标签归档：bbed修复坏块

在rman中有隐藏的命令clear,可以标记数据块为corrupt,从而实现数据库坏块试验,本篇blog通过dbv,bbed,table select来验证坏块的出现和修复
创建测试表

SQL>  create table t_xifenfei as  
  2   select object_id,object_name from dba_objects where rownum<10;

Table created.

SQL>  select rowid,
  2   dbms_rowid.rowid_relative_fno(rowid) rel_fno,
  3   dbms_rowid.rowid_block_number(rowid) block
  4   from chf.t_xifenfei;

ROWID                 REL_FNO      BLOCK
------------------ ---------- ----------
AAAStAAAEAAAACrAAA          4        171
AAAStAAAEAAAACrAAB          4        171
AAAStAAAEAAAACrAAC          4        171
AAAStAAAEAAAACrAAD          4        171
AAAStAAAEAAAACrAAE          4        171
AAAStAAAEAAAACrAAF          4        171
AAAStAAAEAAAACrAAG          4        171
AAAStAAAEAAAACrAAH          4        171
AAAStAAAEAAAACrAAI          4        171

9 rows selected.

SQL> alter system checkpoint;

System altered.

dbv验证坏块

[oracle@xifenfei ~]$ dbv file=/u01/oracle/oradata/ora11g/users01.dbf

DBVERIFY: Release 11.2.0.3.0 - Production on Sun Jan 20 09:12:16 2013

Copyright (c) 1982, 2011, Oracle and/or its affiliates.  All rights reserved.

DBVERIFY - Verification starting : FILE = /u01/oracle/oradata/ora11g/users01.dbf


DBVERIFY - Verification complete

Total Pages Examined         : 7680
Total Pages Processed (Data) : 3776
Total Pages Failing   (Data) : 0
Total Pages Processed (Index): 167
Total Pages Failing   (Index): 0
Total Pages Processed (Other): 744
Total Pages Processed (Seg)  : 0
Total Pages Failing   (Seg)  : 0
Total Pages Empty            : 2993
Total Pages Marked Corrupt   : 0
Total Pages Influx           : 0
Total Pages Encrypted        : 0
Highest block SCN            : 1006717955 (2956.1006717955)

这里创建了t_xifenfei表,数据存储在file 4 block 171中,现在该block一切正常,本试验就是要通过rman来使得该block corrupt,然后通过bbed来修复

bbed查看kcbh

BBED> set block 171
        BLOCK#          171

BBED> p kcbh
struct kcbh, 20 bytes                       @0       
   ub1 type_kcbh                            @0        0x06
   ub1 frmt_kcbh                            @1        0xa2
   ub1 spare1_kcbh                          @2        0x00
   ub1 spare2_kcbh                          @3        0x00
   ub4 rdba_kcbh                            @4        0x010000ab
   ub4 bas_kcbh                             @8        0x3c014bfe
   ub2 wrp_kcbh                             @12       0x0b8c
   ub1 seq_kcbh                             @14       0x02
   ub1 flg_kcbh                             @15       0x04 (KCBHFCKV)
   ub2 chkval_kcbh                          @16       0x6e0c  <--重点关注
   ub2 spare3_kcbh                          @18       0x0000

rman标记坏块

RMAN> BLOCKRECOVER DATAFILE 4 block 171 clear;

Starting recover at 20-JAN-13
using target database control file instead of recovery catalog
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=18 device type=DISK
Finished recover at 20-JAN-13

dbv再次检查坏块

[oracle@xifenfei ~]$ dbv file=/u01/oracle/oradata/ora11g/users01.dbf

DBVERIFY: Release 11.2.0.3.0 - Production on Sun Jan 20 09:53:16 2013

Copyright (c) 1982, 2011, Oracle and/or its affiliates.  All rights reserved.

DBVERIFY - Verification starting : FILE = /u01/oracle/oradata/ora11g/users01.dbf
Page 171 is marked corrupt
Corrupt block relative dba: 0x010000ab (file 4, block 171)
Bad check value found during dbv: 
Data in bad block:
 type: 6 format: 2 rdba: 0x010000ab
 last change scn: 0x0b8c.3c014bfe seq: 0x2 flg: 0x04
 spare1: 0x0 spare2: 0x0 spare3: 0x0
 consistency value in tail: 0x4bfe0602
 check value in block header: 0x6e0c
 computed block checksum: 0xb5bc


DBVERIFY - Verification complete

Total Pages Examined         : 7680
Total Pages Processed (Data) : 3775
Total Pages Failing   (Data) : 0
Total Pages Processed (Index): 167
Total Pages Failing   (Index): 0
Total Pages Processed (Other): 744
Total Pages Processed (Seg)  : 0
Total Pages Failing   (Seg)  : 0
Total Pages Empty            : 2993
Total Pages Marked Corrupt   : 1
Total Pages Influx           : 1
Total Pages Encrypted        : 0
Highest block SCN            : 1006717955 (2956.1006717955)

尝试查询数据

SQL> select count(*) from t_xifenfei;
select count(*) from t_xifenfei
                     *
ERROR at line 1:
ORA-01578: ORACLE data block corrupted (file # 4, block # 171)
ORA-01110: data file 4: '/u01/oracle/oradata/ora11g/users01.dbf'

bbed验证坏块

BBED> set block 171
        BLOCK#          171

BBED> p kcbh
struct kcbh, 20 bytes                       @0       
   ub1 type_kcbh                            @0        0x06
   ub1 frmt_kcbh                            @1        0xa2
   ub1 spare1_kcbh                          @2        0x00
   ub1 spare2_kcbh                          @3        0x00
   ub4 rdba_kcbh                            @4        0x010000ab
   ub4 bas_kcbh                             @8        0x3c014bfe
   ub2 wrp_kcbh                             @12       0x0b8c
   ub1 seq_kcbh                             @14       0x02
   ub1 flg_kcbh                             @15       0x04 (KCBHFCKV)
   ub2 chkval_kcbh                          @16       0x6e0c  <--注意该值未变化
   ub2 spare3_kcbh                          @18       0x0000

BBED> verify
DBVERIFY - Verification starting
FILE = /u01/oracle/oradata/ora11g/users01.dbf
BLOCK = 171

Block 171 is corrupt
Corrupt block relative dba: 0x010000ab (file 0, block 171)
Bad check value found during verification
Data in bad block:
 type: 6 format: 2 rdba: 0x010000ab
 last change scn: 0x0b8c.3c014bfe seq: 0x2 flg: 0x04
 spare1: 0x0 spare2: 0x0 spare3: 0x0
 consistency value in tail: 0x4bfe0602
 check value in block header: 0x6e0c
 computed block checksum: 0xb5bc


DBVERIFY - Verification complete

Total Blocks Examined         : 1
Total Blocks Processed (Data) : 0
Total Blocks Failing   (Data) : 0
Total Blocks Processed (Index): 0
Total Blocks Failing   (Index): 0
Total Blocks Empty            : 0
Total Blocks Marked Corrupt   : 1
Total Blocks Influx           : 0
Message 531 not found;  product=RDBMS; facility=BBED

这里通过dbv,bbed,select table都证明rman能够标记block为Corrupt.
这里需要分析:block已经被标记,那证明该块肯定有修改,也就是说chkval_kcbh一定要变化,但是这里没有变化,证明该处异常

bbed修复rman生成坏块

BBED> sum apply
Warning: contents of previous BIFILE will be lost. Proceed? (Y/N) y
Check value for File 0, Block 171:
current = 0xdbb0, required = 0xdbb0

BBED> verify
DBVERIFY - Verification starting
FILE = /u01/oracle/oradata/ora11g/users01.dbf
BLOCK = 171


DBVERIFY - Verification complete

Total Blocks Examined         : 1
Total Blocks Processed (Data) : 1
Total Blocks Failing   (Data) : 0
Total Blocks Processed (Index): 0
Total Blocks Failing   (Index): 0
Total Blocks Empty            : 0
Total Blocks Marked Corrupt   : 0
Total Blocks Influx           : 0
Message 531 not found;  product=RDBMS; facility=BBED

bbed测试坏块已经修复

dbv验证坏块

[oracle@xifenfei ~]$ dbv file=/u01/oracle/oradata/ora11g/users01.dbf

DBVERIFY: Release 11.2.0.3.0 - Production on Sun Jan 20 10:01:46 2013

Copyright (c) 1982, 2011, Oracle and/or its affiliates.  All rights reserved.

DBVERIFY - Verification starting : FILE = /u01/oracle/oradata/ora11g/users01.dbf

DBVERIFY - Verification complete

Total Pages Examined         : 7680
Total Pages Processed (Data) : 3776
Total Pages Failing   (Data) : 0
Total Pages Processed (Index): 167
Total Pages Failing   (Index): 0
Total Pages Processed (Other): 744
Total Pages Processed (Seg)  : 0
Total Pages Failing   (Seg)  : 0
Total Pages Empty            : 2993
Total Pages Marked Corrupt   : 0
Total Pages Influx           : 0
Total Pages Encrypted        : 0
Highest block SCN            : 1006717955 (2956.1006717955)

dbv测试坏块也被修复

查询表验证

SQL> select count(*) from t_xifenfei;

  COUNT(*)
----------
         9

数据也可以正常查询,证明rman的坏块问题通过bbed解决

总结说明
1.我们可以通过rman的clear命令来标记坏块(BLOCKRECOVER DATAFILE file# BLOCK block1#, block2#, block3#… CLEAR ;)
2.我们可以通过bbed的sum apply命令来修复该类型坏块