17:27:37 2011 Media Recovery Start WARNING! Recovering data file 1 from a fuzzy file. If not the current file it might be an online backup taken without entering the begin backup command. WARNING! Recovering data file 2 from a fuzzy file. If not the current file it might be an online backup taken without entering the begin backup command. WARNING! Recovering data file 3 from a fuzzy file. If not the current file it might be an online backup taken without entering the begin backup command. WARNING! Recovering data file 4 from a fuzzy file. If not the current file it might be an online backup taken without entering the begin backup command. WARNING! Recovering data file 5 from a fuzzy file. If not the current file it might be an online backup taken without entering the begin backup command. parallel recovery started with 7 processes ORA-279 signalled during: ALTER DATABASE RECOVER database using backup controlfile until cancel ... Wed Sep 28 17:27:52 2011 ALTER DATABASE RECOVER LOGFILE '/u01/oracle/oradata/kmcdb/redo03.log' Wed Sep 28 17:27:52 2011 Media Recovery Log /u01/oracle/oradata/kmcdb/redo03.log Wed Sep 28 17:27:52 2011 Incomplete recovery applied all redo ever generated. Recovery completed through change 16228646 Wed Sep 28 17:27:52 2011 Media Recovery Complete (kmcdb) Completed: ALTER DATABASE RECOVER LOGFILE '/u01/oracle/oradata/kmcdb/redo03.log' Wed Sep 28 17:28:12 2011多次尝试后发现redo03.log是所需要的current group member，尝试alter database open resetlogs，但是出现ORA-00600: internal error code, arguments: [4000], [7], [], [], [], [], [], []错误:
alter database open resetlogs Wed Sep 28 17:28:12 2011 RESETLOGS is being done without consistancy checks. This may result in a corrupted database. The database should be recreated. RESETLOGS after incomplete recovery UNTIL CHANGE 16228646 Resetting resetlogs activation ID 523468297 (0x1f337e09) Online log /u01/oracle/oradata/kmcdb/redo01.log: Thread 1 Group 1 was previously cleared Online log /u01/oracle/oradata/kmcdb/redo02.log: Thread 1 Group 2 was previously cleared Wed Sep 28 17:28:12 2011 Setting recovery target incarnation to 5 Wed Sep 28 17:28:12 2011 Assigning activation ID 523485789 (0x1f33c25d) Thread 1 opened at log sequence 1 Current log# 3 seq# 1 mem# 0: /u01/oracle/oradata/kmcdb/redo03.log Successful open of redo thread 1 Wed Sep 28 17:28:12 2011 MTTR advisory is disabled because FAST_START_MTTR_TARGET is not set Wed Sep 28 17:28:12 2011 SMON: enabling cache recovery Wed Sep 28 17:28:12 2011 Errors in file /u01/oracle/admin/kmcdb/udump/kmcdb_ora_31798.trc: ORA-00600: internal error code, arguments: [4000], [7], [], [], [], [], [], [] Wed Sep 28 17:28:14 2011 Errors in file /u01/oracle/admin/kmcdb/udump/kmcdb_ora_31798.trc: ORA-00704: bootstrap process failure ORA-00704: bootstrap process failure ORA-00600: internal error code, arguments: [4000], [7], [], [], [], [], [], []以上ORA-00600: [4000], [7],说明在使用usn=7的回滚段rollback数据块时发现rollback segment存在讹误(注意不要和ora600 [2662]错误混淆]，且该ORA-00600: [4000]伴随有ORA-00704: bootstrap process failure错误，说明需要回滚的数据块是bootstrap重要的自举对象。 一般来说bootstrap object需要做rollback或cleanup而apply undo数据时，我们是无法使用_corrupted_rollback_segments,_offline_rollback_segments或10513事件来阻止ORA-00600: [4000]的发生。 但还是仍心存侥幸，修改_corrupted_rollback_segments,_offline_rollback_segments和event参数再次尝试:
alter system set event='10513 trace name context forever,level 2 : 10512 trace name context forever,level 1: 10511 trace name context forever,level 2: 10510 trace name context forever,level 1' scope=spfile; ALTER SYSTEM SET _offline_rollback_segments='(_SYSSMU7$)' SCOPE=SPFILE; ALTER SYSTEM SET _corrupted_rollback_segments='(_SYSSMU7$)' SCOPE=SPFILE; 再次open database alter database open resetlogs Wed Sep 28 17:47:05 2011 RESETLOGS after complete recovery through change 16228668 Resetting resetlogs activation ID 523471415 (0x1f338a37) Online log /u01/oracle/oradata/kmcdb/redo01.log: Thread 1 Group 1 was previously cleared Online log /u01/oracle/oradata/kmcdb/redo02.log: Thread 1 Group 2 was previously cleared Wed Sep 28 17:47:05 2011 Setting recovery target incarnation to 11 Wed Sep 28 17:47:05 2011 Assigning activation ID 523466708 (0x1f3377d4) Thread 1 opened at log sequence 1 Current log# 3 seq# 1 mem# 0: /u01/oracle/oradata/kmcdb/redo03.log Successful open of redo thread 1 Wed Sep 28 17:47:05 2011 MTTR advisory is disabled because FAST_START_MTTR_TARGET is not set Wed Sep 28 17:47:05 2011 SMON: enabling cache recovery Wed Sep 28 17:47:05 2011 Errors in file /u01/oracle/admin/kmcdb/udump/kmcdb_ora_32261.trc: ORA-00600: internal error code, arguments: [4000], [7], [], [], [], [], [], [] Wed Sep 28 17:47:06 2011 Errors in file /u01/oracle/admin/kmcdb/udump/kmcdb_ora_32261.trc: ORA-00704: bootstrap process failure ORA-00704: bootstrap process failure ORA-00600: internal error code, arguments: [4000], [7], [], [], [], [], [], [] Wed Sep 28 17:47:06 2011 Error 704 happened during db open, shutting down database USER: terminating instance due to error 704 Instance terminated by USER, pid = 32261 ORA-1092 signalled during: alter database open resetlogs...无法避免bootstrap对象发生ORA-00600:[4000]，而这对打开数据库来说是致命的，要想恢复这个数据库就必须要解决该bootstrap对象。 怎么办呢？ 我们先来读一读ORA-00600:[4000]内部错误的trace日志:
*** SERVICE NAME:() 2011-09-28 17:46:09.022
*** SESSION ID:(160.3) 2011-09-28 17:46:09.022
Recovery target incarnation = 10, activation ID = 0
Influx buffer limit = 98098 (50% x 196196)
Successfully allocated 7 recovery slaves
Using 156 overflow buffers per recovery slave
Start recovery at thread 1 ckpt scn 16228666 logseq 1 block 2
*** 2011-09-28 17:46:09.236
Media Recovery add redo thread 1
*** 2011-09-28 17:46:14.752
Media Recovery drop redo thread 1
*** 2011-09-28 17:46:41.788
Recovery target incarnation = 10, activation ID = 0
Influx buffer limit = 98098 (50% x 196196)
Successfully allocated 7 recovery slaves
Using 156 overflow buffers per recovery slave
Start recovery at thread 1 ckpt scn 16228666 logseq 1 block 2
*** 2011-09-28 17:46:41.842
Media Recovery add redo thread 1
*** 2011-09-28 17:46:52.799
Media Recovery Log /u01/oracle/oradata/kmcdb/redo03.log
----- Redo read statistics for thread 1 -----
Read rate (ASYNC): 0Kb in 10.99s => 0.00 Mb/sec
Total physical reads: 4096Kb
Longest record: 0Kb, moves: 0/1 (0%)
Change moves: 0/1 (0%), moved: 0Mb
Longest LWN: 0Kb, moves: 0/1 (0%), moved: 0Mb
Last redo scn: 0x0000.00f7a13b (16228667)
----------------------------------------------
*** 2011-09-28 17:46:52.835
Media Recovery drop redo thread 1
File 1 (stop scn 16228668) completed recovery at checkpoint scn 16228668
File 2 (stop scn 16228668) completed recovery at checkpoint scn 16228668
File 3 (stop scn 16228668) completed recovery at checkpoint scn 16228668
File 4 (stop scn 16228668) completed recovery at checkpoint scn 16228668
File 5 (stop scn 16228668) completed recovery at checkpoint scn 16228668
ARCH: Connecting to console port...
*** 2011-09-28 17:47:05.351
Prior to RESETLOGS processing...
ALTER SYSTEM ARCHIVE LOG ALL USING BACKUP CONTROLFILE start
Database is not in archivelog mode
ALTER SYSTEM ARCHIVE LOG ALL USING BACKUP CONTROLFILE complete
*** 2011-09-28 17:47:05.353
*** 2011-09-28 17:47:05.707
ksedmp: internal or fatal error
ORA-00600: internal error code, arguments: [4000], [7], [], [], [], [], [], []
Current SQL statement for this session:
select ctime, mtime, stime from obj$ where obj# = :1
----- Call Stack Trace -----
calling call entry argument values in hex
location type point (? means dubious value)
-------------------- -------- -------------------- ----------------------------
ksedst()+27 call ksedst1() 0 ? 1 ?
ksedmp()+557 call ksedst() 0 ? 9EF2E6D0 ? 0 ? 2A ?
9CCB06F4 ? 70000 ?
ksfdmp()+19 call ksedmp() 3 ? BFAA18D0 ? AC152A0 ?
CBD2D40 ? 3 ? CB843B8 ?
kgeriv()+188 call 00000000 CBD2D40 ? 3 ?
kgeasi()+113 call kgeriv() CBD2D40 ? B7EB0020 ? FA0 ?
1 ? BFAA190C ?
ktudba()+264 call kgeasi() CBD2D40 ? B7EB0020 ? FA0 ?
2 ? 1 ? 0 ? 7 ? 0 ?
ktrgcm()+6207 call ktudba() 7 ? BFAA1DEC ? 0 ? 0 ?
ktrgtc()+941 call ktrgcm() B7EFF4F4 ? 0 ? B7EFE054 ?
96F1A0B4 ? 96F10CE8 ? 198 ?
kdsgrp()+107 call ktrgtc() B7EFF4F4 ? B7EFF49C ?
9C22142 ? BFAA1F08 ? 240 ?
9C24DC4 ? 9C21D7C ?
kdsfbrcb()+513 call kdsgrp() B7EFF4F0 ? 0 ? B7EFF4F0 ?
qertbFetchByRowID() call kdsfbrcb() B7EFF4F0 ? B7EFDFEC ? 0 ? 1 ?
+2052 0 ? 0 ?
opifch2()+5157 call 00000000 96F10A8C ? A11CDE4 ?
BFAA2534 ? 1 ?
引发ORA-00600:[4000]错误的数据块头信息:
Block header dump: 0x0040007a
Object id on Block? Y
seg/obj: 0x12 csc: 0x00.f84ef0 itc: 1 flg: - typ: 1 - DATA
fsl: 0 fnx: 0x0 ver: 0x01
Itl Xid Uba Flag Lck Scn/Fsc
0x01 0x0007.01f.000011cf 0x00800057.0faf.07 --U- 1 fsc 0x0000.00f84ef1
data_block_dump,data header at 0x82bba044
以上的trace文件信息量极大，我们来抽丝剥茧的罗列这些信息量: 1. File 1 (stop scn 16228668) completed recovery at checkpoint scn 16228668， 这条日志指出了1号数据文件最后恢复到的checkpoint scn，当尝试open database时数据库当前的scn将从16228668开始 2. ORA-00600: internal error code, arguments: [4000], [7], [], [], [], [], [], [] Current SQL statement for this session: select ctime, mtime, stime from obj$ where obj# = :1 引发ORA-00600:[4000], [7]错误的语句是"select ctime, mtime, stime from obj$ where obj# = :1"，这是一条常用的递归SQL语句，查询的对象是非常critical的bootstrap自举对象OBJ$基表，这说明需要cleanup的块时OBJ$表上的 3. 引发ORA-00600:[4000] raised是ktudba函数，由它触发了oracle 错误机制，其stack call为kdsgrp-> ktrgtc -> ktrgcm -> ktudba -> kgeasi(错误处理函数) 4. 引发ORA-00600:[4000], [7]错误的数据块是1号数据文件的122块，seg/obj为0x12，块类型为Data，且存在有一条ITL entry: Itl Xid Uba Flag Lck Scn/Fsc 0x01 0x0007.01f.000011cf 0x00800057.0faf.07 --U- 1 fsc 0x0000.00f84ef1 该ITL 的Scn为00f84ef1= 16273137 > current_scn=16228668 且lck=1 这里存在一个问题: 为什么这个"select ctime, mtime, stime from obj$ where obj# = :1"查询语句要针对该OBJ$的数据块访问该块上ITL相关的rollback segment呢？ 这里要牵扯到Oracle中查询语句构建CR一致性读块和块延迟清除的一些概念： 1. 当现有的buffer block无法满足查询的SCN要求时，查询进程会通过现有buffer和undo信息构造出一个CR块来。譬如说cache中现有的一个block的SCN是10，而我的查询语句其实是从Scn=1时就开始的，那么这个查询语句的Snap_scn就是1，为了满足其SCN的需求，就需要访问相关的rollback segment 并对 buffer block做"rollback"。 2. 另一方面当查询语句访问块时，可能需要对块做cleanup，也就是我们说的延迟块清除(deferred block cleanout),当这种Block Cleanout发生时查询进程也需要去访问块上ITL相关的 rollback segment ，那么具体当访问到哪些块时需要做cleanout呢？这个将会在今后的文章中详述。 回归到上面的ORA-00600:[4000]中来，因为该致命内部错误涉及到的对象是重要的Bootstrap表OBJ$，所以无法使用传统的例如_corrupted_rollback_segments,_offline_rollback_segments或10513事件来阻止ORA-00600: [4000]的发生，必须使用块修改工具BBED来修改存在问题的数据块将ITL事务槽的FLAG从U修改为C(Commit)。 TRANSACTION_COMMITED = 0x08; TRANSACTION_UPBOUND = 0x02; TRANSACTION_ACTIVE = 0x01; Flag= --U- 即TRANSACTION_UPBOUND时flag所占字节为0x02，需要将该字节修改为TRANSACTION_COMMITED = 0x08; 十分不巧的是，通过QQ远程协助帮助这位网友使用BBED打开了数据块，但因为这位网友的Terminal工具存在问题导致日志没有记全，特别是BBED这部分的：
[oracle@DBserver1 lib]$ cd /u01/oracle/oradata/kmcdb/
[oracle@DBserver1 kmcdb]$ ls
control01.ctl control02.ctl.bak ctl_backup redo02.log system01.dbf users01.dbf
control01.ctl.bak control03.ctl example01.dbf redo03.log temp01.dbf
control02.ctl control03.ctl.bak redo01.log sysaux01.dbf undotbs01.dbf
[oracle@DBserver1 kmcdb]$ cp system01.dbf ctl_backup/
[oracle@DBserver1 kmcdb]$ cp system01.dbf system01.dbf.bak
在正式BBED之前一定要备份所有的数据文件
oracle@DBserver1 kmcdb]$ bbed filename=system01.dbf password=blockedit mode=edit
BBED: Release 2.0.0.0.0 - Limited Production on Wed Sep 28 21:22:41 2011
Copyright (c) 1982, 2005, Oracle. All rights reserved.
BBED> set blocksize 8192
BLOCKSIZE 8192
BBED> set block 123
BLOCK# 123
BBED> map /v
File: system01.dbf (0)
Block: 123 Dba:0x00000000
------------------------------------------------------------
KTB Data Block (Table/Cluster)
struct kcbh, 20 bytes @0
ub1 type_kcbh @0
ub1 frmt_kcbh @1
ub1 spare1_kcbh @2
ub1 spare2_kcbh @3
ub4 rdba_kcbh @4
ub4 bas_kcbh @8
ub2 wrp_kcbh @12
ub1 seq_kcbh @14
ub1 flg_kcbh @15
ub2 chkval_kcbh @16
ub2 spare3_kcbh @18
struct ktbbh, 48 bytes @20
ub1 ktbbhtyp @20
union ktbbhsid, 4 bytes @24
struct ktbbhcsc, 8 bytes @28
b2 ktbbhict @36
ub1 ktbbhflg @38
ub1 ktbbhfsl @39
ub4 ktbbhfnx @40
struct ktbbhitl[1], 24 bytes @44
struct kdbh, 14 bytes @68
ub1 kdbhflag @68
b1 kdbhntab @69
b2 kdbhnrow @70
sb2 kdbhfrre @72
sb2 kdbhfsbo @74
sb2 kdbhfseo @76
b2 kdbhavsp @78
b2 kdbhtosp @80
struct kdbt[1], 4 bytes @82
b2 kdbtoffs @82
b2 kdbtnrow @84
sb2 kdbr[108] @86
ub1 freespace[873] @302
ub1 rowdata[7013] @1175
ub4 tailchk @8188
ITL记录从 struct ktbbhitl[1], 24 bytes @44 开始
BBED> set offset 61
OFFSET 61
BBED> d
File: system01.dbf (0)
Block: 123 Offsets: 61 to 572 Dba:0x00000000
------------------------------------------------------------------------
200000f1 4ef80000 016c00ff ffea0053 04690369 0300006c 007b1f3a 1ffe1ec1
1e801e40 1ef81db8 1d771d29 1dec1cb0 1c681c27 1ce71ba7 1b681b27 1beb1aaf
1a701a2f 1af319b4 19731937 19f118ae 18671827 18e717a7 1766172b 17e316a2
1661161f 16e315a3 15661529 15e914a8 146c142c 14ec13b0 13731332 13f112b0
126f122f 12ee11a0 11601121 11de109b 105f1023 10e60fa3 0f620f1d 0fd80e9c
0e5a0e14 0ed30d94 0d540d13 0dd30c93 0c570c17 0cd90b98 0b580b15 0bd00a8b
0a460a01 0ac10981 09410901 09c0087d 083e0801 08bc077e 074207fc 06bb0674
063206f0 05aa0564 051e05d8 04950453 04000000 00000000 00000000 00000000
00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
BBED> modify /x 0x80
#modify /x 20 filename 'system01.dbf' block 123. offset 61.
sum apply
verify
因为该ITL事务槽的lck=1，因此还需要将lb: 0x1的row piece记录修改为lb: 0x0
在trace中，该记录为
tab 0, row 26, @0x18f1
tl: 70 fb: --H-FL-- lb: 0x1 cc: 17
col 0: [ 2] c1 02
col 1: [ 4] c3 08 61 2c
col 2: [ 1] 80
col 3: [12] 5f 4e 45 58 54 5f 4f 42 4a 45 43 54
col 4: [ 2] c1 02
col 5: *NULL*
set offset 6454
modify /x 0x00
#modify /x 01 filename 'system01.dbf' block 123. offset 6454.
sum apply
verify
以上完成了对OBJ$上数据块的修改
完成以上BBED手动修改操作后，再次打开数据库成功，但是发现有很多坏块:
alter database open resetlogs
Wed Sep 28 21:42:53 2011
RESETLOGS after complete recovery through change 16228672
Resetting resetlogs activation ID 523466708 (0x1f3377d4)
Online log /u01/oracle/oradata/kmcdb/redo01.log: Thread 1 Group 1 was previously cleared
Online log /u01/oracle/oradata/kmcdb/redo02.log: Thread 1 Group 2 was previously cleared
Wed Sep 28 21:42:54 2011
Setting recovery target incarnation to 12
Wed Sep 28 21:42:54 2011
Assigning activation ID 523426694 (0x1f32db86)
Thread 1 opened at log sequence 1
Current log# 3 seq# 1 mem# 0: /u01/oracle/oradata/kmcdb/redo03.log
Successful open of redo thread 1
Wed Sep 28 21:42:54 2011
MTTR advisory is disabled because FAST_START_MTTR_TARGET is not set
Wed Sep 28 21:42:54 2011
SMON: enabling cache recovery
Wed Sep 28 21:42:54 2011
Dictionary check beginning
Tablespace 'TEMP' #3 found in data dictionary,
but not in the controlfile. Adding to controlfile.
Corrected file 5 plugged in read-only status in control file
Dictionary check complete
Wed Sep 28 21:42:54 2011
SMON: enabling tx recovery
Wed Sep 28 21:42:54 2011
*********************************************************************
WARNING: The following temporary tablespaces contain no files.
This condition can occur when a backup controlfile has
been restored. It may be necessary to add files to these
tablespaces. That can be done using the SQL statement:
ALTER TABLESPACE ADD TEMPFILE
Alternatively, if these temporary tablespaces are no longer
needed, then they can be dropped.
Empty temporary tablespace: TEMP
*********************************************************************
Updating character set in controlfile to ZHS16GBK
Wed Sep 28 21:42:54 2011
Errors in file /u01/oracle/admin/kmcdb/bdump/kmcdb_smon_32531.trc:
ORA-00600: internal error code, arguments: [2662], [0], [16273152], [0], [16273158], [4220957], [], []
**********************************************************
WARNING: Files may exists in db_recovery_file_dest
that are not known to the database. Use the RMAN command
CATALOG RECOVERY AREA to re-catalog any such files.
One of the following events caused this:
1. A backup controlfile was restored.
2. A standby controlfile was restored.
3. The controlfile was re-created.
4. db_recovery_file_dest had previously been enabled and
then disabled.
**********************************************************
replication_dependency_tracking turned off (no async multimaster replication found)
WARNING: AQ_TM_PROCESSES is set to 0. System operation might be adversely affected.
Wed Sep 28 21:42:55 2011
LOGSTDBY: Validating controlfile with logical metadata
Wed Sep 28 21:42:55 2011
LOGSTDBY: Validation complete
ORA-01555 caused by SQL statement below (SQL ID: 96g93hntrzjtr, SCN: 0x0000.00f84f0a):
Wed Sep 28 21:42:55 2011
select /*+ rule */ bucket_cnt, row_cnt, cache_cnt, null_cnt, timestamp#, sample_size, minimum,
maximum, distcnt, lowval, hival, density, col#, spare1, spare2, avgcln from hist_head$ where obj#=:1 and intcol#=:2
Global Name changed to KMCDB
Wed Sep 28 21:42:55 2011
Non-fatal internal error happenned while SMON was doing non-existent object cleanup.
SMON encountered 1 out of maximum 100 non-fatal internal errors.
Wed Sep 28 21:42:56 2011
Completed: alter database open resetlogs
Wed Sep 28 21:42:57 2011
Hex dump of (file 1, block 61479) in trace file /u01/oracle/admin/kmcdb/bdump/kmcdb_smon_32531.trc
Corrupt block relative dba: 0x0040f027 (file 1, block 61479)
Fractured block found during buffer read
Data in bad block:
type: 6 format: 2 rdba: 0x0040f027
last change scn: 0x0000.00f80906 seq: 0x1 flg: 0x06
spare1: 0x0 spare2: 0x0 spare3: 0x0
consistency value in tail: 0x36a70601
check value in block header: 0xe5d2
computed block checksum: 0x3fa1
Reread of rdba: 0x0040f027 (file 1, block 61479) found same corrupted data
Wed Sep 28 21:42:57 2011
Errors in file /u01/oracle/admin/kmcdb/bdump/kmcdb_smon_32531.trc:
ORA-00604: error occurred at recursive SQL level 1
ORA-01578: ORACLE data block corrupted (file # 1, block # 61479)
ORA-01110: data file 1: '/u01/oracle/oradata/kmcdb/system01.dbf'
Wed Sep 28 21:42:58 2011
Starting background process CJQ0
CJQ0 started with pid=24, OS id=724
Wed Sep 28 21:43:01 2011
Errors in file /u01/oracle/admin/kmcdb/bdump/kmcdb_m000_720.trc:
ORA-00600: internal error code, arguments: [2662], [0], [16273222], [0], [16273348], [12624044], [], []
Wed Sep 28 21:43:02 2011
Errors in file /u01/oracle/admin/kmcdb/bdump/kmcdb_m000_720.trc:
ORA-00600: internal error code, arguments: [2662], [0], [16273288], [0], [16273348], [12624044], [], []
ORA-00600: internal error code, arguments: [2662], [0], [16273222], [0], [16273348], [12624044], [], []
Wed Sep 28 21:44:35 2011
create temporary tablespace temp02 tempfile '/u01/oracle/oradata/temp02.dbf' size 400M
Wed Sep 28 21:44:35 2011
Completed: create temporary tablespace temp02 tempfile '/u01/oracle/oradata/temp02.dbf' size 400M
Wed Sep 28 21:45:52 2011
create undo tablespace undo03 datafile '/u01/oracle/oradata/undo03.dbf' size 500M
Hex dump of (file 3, block 3839) in trace file /u01/oracle/admin/kmcdb/udump/kmcdb_ora_749.trc
Corrupt block relative dba: 0x00c00eff (file 3, block 3839)
Fractured block found during buffer read
Data in bad block:
type: 6 format: 2 rdba: 0x00c00eff
last change scn: 0x0000.00f7be10 seq: 0x1 flg: 0x06
spare1: 0x0 spare2: 0x0 spare3: 0x0
consistency value in tail: 0x49b20601
check value in block header: 0xe0a3
computed block checksum: 0xf7a2
Reread of rdba: 0x00c00eff (file 3, block 3839) found same corrupted data
Completed: create undo tablespace undo03 datafile '/u01/oracle/oradata/undo03.dbf' size 500M
Wed Sep 28 21:45:58 2011
Errors in file /u01/oracle/admin/kmcdb/bdump/kmcdb_smon_32531.trc:
ORA-00600: internal error code, arguments: [4097], [], [], [], [], [], [], []
Wed Sep 28 21:45:58 2011
Non-fatal internal error happenned while SMON was doing Corrupt Block Seg Info.
SMON encountered 2 out of maximum 100 non-fatal internal errors.
Wed Sep 28 21:47:15 2011
ALTER SYSTEM SET undo_management='AUTO' SCOPE=SPFILE;
Wed Sep 28 21:47:19 2011
Starting background process EMN0
EMN0 started with pid=22, OS id=757
Wed Sep 28 21:47:19 2011
Shutting down instance: further logons disabled
Wed Sep 28 21:47:19 2011
Stopping background process CJQ0
Wed Sep 28 21:47:19 2011
尝试创建并切换到新的Undo表空间，可能可以避免一些后续出现的ORA-600问题。 以上alert.log中2662和4097内部错误暂时不导致数据库crash，但是因为是用非常手段打开的数据库所以这套数据库已不再稳定，所以要第一时间逻辑和物理备份重要数据， 并着手重建数据库:
run{
set maxcorrupt for datafile 1,2,3,4,5 to 100;
backup as compressed backupset incremental level 0 database;
}
exp system/oracle full=y file=full.dmp
虽然该网友和我一再强调他的数据库中的数据十分重要，但是他的行为是在无声的诉说这套数据库里的数据是无关紧要的。 如果你觉得数据是important的，那么请善待数据。 善待数据的第一条准则是 数据备份重于一切，如果没有备份 那么请不要奢望数据是持久的！
本文转自maclean_007 51CTO博客，原文链接:http://blog.51cto.com/maclean/1278106
