大量的恢复经验和实战总结,逐步了完善obet(Oracle Block Edit Tool)功能和实现恢复的便利性.对于数据库恢复其中一个重要功能就是检测数据块的损坏情况(这个直接关系到恢复的实际效果),Oracle本身提供的dbv功能有一些不足,obet工具的dbv功能是对oracle本身的dbv功能的深度完善,弥补其本身的几个功能不足点:
1. Oracle dbv 需要安装oracle 软件,对于有些时候为了一个dbv检测需要安装Oracle 软件，成本和动作太大,obet工具直接单个文件即可运行
2. 如果数据文件头损坏,或者文件大小不对,或者block 0损坏,Oracle自带dbv均无法检测
3. Oracle dbv无法实现跨字节序检测(比如需要在win平台上检测aix系统的数据文件的坏块情况[比如硬件恢复场景需要])
4. Oracle dbv有些版本无法实现低版本dbv检测高版本数据库文件
5. Oracle dbv无法一条命令实现多个数据文件检测(需要人工写脚本来实现)

在使用obet的dbv功能之前需要准备listfile文件(内容格式:No Name)
listfile文件操作
1. 在可以mount的库中可以直接通过查询v$datafile(select file#,name from v$datafile),把结果保存到listfile.txt中
2. 通过obet的listfile功能直接获取

OBET> listfile
Usage: listfile <path|remove|edit>
  listfile <path>   - Scan directory and write to listfile.txt
  listfile remove   - Delete listfile.txt
  listfile edit [path] - Edit listfile.txt (notepad on Win, vi on Linux)

listfile 支持*通配符

OBET> listfile e:\oradata\orcl\sys*.dbf
Listed 2 files from 'e:\oradata\orcl' to listfile.txt (starting from #1).

OBET> open listfile.txt
Loaded 2 files from  datafile list 'listfile.txt'.

OBET> info

Loaded files (2 total):
----------------------------------------
Number  Path
----------------------------------------
     1  e:\oradata\orcl\SYSAUX01.DBF
     2  e:\oradata\orcl\SYSTEM01.DBF
----------------------------------------

listfile remove 直接删除掉当前目录下面的listfile.txt文件
listfile edit 直接调用notepad/vi 编辑模式打开当前目录下的listfile.txt文件(也可以指定具体文件名称)
3. 使用open命令加载listfile

OBET> open listfile.txt
Loaded 2 files from  datafile list 'listfile.txt'.

OBET> info

Loaded files (2 total):
----------------------------------------
Number  Path
----------------------------------------
     1  e:\oradata\orcl\SYSAUX01.DBF
     2  e:\oradata\orcl\SYSTEM01.DBF
----------------------------------------

dbv之前确认参数设置
在执行dbv之前需要先确认当前一些配置,和dbv相关的主要是blocksize(默认值为8192),endian(默认值为little),可以通过show命令查看(如果是检测linux/win环境下默认的oracle数据文件,理论上不用这修改这些值)

OBET> show

Current settings:
File: (not set)
Blocksize: 8192 bytes
Block: 1
Offset in block: 0 (file offset: 0x00002000)
Count: 32 bytes
Mode: browse
Endian: little (x86)
Loaded files: 2 (use 'info' to list)

可以根据情况通过set命令修改相关值,具体语法为:set

OBET> set
Usage: set <param> <value>
  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
  set endian big/little  - Set byte order (default: little, big for AIX files)

dbv 检测数据文件
具体语法为:dbv [file N [block M [blocks X]]]
dbv 检测open listfile中的所有数据文件的所有block
dbv file N 检测listfile中编号为N的数据文件的所有block
dbv file N block M 检测listfile中编号为N的数据文件的block M开始到文件结束
dbv file N block M block X 检测listfile中编号为N的数据文件的block M开始,检测X个block

OBET> dbv

===============================================
DBV (Data Block Verification)
Block Size: 8192 bytes
Endian:     little-endian (x86)
Target File: ALL files in listfile
===============================================

Verifying file #1: e:\oradata\orcl\SYSAUX01.DBF (139521 blocks) - Started: 2026-08-16 17:37:25
File #1: rfile=2 (0x00000002)  header_block_num=139520 (0x00022100)  filesize_status:OK
  Progress: 100000 / 139521 blocks checked...
  File #1 completed: no bad blocks found
Verifying file #2: e:\oradata\orcl\SYSTEM01.DBF (126721 blocks) - Started: 2026-08-16 17:37:26
File #2: rfile=1 (0x00000001)  header_block_num=126720 (0x0001EF00)  filesize_status:OK
  Progress: 100000 / 126721 blocks checked...
  File #2 completed: no bad blocks found

DBV completed at: 2026-08-16 17:37:26

===============================================
DBV Summary:
Total blocks checked: 266242
Total all zero blocks found: 0
Total all rdba error blocks found: 0
Total all tailchk error blocks found: 0
Total all soft corrupted blocks found: 0
Total all checksum error blocks found: 0
Total bad blocks found: 0
Execution time: 1.00 seconds
Throughput: 2080.02 MB/s
===============================================

Detailed report saved to: dbv_20260816173725.log
Files processed: 2

OBET> dbv file 1

===============================================
DBV (Data Block Verification)
Block Size: 8192 bytes
Endian:     little-endian (x86)
Target File: #1 (only)
===============================================

Verifying file #1: e:\oradata\orcl\SYSAUX01.DBF (139521 blocks) - Started: 2026-08-16 17:37:31
File #1: rfile=2 (0x00000002)  header_block_num=139520 (0x00022100)  filesize_status:OK
  Progress: 100000 / 139521 blocks checked...
  File #1 completed: no bad blocks found

DBV completed at: 2026-08-16 17:37:32

===============================================
DBV Summary:
Total blocks checked: 139521
Total all zero blocks found: 0
Total all rdba error blocks found: 0
Total all tailchk error blocks found: 0
Total all soft corrupted blocks found: 0
Total all checksum error blocks found: 0
Total bad blocks found: 0
Execution time: 1.00 seconds
Throughput: 1090.01 MB/s
===============================================

Detailed report saved to: dbv_file_1_20260816173731.log
Files processed: 1

OBET> dbv file 1 block 128

===============================================
DBV (Data Block Verification)
Block Size: 8192 bytes
Endian:     little-endian (x86)
Target File: #1, block 128 to end
===============================================

Verifying file #1: e:\oradata\orcl\SYSAUX01.DBF (block 128 to 139520, 139393 blocks) - Started: 2026-08-16 17:37:42
File #1: rfile=2 (0x00000002)  header_block_num=139520 (0x00022100)  filesize_status:OK
  Progress: 100128 / 139521 blocks checked...
  File #1 completed: no bad blocks found

DBV completed at: 2026-08-16 17:37:43

===============================================
DBV Summary:
Total blocks checked: 139393
Total all zero blocks found: 0
Total all rdba error blocks found: 0
Total all tailchk error blocks found: 0
Total all soft corrupted blocks found: 0
Total all checksum error blocks found: 0
Total bad blocks found: 0
Execution time: 1.00 seconds
Throughput: 1090.01 MB/s
===============================================

Detailed report saved to: dbv_file_1_block_128_20260816173742.log
Files processed: 1

OBET> dbv file 1 block 128 blocks 10

===============================================
DBV (Data Block Verification)
Block Size: 8192 bytes
Endian:     little-endian (x86)
Target File: #1, block 128 - 137 (10 blocks)
===============================================

Verifying file #1: e:\oradata\orcl\SYSAUX01.DBF (block 128 to 137, 10 blocks) - Started: 2026-08-16 17:37:47
File #1: rfile=2 (0x00000002)  header_block_num=139520 (0x00022100)  filesize_status:OK
  File #1 completed: no bad blocks found

DBV completed at: 2026-08-16 17:37:47

===============================================
DBV Summary:
Total blocks checked: 10
Total all zero blocks found: 0
Total all rdba error blocks found: 0
Total all tailchk error blocks found: 0
Total all soft corrupted blocks found: 0
Total all checksum error blocks found: 0
Total bad blocks found: 0
Execution time: 0.00 seconds
Throughput: 0.00 MB/s
===============================================

Detailed report saved to: dbv_file_1_block_128_20260816173747.log
Files processed: 1

检测的具体明细可以看obet所在的当前目录中的dbv*.log文件,里面有坏块类型:
rdba error:表示block#和该块所在位置不匹配
tailchk/checksum error:表示该block不满足Oracle的校验规则
soft corrupted:表示该block在Oracle数据库标记为坏块
zero block:表示该block中全部为0,一般是由于底层损坏,或者硬件恢复过程使用空块替代引起
filesize_status:NO表示文件实际大小和文件头记录大小不匹配
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