[20161111]数据库文件头的修复.txt
--这里指文件头实际上数据文件第1块(从0算起)。
--找到一个链接，http://www.cnblogs.com/hrhguanli/p/4708273.html
--要修改的信息相对较多。
1 .改动数据的DBA,rdba_kcbh
2 .改动文件的大小，kccfhfsz
3 .改动文件号，kccfhfno
4 .改动文件创建时SCN，kcvfhcrs
5 .改动文件创建时间，kcvfhcrt
6 .改动表空间号，kcvfhtsn
7 .改动相对文件号，kcvfhrfn
8 .改动表空间的名称， kcvfhtnm
9 .改动表空间的长度，kcvfhtln
10.改动检查点的SCN，kcvfhckp
11.改动检查点的时间，kcvcptim
12.改动检查点的计数器，kcvfhcpc
13.改动检查点的控制文件备份的计数器， kcvfhccc
14.假设你改动是1号文件的1号块他的root rdba针指向bootstrap$
--实际上修改没有这么多，不过还是按照这个过程操作修改内容。
1.环境：
SCOTT@book> @ &r/ver1
PORT_STRING VERSION BANNER
------------------------------ -------------- --------------------------------------------------------------------------------
x86_64/Linux 2.4.xx 11.2.0.4.0 Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production
CREATE TABLESPACE SUGAR DATAFILE
'/mnt/ramdisk/book/sugar01.dbf' SIZE 40M AUTOEXTEND ON NEXT 16M MAXSIZE UNLIMITED
LOGGING
ONLINE
EXTENT MANAGEMENT LOCAL AUTOALLOCATE
BLOCKSIZE 8K
SEGMENT SPACE MANAGEMENT AUTO
FLASHBACK ON;
create table t1 tablespace sugar as select rownum id ,lpad('A',32,'A') name from dual connect by level<=1e5;
--建立大小5M的表。
alter system checkpoint;
alter system checkpoint;
...
alter system checkpoint;
CREATE TABLESPACE TEA DATAFILE
'/mnt/ramdisk/book/tea01.dbf' SIZE 40M AUTOEXTEND ON NEXT 16M MAXSIZE UNLIMITED
LOGGING
ONLINE
EXTENT MANAGEMENT LOCAL AUTOALLOCATE
BLOCKSIZE 8K
SEGMENT SPACE MANAGEMENT AUTO
FLASHBACK ON;
alter system checkpoint;
--建立的数据文件大小一致，可以减少一些修改内容。执行alter system checkpoint;这样可以导致2个文件的改动检查点的计数器不同。
SCOTT@book> alter database datafile 6 offline ;
Database altered.
SCOTT@book> alter database datafile 7 offline ;
Database altered.
--做这种offline，最好顺手做一个recover datafile N，避免时间上了online时要recover没有归档文件。当然这里测试不需要。
SCOTT@book> SELECT file#, CHECKPOINT_CHANGE#, CHECKPOINT_TIME,CREATION_CHANGE# , RESETLOGS_CHANGE#,status, CHECKPOINT_COUNT,fuzzy,name,tablespace_name FROM v$datafile_header;
FILE# CHECKPOINT_CHANGE# CHECKPOINT_TIME CREATION_CHANGE# RESETLOGS_CHANGE# STATUS CHECKPOINT_COUNT FUZ NAME TABLESPACE_NAME
----- ------------------ ------------------- ---------------- ----------------- ------- ---------------- --- ------------------------------- ----------------
1 6317588 2016-11-11 15:08:38 7 2002065 ONLINE 419 YES /mnt/ramdisk/book/system01.dbf SYSTEM
2 6317588 2016-11-11 15:08:38 1834 2002065 ONLINE 416 YES /mnt/ramdisk/book/sysaux01.dbf SYSAUX
3 6317588 2016-11-11 15:08:38 923328 2002065 ONLINE 337 YES /mnt/ramdisk/book/undotbs01.dbf UNDOTBS1
4 6317588 2016-11-11 15:08:38 16143 2002065 ONLINE 415 YES /mnt/ramdisk/book/users01.dbf USERS
5 6317588 2016-11-11 15:08:38 952916 2002065 ONLINE 335 YES /mnt/ramdisk/book/example01.dbf EXAMPLE
6 6317503 2016-11-11 15:07:28 6316871 2002065 OFFLINE 3 NO /mnt/ramdisk/book/sugar01.dbf SUGAR
7 6317588 2016-11-11 15:08:38 6317214 2002065 OFFLINE 11 YES /mnt/ramdisk/book/tea01.dbf TEA
7 rows selected.
2.备份数据文件6.
$ cp /mnt/ramdisk/book/sugar01.dbf /u01/backup/sugar01.dbf_20161110
$ bvi -b 8192 -s 8192 /mnt/ramdisk/book/sugar01.dbf
--全部置为0
$ dd if=/dev/zero of=/mnt/ramdisk/book/sugar01.dbf count=1 bs=8192 conv=notrunc seek=1
1+0 records in
1+0 records out
8192 bytes (8.2 kB) copied, 4.0611e-05 seconds, 202 MB/s
BBED> copy dba 7,1 to dba 6,1
Warning: contents of previous BIFILE will be lost. Proceed? (Y/N) y
File: /mnt/ramdisk/book/sugar01.dbf (6)
Block: 1 Offsets: 0 to 255 Dba:0x01800001
------------------------------------------------------------------------------------------------------------------------------------------------
0ba20000 0100c001 00000000 00000104 c54f0000 00000000 0004200b 6e21b74f 424f4f4b 00000000 fc6b0000 00140000 00200000 07000300 00000000 00000000
00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 9e646000 00000000 68bc4a37 e6702c37 918c1e00 00000000 00000000
00000000 00000000 00000400 0b000000 cabc4a37 0a000000 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
<64 bytes per line>
--这样使用数据文件7的文件头替换了数据文件6的文件头。
3.开始修改。
1.改动数据的DBA,rdba_kcbh
BBED> set dba 6,1
DBA 0x01800001 (25165825 6,1)
BBED> p dba 6,1 kcvfh.kcvfhbfh.rdba_kcbh
ub4 rdba_kcbh @4 0x01c00001
BBED> assign dba 6,1 kcvfh.kcvfhbfh.rdba_kcbh = 0x01800001
ub4 rdba_kcbh @4 0x01800001
--查看执行set dba 6,1的输出就知道dba地址。
2 .改动文件的大小，kccfhfsz
--这个忽略，大小一样。
BBED> p dba 6,1 kcvfh.kcvfhhdr.kccfhfsz
ub4 kccfhfsz @44 0x00001400
-- 0x1400 = 5120, 5120*8192/1024/1024=40M
3 .改动文件号，kccfhfno
BBED> p dba 6,1 kcvfh.kcvfhhdr.kccfhfno
ub2 kccfhfno @52 0x0007
BBED> assign dba 6,1 kcvfh.kcvfhhdr.kccfhfno=0x0006
ub2 kccfhfno @52 0x0006
4 .改动文件创建时SCN，kcvfhcrs
SCOTT@book> SELECT CREATION_CHANGE#,CREATION_TIME ,file#,NAME from v$datafile where file#=6 or file#=7;
CREATION_CHANGE# CREATION_TIME FILE# NAME
---------------- ------------------- ----- --------------------------------------------------
6316871 2016-11-11 15:05:44 6 /mnt/ramdisk/book/sugar01.dbf
6317214 2016-11-11 15:06:16 7 /mnt/ramdisk/book/tea01.dbf
BBED> p /d dba 6,1 kcvfh.kcvfhhdr.kcvfhcrs
struct kcvfhcrs, 8 bytes @100
ub4 kscnbas @100 6317214
ub2 kscnwrp @104 0
BBED> assign dba 6,1 kcvfh.kcvfhhdr.kcvfhcrs.kscnbas=6316871
ub4 kscnbas @100 0x00606347
5 .改动文件创建时间，kcvfhcrt
SCOTT@book> SELECT CREATION_CHANGE#,CREATION_TIME ,file#,NAME from v$datafile where file#=6 or file#=7;
CREATION_CHANGE# CREATION_TIME FILE# NAME
---------------- ------------------- ----- --------------------------------------------------
6316871 2016-11-11 15:05:44 6 /mnt/ramdisk/book/sugar01.dbf
6317214 2016-11-11 15:06:16 7 /mnt/ramdisk/book/tea01.dbf
BBED> p /d dba 6,1 kcvfh.kcvfhhdr.kcvfhcrt
ub4 kcvfhcrt @108 927644776
--注意现在file#=7的时间。
SCOTT@book> select (to_date('2016-11-11 15:06:16','yyyy-mm-dd hh24:mi:ss')-to_date('2016-11-11 15:05:44','yyyy-mm-dd hh24:mi:ss'))*86400 N10 from dual;
N10
---------------------
32
-- 927644776-32=927644744
BBED> assign dba 6,1 kcvfh.kcvfhhdr.kcvfhcrt=927644744
ub4 kcvfhcrt @108 0x374abc48
--补充说明：第4，5步我开始忽略，我认为可以不改。但是实际上在recover时报错。
SCOTT@book> recover datafile 6;
ORA-00283: recovery session canceled due to errors
ORA-01110: data file 6: '/mnt/ramdisk/book/sugar01.dbf'
ORA-01122: database file 6 failed verification check
ORA-01110: data file 6: '/mnt/ramdisk/book/sugar01.dbf'
ORA-01202: wrong incarnation of this file - wrong creation time
6 .改动表空间号，kcvfhtsn
SCOTT@book> select ts#,name from sys.ts$ where name in ('SUGAR','TEA');
TS# NAME
------------ --------------------------------------------------
7 SUGAR
8 TEA
BBED> p dba 6,1 kcvfh.kcvfhhdr.kcvfhtsn
sword kcvfhtsn @332 8
BBED> assign dba 6,1 kcvfh.kcvfhhdr.kcvfhtsn=7
sword kcvfhtsn @332 7
7 .改动相对文件号，kcvfhrfn
BBED> p dba 6,1 kcvfh.kcvfhhdr.kcvfhrfn
ub4 kcvfhrfn @368 0x00000007
BBED> assign dba 6,1 kcvfh.kcvfhhdr.kcvfhrfn=0x00000006
ub4 kcvfhrfn @368 0x00000006
8 .改动表空间的名称， kcvfhtnm
BBED> p /c dba 6,1 kcvfh.kcvfhhdr.kcvfhtnm
text kcvfhtnm[0] @338 T
text kcvfhtnm[1] @339 E
text kcvfhtnm[2] @340 A
text kcvfhtnm[3] @341 .
text kcvfhtnm[4] @342 .
SCOTT@book> select dump('S',16) from dual ;
DUMP('S',16)
----------------
Typ=96 Len=1: 53
BBED> assign dba 6,1 kcvfh.kcvfhhdr.kcvfhtnm[0]=0x53
text kcvfhtnm[0] @338 S
BBED> assign dba 6,1 kcvfh.kcvfhhdr.kcvfhtnm[1]=0x55
text kcvfhtnm[0] @339 U
BBED> assign dba 6,1 kcvfh.kcvfhhdr.kcvfhtnm[2]=0x47
text kcvfhtnm[0] @340 G
BBED> assign dba 6,1 kcvfh.kcvfhhdr.kcvfhtnm[3]=0x41
text kcvfhtnm[0] @341 A
BBED> assign dba 6,1 kcvfh.kcvfhhdr.kcvfhtnm[4]=0x52
text kcvfhtnm[0] @343 R
--检查略。
9 .改动表空间的长度，kcvfhtln
BBED> p dba 6,1 kcvfh.kcvfhhdr.kcvfhtln
ub2 kcvfhtln @336 0x0003
BBED> assign dba 6,1 kcvfh.kcvfhhdr.kcvfhtln=0x0005
ub2 kcvfhtln @336 0x0005
--修改长度5，SUGAR占5个字符。
10.改动检查点的SCN，kcvfh.kcvfhhdr.kcvfhckp.kcvcpscn
SCOTT@book> SELECT file#, CHECKPOINT_CHANGE#,CHECKPOINT_TIME,UNRECOVERABLE_CHANGE#,UNRECOVERABLE_TIME,LAST_CHANGE#,LAST_TIME, OFFLINE_CHANGE#, ONLINE_CHANGE#,status,name FROM v$datafile where file#=6;
FILE# CHECKPOINT_CHANGE# CHECKPOINT_TIME UNRECOVERABLE_CHANGE# UNRECOVERABLE_TIME LAST_CHANGE# LAST_TIME OFFLINE_CHANGE# ONLINE_CHANGE# STATUS NAME
----- ------------------ ------------------- --------------------- ------------------- ------------ ------------------- --------------- -------------- ------- --------------------------------------------------
6 6317503 2016-11-11 15:07:28 0 6317503 2016-11-11 15:07:28 0 0 OFFLINE /mnt/ramdisk/book/sugar01.dbf
BBED> p /d dba 6,1 kcvfh.kcvfhhdr.kcvfhckp.kcvcpscn
struct kcvcpscn, 8 bytes @484
ub4 kscnbas @484 6317588
ub2 kscnwrp @488 0
BBED> assign /d dba 6,1 kcvfh.kcvfhhdr.kcvfhckp.kcvcpscn.kscnbas=6317503
ub4 kscnbas @484 0x006065bf
11.改动检查点的时间，kcvcptim
BBED> p /d dba 6,1 kcvfh.kcvfhhdr.kcvfhckp.kcvcptim
ub4 kcvcptim @492 927644918
SCOTT@book> SELECT file#, CHECKPOINT_CHANGE#,CHECKPOINT_TIME,UNRECOVERABLE_CHANGE#,UNRECOVERABLE_TIME,LAST_CHANGE#,LAST_TIME, OFFLINE_CHANGE#, ONLINE_CHANGE#,status,name FROM v$datafile where file# in (6,7);
FILE# CHECKPOINT_CHANGE# CHECKPOINT_TIME UNRECOVERABLE_CHANGE# UNRECOVERABLE_TIME LAST_CHANGE# LAST_TIME OFFLINE_CHANGE# ONLINE_CHANGE# STATUS NAME
----- ------------------ ------------------- --------------------- ------------------- ------------ ------------------- --------------- -------------- ------- --------------------------------------------------
6 6317503 2016-11-11 15:07:28 0 6317503 2016-11-11 15:07:28 0 0 OFFLINE /mnt/ramdisk/book/sugar01.dbf
7 6317588 2016-11-11 15:08:38 0 6317624 2016-11-11 15:10:02 0 0 RECOVER /mnt/ramdisk/book/tea01.dbf
--注意现在file#=7的时间。
SCOTT@book> select (to_date('2016-11-11 15:08:38','yyyy-mm-dd hh24:mi:ss')-to_date('2016-11-11 15:07:28','yyyy-mm-dd hh24:mi:ss'))*86400 N10 from dual;
N10
---------------------
70
--927644918-70=927644848
BBED> assign /d dba 6,1 kcvfh.kcvfhhdr.kcvfhckp.kcvcptim=927644848
ub4 kcvcptim @492 0x374abcb0
12.改动检查点的计数器，kcvfhcpc
--如果你看前面的查询v$datafile_header;CHECKPOINT_COUNT=3,现在是11.
BBED> p /d dba 6,1 kcvfh.kcvfhrdb.kcvfhcpc
ub4 kcvfhcpc @140 11
--这个信息来源于控制文件，你可以转储alter session set events 'immediate trace name controlf level 12';
DATA FILE #6:
name #10: /mnt/ramdisk/book/sugar01.dbf
creation size=5120 block size=8192 status=0xc head=10 tail=10 dup=1
tablespace 7, index=7 krfil=6 prev_file=0
unrecoverable scn: 0x0000.00000000 01/01/1988 00:00:00
Checkpoint cnt:3 scn: 0x0000.006065bf 11/11/2016 15:07:28
Stop scn: 0x0000.006065bf 11/11/2016 15:07:28
Creation Checkpointed at scn: 0x0000.00606347 11/11/2016 15:05:44
thread:1 rba:(0x9f.5897.10)
enabled threads: 01000000 00000000 00000000 00000000 00000000 00000000
00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
BBED> p /d dba 6,1 kcvfh.kcvfhrdb.kcvfhcpc
ub4 kcvfhcpc @140 11
BBED> assign /d dba 6,1 kcvfh.kcvfhrdb.kcvfhcpc=2
ub4 kcvfhcpc @140 0x00000002
13.改动检查点的控制文件备份的计数器， kcvfhccc
--就是比减少kcvfhcpc-1
BBED> p /d dba 6,1 kcvfh.kcvfhrdb.kcvfhccc
ub4 kcvfhccc @148 10
BBED> assign /d dba 6,1 kcvfh.kcvfhrdb.kcvfhccc=1
ub4 kcvfhccc @148 0x00000001
--先这样修改看看。
--补充说明，我开始没改，但是执行recover时报错。估计这个是11太大，我设置比原来的3小就ok了。
SCOTT@book> recover datafile 6;
ORA-00283: recovery session canceled due to errors
ORA-01122: database file 6 failed verification check
ORA-01110: data file 6: '/mnt/ramdisk/book/sugar01.dbf'
ORA-01207: file is more recent than control file - old control file
14.假设你改动是1号文件的1号块他的root rdba针指向bootstrap$
--不是系统文件，这个不修改了。
BBED> p dba 1,1 kcvfh.kcvfhrdb
ub4 kcvfhrdb @96 0x00400208
BBED> p dba 6,1 kcvfh.kcvfhrdb
ub4 kcvfhrdb @96 0x00000000
BBED> set dba 0x00400208
DBA 0x00400208 (4194824 1,520)
--这个位置在dba=1,520,大家可以自行验证。
SCOTT@book> @ &r/which_obj 1 520
OWNER SEGMENT_NAME SEGMENT_TYPE TABLESPACE_NAME EXTENT_ID FILE_ID BLOCK_ID BYTES BLOCKS RELATIVE_FNO
------ -------------------- ------------------ ------------------------------ ------------ ------------ ------------ ------------ ------------ ------------
SYS BOOTSTRAP$ TABLE SYSTEM 0 1 520 65536 8 1
15.计算检查和。
BBED> sum apply dba 6,1
Check value for File 6, Block 1:
current = 0x1edf, required = 0x1edf
SCOTT@book> recover datafile 6;
ORA-00283: recovery session canceled due to errors
ORA-01110: data file 6: '/mnt/ramdisk/book/sugar01.dbf'
ORA-01122: database file 6 failed verification check
ORA-01110: data file 6: '/mnt/ramdisk/book/sugar01.dbf'
ORA-01203: wrong incarnation of this file - wrong creation SCN
16.执行恢复
SCOTT@book> recover datafile 6;
Media recovery complete.
--ok.
SCOTT@book> alter database datafile 6 online ;
Database altered.
SCOTT@book> select count(*) from t1;
COUNT(*)
------------
100000
-- 总结：
1 .改动数据的DBA,rdba_kcbh kcvfh.kcvfhbfh.rdba_kcbh
2 .改动文件的大小，kccfhfsz kcvfh.kcvfhhdr.kccfhfsz
3 .改动文件号，kccfhfno kcvfh.kcvfhhdr.kccfhfno
4 .改动文件创建时SCN，kcvfhcrs kcvfh.kcvfhhdr.kcvfhcrs
5 .改动文件创建时间，kcvfhcrt kcvfh.kcvfhhdr.kcvfhcrt
6 .改动表空间号，kcvfhtsn kcvfh.kcvfhhdr.kcvfhtsn
7 .改动相对文件号，kcvfhrfn kcvfh.kcvfhhdr.kcvfhrfn
8 .改动表空间的名称， kcvfhtnm kcvfh.kcvfhhdr.kcvfhtnm
9 .改动表空间的长度，kcvfhtln kcvfh.kcvfhhdr.kcvfhtln
10.改动检查点的SCN，kcvfhckp kcvfh.kcvfhhdr.kcvfhckp.kcvcpscn
11.改动检查点的时间，kcvcptim kcvfh.kcvfhhdr.kcvfhckp.kcvcptim
12.改动检查点的计数器，kcvfhcpc kcvfh.kcvfhrdb.kcvfhcpc
13.改动检查点的控制文件备份的计数器， kcvfhccc kcvfh.kcvfhrdb.kcvfhccc
14.假设你改动是1号文件的1号块他的root rdba针指向bootstrap$ kcvfh.kcvfhrdb
15.计算检查和。
16.千万不要在生产系统做这个测试!!
