标签归档:bbed

bbed处理ORA-01200故障

一个朋友的测试库出现ORA-01200错误,正好周末比较空闲,随手帮他使用bbed进行了恢复,给广大朋友提供一种解决该问题的方法
数据库启动报错

C:\Users\Administrator>sqlplus /nolog

SQL*Plus: Release 11.1.0.6.0 - Production on 星期日 5月 12 22:09:11 2013

Copyright (c) 1982, 2007, Oracle.  All rights reserved.

SQL> connect/as sysdba
已连接到空闲例程。
SQL> startup force
ORACLE 例程已经启动。

Total System Global Area 1071333376 bytes
Fixed Size                  1334380 bytes
Variable Size             318768020 bytes
Database Buffers          746586112 bytes
Redo Buffers                4644864 bytes
数据库装载完毕。
ORA-01122: 数据库文件 1 验证失败
ORA-01110: 数据文件 1: 'D:\APP\ADMINISTRATOR\ORADATA\ORCL\SYSTEM01.DBF'
ORA-01200: 87946 的实际文件大小小于 88320 块的正确大小

这里的错误很明显是因为file 1的数据文件头记录block大小为88320个block,而该数据文件的实际大小只有87946个block,所以出现该问题.

dbv检测文件

D:\app\Administrator\oradata\orcl>dbv file=SYSTEM01.DBF

DBVERIFY: Release 11.1.0.6.0 - Production on 星期日 5月 12 22:30:29 2013

Copyright (c) 1982, 2007, Oracle.  All rights reserved.

DBVERIFY - 开始验证: FILE = SYSTEM01.DBF


DBVERIFY - 验证完成

检查的页总数: 87040
处理的页总数 (数据): 62870
失败的页总数 (数据): 0
处理的页总数 (索引): 11055
失败的页总数 (索引): 0
处理的页总数 (其它): 2437
处理的总页数 (段)  : 0
失败的总页数 (段)  : 0
空的页总数: 10678
标记为损坏的总页数: 0
流入的页总数: 0
加密的总页数        : 0
最高块 SCN            : 980055 (0.980055)

检查发现该数据文件未发现坏块,减小了该数据文件通过bbed恢复异常的风险,数据库最怕就是system中出现很多坏块

使用bbed修改kccfhfsz
因为win的bbed问题,所以拷贝到我的电脑上进行修改

C:\Users\XIFENFEI\Desktop\temp>bbed filename=system01.dbf blocksize=8192
Password:

BBED: Release 2.0.0.0.0 - Limited Production on Sun May 12 23:27:26 2013

Copyright (c) 1982, 2002, Oracle Corporation.  All rights reserved.

************* !!! For Oracle Internal Use only !!! ***************

BBED> set block 2
        BLOCK#          2
--从一台机器中拷贝到另外的机器,实际中的block可能发生改变,因为含block 0

BBED> map
 File: system01.dbf (0)
 Block: 2                                     Dba:0x00000000
------------------------------------------------------------
 Data File Header

 struct kcvfh, 360 bytes                    @0

 ub4 tailchk                                @8188


BBED> p kcvfhhdr.kccfhfsz
ub4 kccfhfsz                                @44       0x0001578a

--通过ORA-01200错误报出来的文件头记录大小88320实际就是0x0001578a


BBED> set mode edit
        MODE            Edit

BBED> set count 32
        COUNT           32

BBED> d
 File: system01.dbf (0)
 Block: 2                Offsets:   44 to   75           Dba:0x00000000
------------------------------------------------------------------------
00590100 00200000 01000300 00000000 00000000 00000000 00000000 00000000

 <32 bytes per line>

BBED> m /x 8A570100
 File: system01.dbf (0)
 Block: 2                Offsets:   44 to   75           Dba:0x00000000
------------------------------------------------------------------------
 8a570100 00200000 01000300 00000000 00000000 00000000 00000000 00000000

 <32 bytes per line>
--通过ORA-01200错误报出来的数据文件实际大小,来修改该文件头的kcvfhhdr.kccfhfsz值,也可以通过文件实际大小计算出来


BBED> p kcvfhhdr.kccfhfsz
ub4 kccfhfsz                                @44       0x0001578a

BBED> sum apply
Check value for File 0, Block 2:
current = 0x0f79, required = 0x0f79

BBED> verify
DBVERIFY - Verification starting
FILE = system01.dbf
BLOCK = 1


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   : 0
Total Blocks Influx           : 0

打开数据库

SQL> select open_mode from v$database;

OPEN_MODE
----------
MOUNTED

SQL> alter database open;

数据库已更改。
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bbed模拟提交事务二之屏蔽smon回滚事务

在上一篇修改datablock itl(bbed模拟提交事务一之修改itl)的基础之上,本篇实现修改undo segment header中的相关事务槽信息,从而屏蔽数据库在重启或者进程异常的时候,smon的回滚操作,从而比较完美的实现了手工提交数据库事务
update table and uncommit(session 1)

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

   REL_FNO   BLOCK_NO
---------- ----------
         4         28

SQL> select * from chf.t_xifenfei;

 OBJECT_ID OBJECT_NAME
---------- --------------------
        20 xifenfei.com
        44 xifenfei.com
        28 xifenfei.com
        15 xifenfei.com
        29 xifenfei.com
         3 xifenfei.com
        25 xifenfei.com
        39 xifenfei.com
        51 xifenfei.com
        26 xifenfei.com
        17 xifenfei.com
        13 xifenfei.com
         9 xifenfei.com
        41 xifenfei.com
        48 I_CON1
        38 I_OBJ3
         7 I_TS#
        53 I_CDEF4
        19 IND$

19 rows selected.

SQL> update chf.t_xifenfei set object_name='orasos.com' where rownum<10;

9 rows updated.

SQL> select * from chf.t_xifenfei;

 OBJECT_ID OBJECT_NAME
---------- --------------------
        20 orasos.com
        44 orasos.com
        28 orasos.com
        15 orasos.com
        29 orasos.com
         3 orasos.com
        25 orasos.com
        39 orasos.com
        51 orasos.com
        26 xifenfei.com
        17 xifenfei.com
        13 xifenfei.com
         9 xifenfei.com
        41 xifenfei.com
        48 I_CON1
        38 I_OBJ3
         7 I_TS#
        53 I_CDEF4
        19 IND$

19 rows selected.

dump undo header(session 2)

SQL> alter system flush buffer_cache;

System altered.

SQL> alter system checkpoint;

System altered.

SQL> SELECT XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBASQN,UBAREC FROM v$transaction;

    XIDUSN    XIDSLOT     XIDSQN     UBAFIL     UBABLK     UBASQN     UBAREC
---------- ---------- ---------- ---------- ---------- ---------- ----------
         1         13        367          2       1126        362         32

SQL>  alter system dump undo header "_SYSSMU1$";

System altered.


index  state cflags  wrap#    uel         scn            dba     parent-xid          nub       stmt_num       cmt
------------------------------------------------------------------------------------------------------------------
   …………
0x0c    9    0x00  0x016e  0x0029  0x0b2c.c02d1f6a  0x00800464  0x0000.000.00000000  0x00000001   0x00000000  1358813163
0x0d   10    0x80  0x016f  0x0002  0x0b2c.c02d7b15  0x00800466  0x0000.000.00000000  0x00000001   0x00000000  0
0x0e    9    0x00  0x016f  0x000f  0x0b2c.c02d2ae2  0x00800466  0x0000.000.00000000  0x00000001   0x00000000  1358820065
   …………

通过结合dump undo header 中的TRN TBL的state为10的为active事务,然后结合scn/dba等信息,
来确定是哪条记录是需要我们修改.然后通过find命令快速定位到0x0d这条记录,然后进行修改

通过结合bbed的dump命令得出16进制数据分析得出如下结论

--index 0x0c
6e01        0000 64048000      6a1f2dc0 2c0b0000      09       00          2900      
0000000000000000            00000000          01000000     ebd7fd50(1358813163注意存储顺序)

--index 0x0d
6f01  wrap# 0000 66048000 dba  157b2dc0 2c0b0000 scn  0a state 80  cflags  0200 uel  
0000000000000000 parent-xid 00000000 stmt_num 01000000 nub 00000000 cmt

--index 0x0e
6f01        0000 66048000      e22a2dc0 2c0b0000      09       00          0f00      
0000000000000000            00000000          01000000     e1f2fd50(1358820065)

bbed modify undo segment header(session 2)

BBED> f /x 0a80
 File: /u01/oracle/oradata/XFF/undotbs01.dbf (0)
 Block: 9                Offsets: 6736 to 6751           Dba:0x00000000
------------------------------------------------------------------------
 0a800200 00000000 00000000 00000000 

 <32 bytes per line>

BBED> m /x 0900
Warning: contents of previous BIFILE will be lost. Proceed? (Y/N) y
 File: /u01/oracle/oradata/XFF/undotbs01.dbf (0)
 Block: 9                Offsets: 6736 to 6751           Dba:0x00000000
------------------------------------------------------------------------
 09000200 00000000 00000000 00000000  

 <32 bytes per line>

BBED> sum apply
Check value for File 0, Block 9:
current = 0xecdd, required = 0xecdd

bbed modify data block itl(session 2)

struct ktbbhitl[0], 24 bytes             @44      
      struct ktbitxid, 8 bytes              @44      
         ub2 kxidusn                        @44       0x0001
         ub2 kxidslt                        @46       0x000d
         ub4 kxidsqn                        @48       0x0000016f
      struct ktbituba, 8 bytes              @52      
         ub4 kubadba                        @52       0x00800466
         ub2 kubaseq                        @56       0x016a
         ub1 kubarec                        @58       0x20
      ub2 ktbitflg                          @60       0x0009 (NONE)
      union _ktbitun, 2 bytes               @62      
         b2 _ktbitfsc                       @62       18
         ub2 _ktbitwrp                      @62       0x0012
      ub4 ktbitbas                          @64       0x00000000

BBED> m /x 0080 offset 60
Warning: contents of previous BIFILE will be lost. Proceed? (Y/N) y
 File: /u01/oracle/oradata/XFF/users01.dbf (0)
 Block: 28               Offsets:   60 to  571           Dba:0x00000000
------------------------------------------------------------------------
 00801200 00000000 09002a00 36020000  

 <32 bytes per line>

BBED> sum apply
Check value for File 0, Block 28:
current = 0xccf1, required = 0xccf1

restart db and select table(session 3)

SQL> shutdown abort
ORACLE instance shut down.
SQL> startup
ORACLE instance started.

Total System Global Area  306184192 bytes
Fixed Size                  1267164 bytes
Variable Size             109054500 bytes
Database Buffers          188743680 bytes
Redo Buffers                7118848 bytes
Database mounted.
Database opened.
SQL> col object_name for a20
SQL> set pages 100
SQL> select * from chf.t_xifenfei;

 OBJECT_ID OBJECT_NAME
---------- --------------------
        20 orasos.com
        44 orasos.com
        28 orasos.com
        15 orasos.com
        29 orasos.com
         3 orasos.com
        25 orasos.com
        39 orasos.com
        51 orasos.com
        26 xifenfei.com
        17 xifenfei.com
        13 xifenfei.com
         9 xifenfei.com
        41 xifenfei.com
        48 I_CON1
        38 I_OBJ3
         7 I_TS#
        53 I_CDEF4
        19 IND$

19 rows selected.

到此证明,通过修改undo segment header中的state和cflags实现数据库启动不回滚未提交事务;通过修改datablock itl实现数据库在访问未提交数据块时候不访问undo。从而整体上较完美的实现了手工提交一个事务(数据库提交一个事务涉及的方方面面较为复杂,这里只是通过修改最核心的两部分来大致模拟提交事务)

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bbed模拟提交事务一之修改itl

我们都知道,根据oracle 事务的一致性,当我们在session 1中进行dml操作,如果未提交在其他会话中是无法看到修改后的值(只能看到修改前的值).这里通过bbed模拟部分提交事务从而实现在其他会话中查看到另外会话未提交事务(本质已经部分模拟提交,还有undo segment header中信息未清理,下篇补充)
create table(session 1)

SQL> create table chf.t_xifenfei
  2  as
  3  select object_id,object_name from dba_objects where rownum<20;

Table created.

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

ROWID                 REL_FNO   BLOCK_NO
------------------ ---------- ----------
AAANL3AAEAAAAAcAAA          4         28
AAANL3AAEAAAAAcAAB          4         28
AAANL3AAEAAAAAcAAC          4         28
AAANL3AAEAAAAAcAAD          4         28
AAANL3AAEAAAAAcAAE          4         28
AAANL3AAEAAAAAcAAF          4         28
AAANL3AAEAAAAAcAAG          4         28
AAANL3AAEAAAAAcAAH          4         28
AAANL3AAEAAAAAcAAI          4         28
AAANL3AAEAAAAAcAAJ          4         28
AAANL3AAEAAAAAcAAK          4         28
AAANL3AAEAAAAAcAAL          4         28
AAANL3AAEAAAAAcAAM          4         28
AAANL3AAEAAAAAcAAN          4         28
AAANL3AAEAAAAAcAAO          4         28
AAANL3AAEAAAAAcAAP          4         28
AAANL3AAEAAAAAcAAQ          4         28
AAANL3AAEAAAAAcAAR          4         28
AAANL3AAEAAAAAcAAS          4         28

19 rows selected.

SQL>  select * from chf.t_xifenfei;

 OBJECT_ID OBJECT_NAME
---------- --------------------
        20 ICOL$
        44 I_USER1
        28 CON$
        15 UNDO$
        29 C_COBJ#
         3 I_OBJ#
        25 PROXY_ROLE_DATA$
        39 I_IND1
        51 I_CDEF2
        26 I_PROXY_ROLE_DATA$_1
        17 FILE$
        13 UET$
         9 I_FILE#_BLOCK#
        41 I_FILE1
        48 I_CON1
        38 I_OBJ3
         7 I_TS#
        53 I_CDEF4
        19 IND$

19 rows selected.

dump block(session 2)

SQL> alter system checkpoint;

System altered.

SQL> alter system dump datafile 4 block 28;

System altered.

 
 Itl           Xid                  Uba         Flag  Lck        Scn/Fsc
0x01   0xffff.000.00000000  0x00000000.0000.00  C---    0  scn 0x0b2c.c02d1987
0x02   0x0000.000.00000000  0x00000000.0000.00  ----    0  fsc 0x0000.00000000
0x03   0x0000.000.00000000  0x00000000.0000.00  ----    0  fsc 0x0000.00000000

update record(session 1)

SQL> update chf.t_xifenfei set object_name ='www.xifenfei.com' where rownum<15;

14 rows updated.

SQL> col object_name for a20
SQL> select * from chf.t_xifenfei;

 OBJECT_ID OBJECT_NAME
---------- --------------------
        20 www.xifenfei.com
        44 www.xifenfei.com
        28 www.xifenfei.com
        15 www.xifenfei.com
        29 www.xifenfei.com
         3 www.xifenfei.com
        25 www.xifenfei.com
        39 www.xifenfei.com
        51 www.xifenfei.com
        26 www.xifenfei.com
        17 www.xifenfei.com
        13 www.xifenfei.com
         9 www.xifenfei.com
        41 www.xifenfei.com
        48 I_CON1
        38 I_OBJ3
         7 I_TS#
        53 I_CDEF4
        19 IND$

19 rows selected.

dump block(session 2)

SQL> alter system checkpoint;

System altered.

--注意flush buffer_cache(不然后面bbed修改会被不能通过select显示,而且会被覆盖)
SQL> alter system flush buffer_cache;

System altered.

SQL>  alter system flush shared_pool;

System altered.

SQL> alter system dump datafile 4 block 28;

System altered.

 Itl           Xid                  Uba         Flag  Lck        Scn/Fsc
0x01   0xffff.000.00000000  0x00000000.0000.00  C---    0  scn 0x0b2c.c02d1987
0x02   0x000a.00a.0000017e  0x0081ffc7.01a2.22  ----   14  fsc 0x0000.00000000  <--注意Lck 14
0x03   0x0000.000.00000000  0x00000000.0000.00  ----    0  fsc 0x0000.00000000

bbed commit Transaction(session 3)

BBED> p ktbbh
struct ktbbh, 96 bytes                      @20      
   ub1 ktbbhtyp                             @20       0x01 (KDDBTDATA)
   union ktbbhsid, 4 bytes                  @24      
      ub4 ktbbhsg1                          @24       0x0000d2f7
      ub4 ktbbhod1                          @24       0x0000d2f7
   struct ktbbhcsc, 8 bytes                 @28      
      ub4 kscnbas                           @28       0xc02d1aec
      ub2 kscnwrp                           @32       0x0b2c
   b2 ktbbhict                              @36       3
   ub1 ktbbhflg                             @38       0x32 (NONE)
   ub1 ktbbhfsl                             @39       0x00
   ub4 ktbbhfnx                             @40       0x01000019
   struct ktbbhitl[0], 24 bytes             @44      
      struct ktbitxid, 8 bytes              @44      
         ub2 kxidusn                        @44       0xffff
         ub2 kxidslt                        @46       0x0000
         ub4 kxidsqn                        @48       0x00000000
      struct ktbituba, 8 bytes              @52      
         ub4 kubadba                        @52       0x00000000
         ub2 kubaseq                        @56       0x0000
         ub1 kubarec                        @58       0x00
      ub2 ktbitflg                          @60       0x8000 (KTBFCOM)
      union _ktbitun, 2 bytes               @62      
         b2 _ktbitfsc                       @62       2860
         ub2 _ktbitwrp                      @62       0x0b2c
      ub4 ktbitbas                          @64       0xc02d1987
   struct ktbbhitl[1], 24 bytes             @68      
      struct ktbitxid, 8 bytes              @68      
         ub2 kxidusn                        @68       0x000a
         ub2 kxidslt                        @70       0x000a
         ub4 kxidsqn                        @72       0x0000017e
      struct ktbituba, 8 bytes              @76      
         ub4 kubadba                        @76       0x0081ffc7
         ub2 kubaseq                        @80       0x01a2
         ub1 kubarec                        @82       0x22
      ub2 ktbitflg                          @84       0x000e (NONE) <--修改要改为8000
      union _ktbitun, 2 bytes               @86      
         b2 _ktbitfsc                       @86       0
         ub2 _ktbitwrp                      @86       0x0000
      ub4 ktbitbas                          @88       0x00000000
   struct ktbbhitl[2], 24 bytes             @92      
      struct ktbitxid, 8 bytes              @92      
         ub2 kxidusn                        @92       0x0000
         ub2 kxidslt                        @94       0x0000
         ub4 kxidsqn                        @96       0x00000000
      struct ktbituba, 8 bytes              @100     
         ub4 kubadba                        @100      0x00000000
         ub2 kubaseq                        @104      0x0000
         ub1 kubarec                        @106      0x00
      ub2 ktbitflg                          @108      0x0000 (NONE)
      union _ktbitun, 2 bytes               @110     
         b2 _ktbitfsc                       @110      0
         ub2 _ktbitwrp                      @110      0x0000
      ub4 ktbitbas                          @112      0x00000000

BBED> m /x 0080 offset 84
Warning: contents of previous BIFILE will be lost. Proceed? (Y/N) y
 File: /u01/oracle/oradata/XFF/users01.dbf (0)
 Block: 28               Offsets:   84 to  115           Dba:0x00000000
------------------------------------------------------------------------
 00800000 00000000 00000000 00000000  

 <32 bytes per line>

BBED> sum apply
Check value for File 0, Block 28:
current = 0x03dc, required = 0x03dc


BBED> p ktbbh
struct ktbbh, 96 bytes                      @20      
  …………
   struct ktbbhitl[1], 24 bytes             @68      
      struct ktbitxid, 8 bytes              @68      
         ub2 kxidusn                        @68       0x000a
         ub2 kxidslt                        @70       0x000a
         ub4 kxidsqn                        @72       0x0000017e
      struct ktbituba, 8 bytes              @76      
         ub4 kubadba                        @76       0x0081ffc7
         ub2 kubaseq                        @80       0x01a2
         ub1 kubarec                        @82       0x22
      ub2 ktbitflg                          @84       0x8000 (KTBFCOM) <--修改值
      union _ktbitun, 2 bytes               @86      
         b2 _ktbitfsc                       @86       0
         ub2 _ktbitwrp                      @86       0x0000
      ub4 ktbitbas                          @88       0x00000000
  …………

dump block(session 2)

SQL> alter system dump datafile 4 block 28;

System altered.

 Itl           Xid                  Uba         Flag  Lck        Scn/Fsc
0x01   0xffff.000.00000000  0x00000000.0000.00  C---    0  scn 0x0b2c.c02d1987
0x02   0x000a.00a.0000017e  0x0081ffc7.01a2.22  C---    0  scn 0x0000.00000000
0x03   0x0000.000.00000000  0x00000000.0000.00  ----    0  fsc 0x0000.00000000

select data(session 4)

SQL> select object_id,object_name from chf.t_xifenfei;

 OBJECT_ID OBJECT_NAME
---------- --------------------
        20 www.xifenfei.com
        44 www.xifenfei.com
        28 www.xifenfei.com
        15 www.xifenfei.com
        29 www.xifenfei.com
         3 www.xifenfei.com
        25 www.xifenfei.com
        39 www.xifenfei.com
        51 www.xifenfei.com
        26 www.xifenfei.com
        17 www.xifenfei.com
        13 www.xifenfei.com
         9 www.xifenfei.com
        41 www.xifenfei.com
        48 I_CON1
        38 I_OBJ3
         7 I_TS#
        53 I_CDEF4
        19 IND$

19 rows selected.

这里可以看到,已经模拟出来在其他session中可以访问数据库为commit的记录(在该block级别已经模拟了commit)

发表在 Oracle | 标签为 , | 2 条评论