标签归档：obet修改scn

obet一键恢复offline数据文件

发表于 2026 年 4 月 1 日由惜分飞

客户有一个数据库由于异常断电之后无法正常启动,自行尝试恢复之后但是没有open成功,让可以通过Oracle数据库异常恢复检查脚本(Oracle Database Recovery Check)脚本收集信息进行评估,发现两个问题:
1. 根据查询信息确认users01.dbf（file# 4）文件处于offline状态,而且checkpoint scn明显小于其他文件

2. 通过分析alert日志确认客户在尝试offline file 4 之后open数据库报ORA-600 4194错误,数据库没有open成功

Mon Mar 30 06:26:30 2026
Starting ORACLE instance (normal)
Mon Mar 30 06:27:00 2026
ALTER DATABASE DATAFILE 4 OFFLINE DROP
Completed: ALTER DATABASE DATAFILE 4 OFFLINE DROP
Mon Mar 30 06:27:26 2026
ALTER DATABASE OPEN
Beginning crash recovery of 1 threads
 parallel recovery started with 7 processes
Started redo scan
Completed redo scan
 read 88 KB redo, 103 data blocks need recovery
Started redo application at
 Thread 1: logseq 3, block 3
Recovery of Online Redo Log: Thread 1 Group 3 Seq 3 Reading mem 0
  Mem# 0: /home/oracle/app/oracle/oradata/orcl/redo03.log
Completed redo application of 0.07MB
Completed crash recovery at
 Thread 1: logseq 3, block 180, scn 415466134
 103 data blocks read, 103 data blocks written, 88 redo k-bytes read
Mon Mar 30 06:27:28 2026
Thread 1 advanced to log sequence 4 (thread open)
Thread 1 opened at log sequence 4
  Current log# 1 seq# 4 mem# 0: /home/oracle/app/oracle/oradata/orcl/redo01.log
Successful open of redo thread 1
MTTR advisory is disabled because FAST_START_MTTR_TARGET is not set
Mon Mar 30 06:27:28 2026
SMON: enabling cache recovery
Successfully onlined Undo Tablespace 2.
Verifying file header compatibility for 11g tablespace encryption..
Verifying 11g file header compatibility for tablespace encryption completed
SMON: enabling tx recovery
Database Characterset is ZHS16GBK
No Resource Manager plan active
Errors in file /home/oracle/app/oracle/diag/rdbms/orcl/orcl/trace/orcl_smon_17628.trc(incident=186839):
ORA-00600: internal error code, arguments: [4194], [], [], [], [], [], [], [], [], [], [], []
Incident details in: /home/oracle/app/oracle/diag/rdbms/orcl/orcl/orcl_smon_17628_i186839.trc
Exception [type: SIGBUS, Non-existent physical address] [ADDR:0x6C0C4B62] [PC:0x2297750, kgegpa()+40]
Exception [type: SIGBUS, Non-existent physical address] [ADDR:0x6C0C4B62] [PC:0x229597B, kgebse()+279]
Mon Mar 30 06:27:28 2026
PMON (ospid: 17604): terminating the instance due to error 397
Errors in file /home/oracle/app/oracle/diag/rdbms/orcl/orcl/trace/orcl_smon_17628.trc:
ORA-00328: archived log ends at change 415466135, need later change 415466136
ORA-00334: archived log: '/home/oracle/app/oracle/oradata/orcl/redo03.log'
ORA-00600: internal error code, arguments: [4194], [], [], [], [], [], [], [], [], [], [], []
Instance terminated by PMON, pid = 17604

接手这个故障之后,由于数据库是非归档模式,而且已经被屏蔽一致性强制打开过(open过程没成功),redo已经被clear过,因此基于这样的情况,直接上obet工具(Oracle Block Editor Tool修改file# 4的文件头状态
obet修复之前文件状态

STATUS	CHECKPOINT_TIME 			 FUZ CHECKPOINT_CHANGE# 	 ROW_NUM
------- ---------------------------------------- --- ------------------ ----------------
OFFLINE 2026-03-30 06:24:41			 YES	      415446014 	       1
ONLINE	2026-03-30 06:28:26			 YES	      415486184 	       7

obet修改文件头操作

OBET> open listfile.txt
Loaded 8 files from  datafile list 'listfile.txt'.

OBET> info

Loaded files (2 total):
----------------------------------------
Number  Path
----------------------------------------
     1  /home/oracle/app/oracle/oradata/orcl/system01.dbf
     4  /opt/oradata/orcl/users01.dbf
----------------------------------------

OBET> set mode edit
mode set to: edit


OBET> set file 4
filename set to: /opt/oradata/orcl/users01.dbf (file#4)

OBET> backup block 1
Created backup directory: backup_blk
Successfully backed up block 1 from current file to /tmp/backup_blk/users01.dbf_1.20260331092333


OBET> copy chkscn file 1 to file 4

Confirm Modify chkscn:
Source: file#1 (/home/oracle/app/oracle/oradata/orcl/system01.dbf)
Target: file#4 (/opt/oradata/orcl/users01.dbf)
Proceed? (Y/YES to confirm): y
Successfully copied checkpoint SCN information from file#1 to file#4.

OBET> exit
Exiting OBET.

再次查询文件头scn信息

STATUS	CHECKPOINT_TIME 			 FUZ CHECKPOINT_CHANGE# 	 ROW_NUM
------- ---------------------------------------- --- ------------------ ----------------
OFFLINE 2026-03-30 06:28:26			 NO	      415486184 	       1
ONLINE	2026-03-30 06:28:26			 YES	      415486184 	       7

尝试online文件,并open库成功

SQL> recover datafile 4;
Media recovery complete.
SQL> alter database datafile 4 online;

Database altered.

SQL> alter database open;

Database altered.

然后expdp导出数据成功,基本完成本次数据恢复工作

发表在 Oracle备份恢复 | 标签为 obet bbed, obet offline, obet修改scn | 评论关闭

obet(Oracle Block Editor Tool)第二版发布

发表于 2025 年 11 月 16 日由惜分飞

在几天之前发布了obet的第一个版本（Oracle数据块编辑工具( Oracle Block Editor Tool)-obet）,最近对功能进行了一些完善,并发布第二版
obet工具下载地址:obet下载
obet工具使用说明:obet使用说明
主要增加了以下几个功能:
0) corrupt [block x] 命令主要用于标记坏块功能(在第一版中已经完善)
1) repair [block x] 命令对于坏块的自动修复,主要包括checksum,tailchk,seq_kcbh等
2）增加copy chkscn 命令主要用于对文件头的checkpoint scn相关信息修复
3）增加copy resetlogscn命令主要用于对文件头的resetlogs相关信息修复
4）把之前的copy命令调整为copy data命令格式
5）增加copy block命令主要用于数据文件之间的数据块直接拷贝
该版本的help命令提示

OBET (Oracle Block Editor Tool) commands:
  open <config_file>    - Load file list from config file (format: <num> <path>)
  info                  - Show loaded file list (from open command)
  set filename <path>   - Set target file path (required)
  set file <num>        - Set filename using loaded file number (from open list)
  set blocksize <size>  - Set block size (2048,4096,[8192],16384,32768)
  set block <num>       - Set block number (starts from 0, default: 1)
  set offset <offset>   - Set offset within block (< blocksize, default: 0)
  set count <bytes>     - Set number of bytes to read (default: 32)
  set mode edit/browse  - Enable edit/browse mode
  d/dump [options]      - Display data (options: block X, offset Y, count N)
  m/modify <hex> [opts] - Modify data with hex (opts: block X, offset Y)
  undo                  - Undo last modification
  sum [block X]         - Calculate checksum for block (default: current block)
  sum apply [block X]   - Apply checksum: write calculated value to block
  tailchk [block X]     - Calculate tailchk for block (default: current block)
  tailchk apply [block X] - Apply tailchk: write calculated value to block
  repair [block X]      - Repair bad block (fix seq_kcbh, tailchk, checksum)
  copy data <src> to <dest>  - Copy data between files
    <src> format: file,block,offset,count (e.g., 1,1,10,64)
    <dest> format: file[,block][,offset] (e.g., 3 or 3,1 or 3,1,128)
  copy block file#,block# to file#,block#     - Copy entire data block
  copy chkscn file n to file m         - Copy datafile header checkpoint SCN info
  copy resetlogscn file n to file m    - Copy datafile header resetlogs info
  corrupt [block X]     - Mark block as corrupted (default: current block)
  show                  - Display current settings (filename, blocksize, block, offset, count, mode)
  license               - Show/manage software license (registration code required)
  version               - Show software version and developer information
  p/print <param>       - Print Oracle structure,Use the 'p/print' command to see details
  undo                  - Undo the last copy chkscn or copy resetlogscn operation
  help                  - Show this help message
  quit/exit             - Exit OBET

copy block功能演示
随便把一个block拷贝到文件的另外位置,也可以拷贝到不同文件的其他位置,根据需要调整

OBET> copy block 1,1 to 1,5

Confirm copy block:
Source: file#1 (/u01/xifenfei/system01.dbf), block 1 (entire 8192-byte block)
Target: file#1 (/u01/xifenfei/system01.dbf), block 5 (entire 8192-byte block)
Proceed? (Y/YES to confirm): y
Successfully copied block 1 from file#1 to block 5 in file#1 (8192 bytes).

OBET> set file 1 
filename set to: /u01/xifenfei/system01.dbf (file#1)

OBET> set count 128
count set to: 128

OBET> dump block 1 offset 0

File: /u01/xifenfei/system01.dbf
Block: 1                Offsets:     0 to   127
--------------------------------------------------------------------------------
00002000 01230000 01004000 00000000 00000104 28C60000 00000000 0004200B A2DB266A 
00002020 58494645 4E464549 AC020000 00720100 00200000 01000300 00000000 00000000 
00002040 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 
00002060 08024000 07000000 00000000 7DC92131 12345678 87654321 00000000 00000000 

<128 bytes read>

OBET> dump block 5 offset 0

File: /u01/xifenfei/system01.dbf
Block: 5                Offsets:     0 to   127
--------------------------------------------------------------------------------
0000A000 01230000 01004000 00000000 00000104 28C60000 00000000 0004200B A2DB266A 
0000A020 58494645 4E464549 AC020000 00720100 00200000 01000300 00000000 00000000 
0000A040 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 
0000A060 08024000 07000000 00000000 7DC92131 12345678 87654321 00000000 00000000 

<128 bytes read>

copy chkscn功能演示

OBET> p kcvfh.kcvfhckp
File: H:\xifenfei\system01.dbf
Size: 8192 bytes
Block: 1
Offset: 484

struct kcvfhckp, 36 bytes                   @484
   struct kcvcpscn, 8 bytes                 @484
      ub4 kscnbas                          @484     0x1BDDBF09
      ub2 kscnwrp                          @488     0x163D
      ub2 kscnwrp2                         @490     0x0000
   ub4 kcvcptim                            @492     0x488361FC
   ub2 kcvcpthr                            @496     0x0001
   union u, 12 bytes                       @500
      struct kcvcprba, 12 bytes            @500
         ub4 kcrbaseq                     @500     0x0006E3D3
         ub4 kcrbabno                     @504     0x0000B44B
         ub2 kcrbabof                     @508     0x0010
   ub1 kcvcpetb[8]                         @512-519 02 00 00 00 00 00 00 00


OBET> p kcvfh.kcvfhckp
File: H:\xifenfei\sysaux01.dbf
Size: 8192 bytes
Block: 1
Offset: 484

struct kcvfhckp, 36 bytes                   @484
   struct kcvcpscn, 8 bytes                 @484
      ub4 kscnbas                          @484     0x67452301
      ub2 kscnwrp                          @488     0x0000
      ub2 kscnwrp2                         @490     0x0000
   ub4 kcvcptim                            @492     0x00000000
   ub2 kcvcpthr                            @496     0x0000
   union u, 12 bytes                       @500
      struct kcvcprba, 12 bytes            @500
         ub4 kcrbaseq                     @500     0x0006E3D3
         ub4 kcrbabno                     @504     0x0000B44B
         ub2 kcrbabof                     @508     0x0010
   ub1 kcvcpetb[8]                         @512-519 02 00 00 00 00 00 00 00

<kcvfh.kcvfhckp structure printed successfully>



OBET> copy chkscn file 1 to file 2

Confirm Modify chkscn:
Source: file#1 (H:\xifenfei\system01.dbf)
Target: file#2 (H:\xifenfei\sysaux01.dbf)
Proceed? (Y/YES to confirm): y
Successfully copied checkpoint SCN information from file#1 to file#2.

OBET> p kcvfh.kcvfhckp
File: H:\xifenfei\sysaux01.dbf
Size: 8192 bytes
Block: 1
Offset: 484

struct kcvfhckp, 36 bytes                   @484
   struct kcvcpscn, 8 bytes                 @484
      ub4 kscnbas                          @484     0x1BDDBF09
      ub2 kscnwrp                          @488     0x163D
      ub2 kscnwrp2                         @490     0x0000
   ub4 kcvcptim                            @492     0x488361FC
   ub2 kcvcpthr                            @496     0x0001
   union u, 12 bytes                       @500
      struct kcvcprba, 12 bytes            @500
         ub4 kcrbaseq                     @500     0x0006E3D3
         ub4 kcrbabno                     @504     0x0000B44B
         ub2 kcrbabof                     @508     0x0010
   ub1 kcvcpetb[8]                         @512-519 02 00 00 00 00 00 00 00

<kcvfh.kcvfhckp structure printed successfully>

copy resetlogscn功能演示

OBET> p kcvfh.kcvfhrlc
File: H:\xifenfei\system01.dbf
Size: 8192 bytes
Block: 1
Offset: 112

ub4 kcvfhrlc                             @112     0x3215EC5C

<kcvfh.kcvfhrlc structure printed successfully>

OBET> p kcvfh.kcvfhrls
File: H:\xifenfei\system01.dbf
Size: 8192 bytes
Block: 1
Offset: 116

struct kcvfhrls, 8 bytes                    @116
   ub4 kscnbas                             @116     0x000E74FF
   ub2 kscnwrp                             @120     0x0000
   ub2 kscnwrp2                            @122     0x0000

<kcvfh.kcvfhrls structure printed successfully>


OBET> p kcvfh.kcvfhrlc
File: H:\xifenfei\sysaux01.dbf
Size: 8192 bytes
Block: 1
Offset: 112

ub4 kcvfhrlc                             @112     0x67452301

<kcvfh.kcvfhrlc structure printed successfully>

OBET> p kcvfh.kcvfhrls
File: H:\xifenfei\sysaux01.dbf
Size: 8192 bytes
Block: 1
Offset: 116

struct kcvfhrls, 8 bytes                    @116
   ub4 kscnbas                             @116     0x43658709
   ub2 kscnwrp                             @120     0x0021
   ub2 kscnwrp2                            @122     0x0000

<kcvfh.kcvfhrls structure printed successfully>

OBET> copy resetlogscn file 1 to file 2

Confirm Modify resetlogscn:
Source: file#1 (H:\xifenfei\system01.dbf)
Target: file#2 (H:\xifenfei\sysaux01.dbf)
Proceed? (Y/YES to confirm): y
Successfully copied resetlog SCN information from file#1 to file#2.

OBET> p kcvfh.kcvfhrlc
File: H:\xifenfei\sysaux01.dbf
Size: 8192 bytes
Block: 1
Offset: 112

ub4 kcvfhrlc                             @112     0x3215EC5C

<kcvfh.kcvfhrlc structure printed successfully>

OBET> p kcvfh.kcvfhrls
File: H:\xifenfei\sysaux01.dbf
Size: 8192 bytes
Block: 1
Offset: 116

struct kcvfhrls, 8 bytes                    @116
   ub4 kscnbas                             @116     0x000E74FF
   ub2 kscnwrp                             @120     0x0000
   ub2 kscnwrp2                            @122     0x0000

<kcvfh.kcvfhrls structure printed successfully>

corrupt [block x]标记坏块功能

C:\Users\XFF>dbv file=h:/xifenfei/users01.dbf

DBVERIFY: Release 11.2.0.4.0 - Production on 星期三 11月 12 21:40:55 2025

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

DBVERIFY - 开始验证: FILE = H:\XIFENFEI\USERS01.DBF


DBVERIFY - 验证完成

检查的页总数: 26656
处理的页总数 (数据): 23569
失败的页总数 (数据): 0
处理的页总数 (索引): 309
失败的页总数 (索引): 0
处理的页总数 (其他): 720
处理的总页数 (段)  : 0
失败的总页数 (段)  : 0
空的页总数: 2058
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            : 2255414715 (18.2255414715)


OBET> corrupt block 10

Confirm modification:
File: h:/xifenfei/users01.dbf
Block: 10
Offset: 14 (file offset: 0x0001400E)
Original value: 01
New value:      FF
Are you sure to set this block corrupted? (Y/YES to proceed): y
Verification successful: Block 10 marked as corrupted (offset 14 set to 0xFF).
Modification successful.

C:\Users\XFF>dbv file=h:/xifenfei/users01.dbf

DBVERIFY: Release 11.2.0.4.0 - Production on 星期三 11月 12 21:41:22 2025

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

DBVERIFY - 开始验证: FILE = H:\XIFENFEI\USERS01.DBF
页 10 流入 - 很可能是介质损坏
Corrupt block relative dba: 0x0100000a (file 4, block 10)
Fractured block found during dbv:
Data in bad block:
 type: 30 format: 2 rdba: 0x0100000a
 last change scn: 0x0000.00003e78 seq: 0xff flg: 0x04
 spare1: 0x0 spare2: 0x0 spare3: 0x0
 consistency value in tail: 0x3e781e01
 check value in block header: 0x1a6
 computed block checksum: 0xfe



DBVERIFY - 验证完成

检查的页总数: 26656
处理的页总数 (数据): 23569
失败的页总数 (数据): 0
处理的页总数 (索引): 309
失败的页总数 (索引): 0
处理的页总数 (其他): 719
处理的总页数 (段)  : 0
失败的总页数 (段)  : 0
空的页总数: 2058
标记为损坏的总页数: 1
流入的页总数: 1
加密的总页数        : 0
最高块 SCN            : 2255414715 (18.2255414715)

repair [block x]修复坏块功能

C:\Users\XFF>dbv file=h:/xifenfei/undo01.dbf

DBVERIFY: Release 11.2.0.4.0 - Production on 星期日 11月 16 00:06:59 2025

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

DBVERIFY - 开始验证: FILE = H:\XIFENFEI\UNDO01.DBF
页 2 流入 - 很可能是介质损坏
Corrupt block relative dba: 0x02000002 (file 8, block 2)
Fractured block found during dbv:
Data in bad block:
 type: 29 format: 2 rdba: 0x02000002
 last change scn: 0x163d.1bddbcfa seq: 0xff flg: 0x04
 spare1: 0x0 spare2: 0x0 spare3: 0x0
 consistency value in tail: 0xbcfa1d02
 check value in block header: 0xec11
 computed block checksum: 0xfd



DBVERIFY - 验证完成

检查的页总数: 4880
处理的页总数 (数据): 0
失败的页总数 (数据): 0
处理的页总数 (索引): 0
失败的页总数 (索引): 0
处理的页总数 (其他): 4372
处理的总页数 (段)  : 11
失败的总页数 (段)  : 0
空的页总数: 507
标记为损坏的总页数: 1
流入的页总数: 1
加密的总页数        : 0
最高块 SCN            : 467517187 (5693.467517187)

OBET> repair

Repairing block 2 in file H:\xifenfei\undo01.dbf...

Repair analysis for block 2:
1. seq_kcbh check: 0xFF -> needs repair (0x01)
2. Tailchk check: 0x021DFABC -> needs repair (0x011DFABC)
3. Checksum check: 0x11EC -> OK

Confirm repair operations:
File: H:\xifenfei\undo01.dbf
Block: 2
Operations needed: fix offset14, fix tailchk
Confirm? (Y/YES to proceed): y

Verification after repair:
1. seq_kcbh: 0x01 OK
2. Tailchk: 0x011DFABC OK
3. Checksum: 0x11EC OK

Block 2 repair completed successfully.


C:\Users\XFF>dbv file=h:/xifenfei/undo01.dbf

DBVERIFY: Release 11.2.0.4.0 - Production on 星期日 11月 16 00:07:29 2025

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

DBVERIFY - 开始验证: FILE = H:\XIFENFEI\UNDO01.DBF


DBVERIFY - 验证完成

检查的页总数: 4880
处理的页总数 (数据): 0
失败的页总数 (数据): 0
处理的页总数 (索引): 0
失败的页总数 (索引): 0
处理的页总数 (其他): 4373
处理的总页数 (段)  : 11
失败的总页数 (段)  : 0
空的页总数: 507
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            : 467517187 (5693.467517187)

发表在小工具 | 标签为 obet, obet修复坏块, obet修改resetlogs, obet修改scn, obet标记坏块 | 评论关闭

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