mysql drop database 恢复思路

Posted on 2025 年 11 月 30 日 by 惜分飞

今天有一个客户在在虚拟机环境中使用drop database删除一个业务mysql的库,删除之后,第一时间关闭了该虚拟机系统.接到该case请求之后,让客户提供了虚拟机文件(vmdk),通过工具分析,mysql数据库是放在/分区下面的/data里面(lvm结构，xfs文件系统),但是已经看不到他们删除的数据库(mysql一个库对应一个目录)

对于这种情况,我们第一步尝试文件系统层面反删除恢复(对数据库所在分区进行文件系统层面扫描,尝试恢复被删除的mysql表文件),运气不错,找到了一些被删除库的ibd文件

对于这些文件,选择出来客户需要的表,采用discard+import方式进行恢复,类似命令

alter table tablename discard tablespace;
alter table tablename import tablespace;

对于有些部分block损坏的ibd文件,直接这样操作可能会报Data structure corruption错误,这样的情况,可以通过工具解析ibd文件进行恢复

对于有些表,可能在文件系统层面反删除无法恢复,我们通过对磁盘进行mysql的数据块层面扫描(识别在磁盘上没有覆盖的mysql的block),按照pageid的方式进行重组成一个个page文件

然后基于这些page进行恢复需要的表数据

基本上通过上述的方法实现最大限度mysql删除数据的恢复(比如drop database，drop table，truncate table)
如果MySQL数据库恢复问题,需要专业恢复技术支持，请联系我们提供专业MySql数据库恢复服务:
电话/微信:17813235971 Q Q:107644445 E-Mail:dba@xifenfei.com

PRVG-11975 : The I/O scheduler parameter of device “/dev/sdm” did not match the expected value on nodes

Posted on 2025 年 11 月 24 日 by 惜分飞

联系：手机/微信(+86 17813235971) QQ(107644445)

标题：PRVG-11975 : The I/O scheduler parameter of device “/dev/sdm” did not match the expected value on nodes

今天在oracle linux 7.9的系统中装Oracle 19.29集群采用gridSetup applyRU 的方式安装

su – grid
cd $ORACLE_HOME
./gridSetup.sh -applyRU /soft/38298204/

在检测的步骤I/O scheduler warning

具体内容类似:

I/O scheduler - This task checks the I/O scheduler parameter configured Error: 
PRVG-11975:The I/O scheduler parameter of device "/dev/sdm" did not match the expected value on nodes "hisdb2,hisdb2". 
[Expected scheduler = "none" ; Found scheduler = "mq-deadline"] ? Cause:?The I/O scheduler parameter of the indicated 
device was not  the expected value on the indicated nodes. ? Action:?Change the I/O scheduler parameter using 
'echo deadline > /sys/block/<device>/queue/scheduler' command of the indicated device to ensure it is the expected value.

大概的意思是磁盘的I/O scheduler parameter被检查出来是mq-deadline,实际要求为:deadline,并建议使用echo deadline > /sys/block//queue/scheduler命令来修改,检查存储磁盘的实际值

[grid@hisdb1 grid]$ cat /sys/block/sdm/queue/scheduler
[mq-deadline] kyber bfq none

确实I/O scheduler为mq-deadline,查询了相关描述:
mq-deadline 是 deadline 调度器的多队列升级版，核心设计目标一致（按 “截止时间” 调度以保证 I/O 延迟），但适配的硬件场景、性能表现差异显著 —— 简单说：deadline 是为传统单队列设备（如 HDD）设计的老版本，mq-deadline 是为现代多队列设备（如 SSD/NVMe）优化的新版本。

客户这边刚好是华为的ssd存储,使用mq-deadline是非常合理的,如果调整为deadline反而不太合理了.初步感觉这个问题应该是Oracle 本身检测不合理导致,进一步查询MOS,Oracle自己也承认了该问题:

对于ssd环境,可以忽略该警告,继续安装

obet(Oracle Block Editor Tool)第二版发布

Posted on 2025 年 11 月 16 日 by 惜分飞

联系：手机/微信(+86 17813235971) QQ(107644445)

标题：obet(Oracle Block Editor Tool)第二版发布

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（下载地址:下载obet），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)

Oracle数据块编辑工具( Oracle Block Editor Tool)-obet

Posted on 2025 年 11 月 08 日 by 惜分飞

联系：手机/微信(+86 17813235971) QQ(107644445)

标题：Oracle数据块编辑工具( Oracle Block Editor Tool)-obet

由于oracle后续版本对于bbed的支持不是太友好(从10g之后无法直接编译使用,win版本偏移量错误等),基于这些情况,结合当前ai的便利,自己动手写了一个基础版的obet(Oracle Block Editor Tool),用来实现在某些情况下Oracle 数据块的编辑工作.目前(2025年11月7日)发布第一版主要功能有:
1. 通过16进制查看数据文件任何偏移量位置的数据(d/dump)
2. 通过16进制编辑数据文件任何偏移量位置的数据(m/modify)
3. 对oracle 数据块的tailchk自动修复(tailchk apply)
4. 对oracle 数据块的checksum自动修复(sum apply)
5. 数据文件之间部分数据拷贝功能(coopy)

启动软件界面

[root@iZbp11c0qyuuo1gr7j98upZ tmp]# ./obet
=============================================
Welcome to Oracle Block Editor Tool (OBET)
=============================================

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

[Software Function Description]
- View and edit data block in hexadecimal format
- Automatically repair tailchk and checksum
- Copy data between different data files
- Mark data block as corrupted block

[Developer Information]
- Name: XiFenFei
- Phone: +86-17813235971
- Email: dba@xifenfei
- Q Q: 107644445
- WeChat: 17813235971
- Website: https://www.xifenfei.com

[Version Details]
- Software Version: v2025.11.001
- Build Date: 2025.11.07

=============================================
Type 'help' for command list | 'exit' to quit
=============================================

==================================================
Software License Status: Authorized
==================================================

使用说明

OBET> help
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
  copy <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)
  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
  help                  - Show this help message
  quit/exit             - Exit OBET

加载数据文件

--使用open打开数据文件列表(格式: 编号  路径)
OBET> open /tmp/3.txt
Loaded 4 files from config file '/tmp/3.txt'.

OBET> info

Loaded files (4 total):
----------------------------------------
Number  Path
----------------------------------------
     1  /u01/xifenfei/system01.dbf
     2  /u01/xifenfei/sysaux01.dbf
     3  /u01/xifenfei/undotbs01.dbf
     4  /u01/xifenfei/users01.dbf
----------------------------------------

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

--或者直接使用 set filename
OBET> set filename /tmp/system01.dbf
filename set to: /tmp/system01.dbf

进入数据文件特定位置

OBET> set file 2
filename set to: /u01/xifenfei/sysaux01.dbf (file#2)

OBET> set block 5
block set to: 5

OBET> set offset 128
offset set to: 128

16进制方式查看数据

OBET> d

File: /u01/xifenfei/system01.dbf
Block: 1                Offsets:     0 to    31
--------------------------------------------------------------------------------
00002000 0BA20000 01004000 00000000 00000104 224D0000 00000000 0004200B A2DB266A 

<32 bytes read>

OBET> dump block 521 offset 128

File: /u01/xifenfei/system01.dbf
Block: 521                Offsets:   128 to   159
--------------------------------------------------------------------------------
00412080 5E068D05 C6040000 00000000 00000000 00000000 00000000 00000000 00000000 

<32 bytes read>

OBET> set count 128
count set to: 128

OBET> d

File: /u01/xifenfei/system01.dbf
Block: 1                Offsets:     0 to   127
--------------------------------------------------------------------------------
00002000 0BA20000 01004000 00000000 00000104 224D0000 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 64676345 06200E00 00000000 00000000 

<128 bytes read>

16进制方式修改数据块内容(一般修改数据块内容之后建议校验tailchk和sum)

OBET> d

File: /u01/xifenfei/system01.dbf
Block: 1                Offsets:     0 to   127
--------------------------------------------------------------------------------
00002000 0BA20000 01004000 00000000 00000104 224D0000 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 64676345 06200E00 00000000 00000000 

<128 bytes read>

OBET> m 0123

Confirm modification:
File: /u01/xifenfei/system01.dbf
Block: 1
Offset: 0 (file offset: 0x00002000)
Original value: 0B
New value:      0123
Confirm? (Y/YES to proceed): y
Verification successful: Data written correctly.
Modified 2 bytes at offset 0x00002000 successfully.

OBET> d

File: /u01/xifenfei/system01.dbf
Block: 1                Offsets:     0 to   127
--------------------------------------------------------------------------------
00002000 01230000 01004000 00000000 00000104 224D0000 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 64676345 06200E00 00000000 00000000 

<128 bytes read>

tail和checksum修改

OBET> tailchk
Check tailchk for File /u01/xifenfei/system01.dbf, Block 1:
current = 0x010B0000, required = 0x01010000

OBET> sum
Check value for File /u01/xifenfei/system01.dbf, Block 1:
current = 0x224D, required = 0x28CC

OBET> tailchk apply

Confirm applying tailchk:
File: /u01/xifenfei/system01.dbf
Block: 1
Offset in block: 8188 (file offset: 0x00003FFC)
Original value: 0x010B0000
New value:      0x01010000
Confirm? (Y/YES to proceed): y
Verification successful: Stored tailchk matches calculated value (0x01010000).
Tailchk applied successfully.

OBET> sum apply

Confirm applying checksum:
File: /u01/xifenfei/system01.dbf
Block: 1
Offset in block: 16 (file offset: 0x00002010)
Original value: 0x224D
New value:      0x28C6
Confirm? (Y/YES to proceed): y
Verification successful: Stored checksum matches calculated value (0x28C6).
Checksum applied successfully.

两个数据文件之前拷贝数据(一般copy数据之后建议校验tailchk和sum)
一般情况下文件之间的拷贝就是数据号不一样,比如修改checkpoint,resetlog信息等,这里支持不一样偏移量,不一样数据块的拷贝

OBET> copy 1,1,0,128 to 3,5,128

Confirm copy:
Source: file#1 (/u01/xifenfei/system01.dbf), block 1, offset 0, 128 bytes
Target: file#3 (/u01/xifenfei/undotbs01.dbf), block 5, offset 128
Proceed? (Y/YES to confirm): y
Copy successful: 128 bytes copied from file #1 to file #3.

OBET> set file 3
filename set to: /u01/xifenfei/undotbs01.dbf (file#3)

OBET> d block 5 offset 128

File: /u01/xifenfei/undotbs01.dbf
Block: 5                Offsets:   128 to   255
--------------------------------------------------------------------------------
0000A080 0BA20000 01004000 00000000 00000104 224D0000 00000000 0004200B A2DB266A 
0000A0A0 58494645 4E464549 AC020000 00720100 00200000 01000300 00000000 00000000 
0000A0C0 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 
0000A0E0 08024000 07000000 00000000 7DC92131 64676345 06200E00 00000000 00000000 

<128 bytes read>

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

OBET> dump block 1 offset 0

File: /u01/xifenfei/system01.dbf
Block: 1                Offsets:     0 to   127
--------------------------------------------------------------------------------
00002000 0BA20000 01004000 00000000 00000104 224D0000 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 64676345 06200E00 00000000 00000000 

<128 bytes read>

标记数据块为坏块功能


OBET> show 

Current settings:
File: /u01/xifenfei/system01.dbf
Blocksize: 8192 bytes
Block: 1
Offset in block: 0 (file offset: 0x00002000)
Count: 128 bytes
Mode: edit
Loaded files: 4 (use 'info' to list)

OBET> corrupt

Confirm modification:
File: /u01/xifenfei/system01.dbf
Block: 1
Offset: 14 (file offset: 0x0000200E)
Original value: 01
New value:      FF
Are you sure to set this block corrupted? (Y/YES to proceed): y
Verification successful: Block 1 marked as corrupted (offset 14 set to 0xFF).
Modification successful.

由于该工具直接编辑Oracle 底层数据块操作具有一定的破坏性和风险性,所以在没有授权的情况下无法对数据块进行修改(只能查看),具体授权操作

OBET> license

========================================
           Software Registration        
========================================

Your Hardware ID: XXXXXXXX  ----->提供给我

Please send your Hardware ID to XiFenFei to register.
Website: https://www.xifenfei.com 
Tel/WX: +86-17813235971 

Enter Registration Code: XXXXXX-XXXXXXXX <-----输入注册码进行授权
Registration successful!

Oracle坏块修复工具:Patch_blk

Posted on 2025 年 11 月 04 日 by 惜分飞

联系：手机/微信(+86 17813235971) QQ(107644445)

标题：Oracle坏块修复工具:Patch_blk

在win平台上开发了Oracle Recovery Tools小工具,可以实现坏块的快速恢复功能

具体参考相关文章:自研Oracle恢复小工具
由于之前工具使用c#开发不太方便实现跨平台(而且图形化在linux等操作系统上使用起来不方便),现在使用c语言写了小工具:Patch_blk(主要是seq_kcbh tailchk checksum类似坏块处理),模拟两个坏块

BBED> verify
DBVERIFY - Verification starting
FILE = /u01/app/oracle/oradata/xifenfei/system01.dbf
BLOCK = 521

Block 521 is corrupt
Corrupt block relative dba: 0x00400209 (file 0, block 521)
Fractured block found during verification
Data in bad block:
 type: 6 format: 2 rdba: 0x00400209
 last change scn: 0x0000.000001d7 seq: 0x1 flg: 0x06
 spare1: 0x0 spare2: 0x0 spare3: 0x0
 consistency value in tail: 0x01d706fe
 check value in block header: 0x5205
 computed block checksum: 0x0


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           : 2
Message 531 not found;  product=RDBMS; facility=BBED


BBED> verify block 522
DBVERIFY - Verification starting
FILE = /u01/app/oracle/oradata/xifenfei/system01.dbf
BLOCK = 522

Block 522 is corrupt
Corrupt block relative dba: 0x0040020a (file 0, block 522)
Fractured block found during verification
Data in bad block:
 type: 6 format: 2 rdba: 0x0040020a
 last change scn: 0x0000.000001d7 seq: 0xff flg: 0x06
 spare1: 0x0 spare2: 0x0 spare3: 0x0
 consistency value in tail: 0x01d70601
 check value in block header: 0x1e16
 computed block checksum: 0x0


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           : 2
Message 531 not found;  product=RDBMS; facility=BBED

配置坏块修复列表文件

[root@iZbp11c0qyuuo1gr7j98upZ tmp]# cat 1.txt
/u01/app/oracle/oradata/xifenfei/system01.dbf  521 8192 N
/u01/app/oracle/oradata/xifenfei/system01.dbf  522 8192 Y 

--列表文件说明
数据文件路径 文件号 数据块大小 是否人工干预(N表示不需要,Y表示需要)

执行修复操作

[root@iZbp11c0qyuuo1gr7j98upZ tmp]# ./Patch_blk 1.txt


===== Processing line 1 =====
=====================================================
Processing: File=/u01/app/oracle/oradata/xifenfei/system01.dbf, Block=521, Size=8192, Mode=N
=====================================================

=== Step 1: Check seq_kcbh ===
  Current value: 0x01
  [OK] seq_kcbh is normal

=== Step 2: Check tailchk ===
  Current (reversed): 0x01D706FE
  Expected (reversed): 0x01D70601
  [Auto-repair] tailchk mismatch, will fix
  [Backup] Block saved to: ./20251104_230616/system01.dbf_block521
  [Success] tailchk fixed
  [Verify] New tailchk (reversed): 0x01D70601

=== Step 3: Check checksum  ===
  Current checksum: 0x0552
  Computed checksum: 0xFA52
  [Auto-repair] Checksum mismatch, will fix
  [Success] Checksum fixed
  [Verify] New checksum: 0xFA52

=== Step 4: Final Verification ===
  seq_kcbh: 0x01 (not 0xFF: PASS)
  tailchk: 0x01D70601 (expected 0x01D70601: PASS)
  Checksum: 0xFA52 (expected 0xFA52: PASS)

[Result] Block repair completed successfully


===== Processing line 2 =====
=====================================================
Processing: File=/u01/app/oracle/oradata/xifenfei/system01.dbf, Block=522, Size=8192, Mode=Y
=====================================================

=== Step 1: Check seq_kcbh ===
  Current value: 0xFF
  [WARNING] Block is marked as BAD. Repair? (yes/no): y
  [Backup] Block saved to: ./20251104/system01.dbf_block522
  [Success] seq_kcbh updated to 0x01

=== Step 2: Check tailchk ===
  Current (reversed): 0x01D70601
  Expected (reversed): 0x01D70601
  [OK] tailchk is normal

=== Step 3: Check checksum ===
  Current checksum: 0x161E
  Computed checksum: 0xE81E
  [WARNING] Checksum mismatch. Repair? (yes/no): y
  [Success] Checksum fixed
  [Verify] New checksum: 0xE81E

=== Step 4: Final Verification ===
  seq_kcbh: 0x01 (not 0xFF: PASS)
  tailchk: 0x01D70601 (expected 0x01D70601: PASS)
  Checksum: 0xE81E (expected 0xE81E: PASS)

[Result] Block repair completed successfully


=====================================
Processing complete. Total: 2
  Modify Success: 2
  Modify None: 0
  Skipped/Failed: 0
  Blocks Backed Up: 2
=====================================

在修复坏块之前会对相关block进行备份

[root@iZbp11c0qyuuo1gr7j98upZ 20251104]# ls -ltra
total 24
-rw-r--r--   1 root root 8192 Nov  4 22:42 system01.dbf_block521
-rw-r--r--   1 root root 8192 Nov  4 22:42 system01.dbf_block522
drwxr-xr-x   2 root root 4096 Nov  4 22:42 .
drwxrwxrwt. 14 root root 4096 Nov  4 23:39 ..
[root@iZbp11c0qyuuo1gr7j98upZ 20251104]#

Patch_blk修复坏块之后,检查坏块正常

BBED> verify
DBVERIFY - Verification starting
FILE = /u01/app/oracle/oradata/xifenfei/system01.dbf
BLOCK = 521


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> verify block 522
DBVERIFY - Verification starting
FILE = /u01/app/oracle/oradata/xifenfei/system01.dbf
BLOCK = 522


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

对于不太熟悉bbed的客户,可以通过这个工具快速实现常见坏块类型恢复