分类目录归档:数据库

在生产环境错误执行dd命令破坏asm磁盘故障恢复

由于ssh登录错误,客户对生产环境进行了误操作把系统的一块磁盘dd到另外两个磁盘上,由于及时发现立马进行了终止操作,但是还是分别破坏了一点数据(一块盘破坏了2G多,另外一块盘破坏了1G多)
dd


通过分析udev的绑定关系确认被破坏的asm disk名称
udev

再通过asm alert日志确认破坏磁盘在asm disk中情况
asmdisk

通过上述信息基本上可以确认,asmdisk13被分别dd到了asmdisk11和asmdisk26中了部分11
26

基于这种情况,由于asm disk被破坏了1-2G多,直接修复然后正常mount磁盘组基本上没有希望,经过分析以及与客户沟通,确认他们改系统是4节点组成的集群,1/2节点上面跑2套库,3/4节点上跑2套库,数据整体放在data_dg磁盘组中,需要恢复的库是第二个顺序创建的1套库(4套库中只需恢复一套即可),由于破坏的数据本身不多,而且需要恢复的数据不是最初写入asm磁盘组,基于这样的情况,需要恢复的数据库机会比较大.

由于现在三个磁盘头信息一致(一个磁盘被dd到另外两个磁盘上),因此第一步先把损坏的两个磁盘头进行简单修复,为了便于amdu(找回ASM中数据文件)等之类数据可以识别到正确的磁盘头信息,然后进行后续的数据文件提取恢复.使用工具对数据文件进行了批量提取,提取数据完成之后,尝试recover和open库
open

虽然数据库正常打开了,不过很不幸,后台还是有一些坏块报错,通过dbv检查发现有文件有一部分坏块,类似dbv报错信息
1_1

通过分析该文件在磁盘组中各个磁盘的分布情况
map

确认该文件确实有部分block分布在被dd磁盘的破坏的范围内这个部分的数据丢失无法挽回,只能是定位到具体对象然后由业务想办法处理.相对以往的各种dd破坏的案例恢复而言,这个应该是效果比较好的一个,而且也是恢复比较容易的一个,没有使用到asm disk 基于asm au/oracle block 扫描的级别,而且system表空间没有任何损坏,数据库甚至直接open成功了,以往的一些dd案例列举:
asm磁盘dd破坏恢复
dd破坏asm磁盘头恢复
asm disk 磁盘部分被清空恢复

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obet实现对数据文件坏块检测功能

通过一段时间的测试和使用,obet修复了不少bug,关于obet的以往功能和特性的文章:
Oracle数据块编辑工具( Oracle Block Editor Tool)-obet
obet(Oracle Block Editor Tool)第二版发布
并且也在客户的生产环境上进行了实战:obet快速修改scn/resetlogs恢复数据库(缺少归档,ORA-00308).利用周末的时间又对obet的工具进行了功能增强,增加了dbv(数据块校验)功能.

Oracle dbv的不足
1. oracle dbv需要在安装oracle服务端的环境下才能执行
2. oracle dbv对于文件大小不正确(文件头记录block数和实际文件大小不匹配),文件头损坏等情况都可能导致dbv无法执行,类似下面的报错

C:\Users\XFF>dbv file=H:\BaiduNetdisk\kingdee\system01.dbf

DBVERIFY: Release 11.2.0.4.0 - Production on 星期日 1月 11 17:30:29 2026

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


DBV-00107: 未知标头格式 (0) (2054913149)

C:\Users\XFF>
C:\Users\XFF>dbv file=H:\BaiduNetdisk\kingdee\users01.dbf

DBVERIFY: Release 11.2.0.4.0 - Production on 星期日 1月 11 20:10:05 2026

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


DBV-00102: FILE (H:\BAIDUNETDISK\KINGDEE\USERS01.DBF) 在 end read 操作 (-1) 期间出现文件 I/O 错误

C:\Users\XFF>

3. oracle dbv一条命令执行检测一个数据文件,如果数据文件多,检查起来很繁琐
4. oracle dbv么有检查进度,对于io性能较慢,数据文件较大的情况,无法跟踪检查进度.

obet的dbv功能使用
1. 配置listfile.txt文件,格式为file# name

1 H:\BaiduNetdisk\kingdee\system01.dbf
5 H:\BaiduNetdisk\kingdee\EAS_D_EAS_STANDARD.ORA

2. 启动obet,执行open listfile.txt(如果不在obet目录提供完整路径)

OBET> open listfile.txt
Loaded 2 files from config file 'listfile.txt'.

OBET> info

Loaded files (2 total):
----------------------------------------
Number  Path
----------------------------------------
     1  H:\BaiduNetdisk\kingdee\system01.dbf
     5  H:\BaiduNetdisk\kingdee\EAS_D_EAS_STANDARD.ORA
----------------------------------------

3. 执行dbv命令(logfile 部分为可选),默认会记录日志在obet目录下面dbv_年月日时分秒.log的日志

OBET> dbv

===============================================
DBV (Data Block Verification)
Block Size: 8192 bytes
===============================================

Verifying file #1: H:\BaiduNetdisk\kingdee\system01.dbf (131841 blocks) - Started: 2026-01-11 18:03:58
file 1, block 0: checksum error (expected 0xC4DA, got 0xC478), bad block
file 1, block 1: checksum error (expected 0xF835, got 0xB835), bad block
  Progress: 10000 / 131841 blocks checked...
  Progress: 20000 / 131841 blocks checked...
……………….
  Progress: 120000 / 131841 blocks checked...
  Progress: 130000 / 131841 blocks checked...
  File #1 completed: 0 all zero, 0 soft corrupted, 0 tailchk error, 2 checksum error, 0 rdba error
Verifying file #5: H:\BaiduNetdisk\kingdee\EAS_D_EAS_STANDARD.ORA (4194303 blocks) - Started: 2026-01-11 18:04:08
  Progress: 10000 / 4194303 blocks checked...
  Progress: 20000 / 4194303 blocks checked...
……………………
  Progress: 260000 / 4194303 blocks checked...
  Progress: 270000 / 4194303 blocks checked...
file 5, block 277678: tailchk error (expected 0x0228BB21, got 0x0228AD21), bad block
file 5, block 277679: rdba error (expected 277679, got 277615), bad block
file 5, block 277680: rdba error (expected 277680, got 277616), bad block
file 5, block 277681: rdba error (expected 277681, got 277617), bad block
………………
file 5, block 277692: rdba error (expected 277692, got 277628), bad block
file 5, block 277693: rdba error (expected 277693, got 277629), bad block
file 5, block 277694: rdba error (expected 277694, got 277630), bad block
file 5, block 279406: tailchk error (expected 0x02281E22, got 0x00000700), bad block
file 5, block 279407: rdba error (expected 279407, got 448), bad block
file 5, block 279408: rdba error (expected 279408, got 0), bad block
………………
  Progress: 280000 / 4194303 blocks checked...
  Progress: 290000 / 4194303 blocks checked...
  Progress: 300000 / 4194303 blocks checked...
  Progress: 310000 / 4194303 blocks checked...
file 5, block 312932: tailchk error (expected 0x0106C0B8, got 0x010629B8), bad block
file 5, block 312933: rdba error (expected 312933, got 312869), bad block
file 5, block 312934: rdba error (expected 312934, got 312870), bad block
file 5, block 312935: rdba error (expected 312935, got 312871), bad block
file 5, block 312936: rdba error (expected 312936, got 312872), bad block
file 5, block 312937: rdba error (expected 312937, got 312873), bad block
file 5, block 312938: rdba error (expected 312938, got 312874), bad block
file 5, block 312939: rdba error (expected 312939, got 312875), bad block
………………
  Progress: 4180000 / 4194303 blocks checked...
  Progress: 4190000 / 4194303 blocks checked...
  File #5 completed: 1 all zero, 0 soft corrupted, 13 tailchk error, 1 checksum error, 255 rdba error

DBV completed at: 2026-01-11 18:09:30

===============================================
DBV Summary:
Total blocks checked: 4325872
Total all zero blocks found: 1
Total all rdba error blocks found: 255
Total all tailchk error blocks found: 13
Total all soft corrupted blocks found: 0
Total all checksum error blocks found: 3
Total bad blocks found: 272
===============================================

Detailed report saved to: dbv_20260111180358.log

OBET>

检测效果截图
obet-dbv


obet工具下载地址:obet下载
obet工具使用说明:obet使用说明

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obet快速修改scn/resetlogs恢复数据库(缺少归档,ORA-00308)

最初是由于业务系统报ORA-01578导致
blk


然后相关人员上来进行了一系列操作,包括但不限于offline文件,create datafile 44,recover datafile,还尝试做resetlogs,使用备份控制文件还原等等.我接手该故障的时候状态
resetlog
44号文件状态是12月1日的,而且resetlogs信息也不对.通过和客户沟通,确认是他们在没有备份44号文件的前提下直接执行了类似alter database create datafile 44的命令,但是在应用了写归档之后,发现提示有归档不存在

ALTER DATABASE RECOVER    CONTINUE DEFAULT
Media Recovery Log /data/app/oracle/archive/orcl/1_181285_1103629544.dbf
ORA-279 signalled during: ALTER DATABASE RECOVER    CONTINUE DEFAULT  ...
ALTER DATABASE RECOVER    CONTINUE DEFAULT
Media Recovery Log /data/app/oracle/archive/orcl/1_181286_1103629544.dbf
Tue Jan 06 12:48:12 2026
Errors with log /data/app/oracle/archive/orcl/1_181286_1103629544.dbf
Errors in file /data/app/oracle/diag/rdbms/orcl8/orcl/trace/orcl_pr00_8338.trc:
ORA-00308: cannot open archived log '/data/app/oracle/archive/orcl/1_181286_1103629544.dbf'
ORA-27037: unable to obtain file status
Linux-x86_64 Error: 2: No such file or directory
Additional information: 3

分析现存归档,确实发现12月1日之后丢失了部分归档日志(归档不连续)
arch


基于这种情况(故障数据文件直接被覆盖,归档又出现了多天的连续断档,而且没有有效备份),只能先打开数据库,然后根据情况导出数据,然后导入到新库中.这里我直接使用obet来修改resetlogs和checkpoint 信息,实现数据库快速打开

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
  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
  backup [file n] [block m] - Backup data block (optional file and block parameters)
  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
  spool <file>          - Start logging to file (spool off to stop)
  help                  - Show this help message
  quit/exit             - Exit OBET

OBET> open 1.txt                 
Loaded 2 files from config file '1.txt'.

OBET> info

Loaded files (2 total):
----------------------------------------
Number  Path
----------------------------------------
     1  /data/app/oracle/oradata/orcl/system01.dbf
    44  /data/app/oracle/oradata/orcl/xff26.dbf
----------------------------------------

OBET> set file 44
filename set to: /data/app/oracle/oradata/orcl/xff26.dbf (file#44)

OBET> d

File: /data/app/oracle/oradata/orcl/xff26.dbf
Block: 1                Offsets:     0 to    31
--------------------------------------------------------------------------------
0xifenfei000 0BA20000 0100000B 00000000 00000104 B05F0000 00000000 0004200B 65583D61 

<32 bytes read>


OBET> backup file 44 block 1
Created backup directory: backup_blk
Successfully backed up block 1 from file#44 to /tmp/backup_blk/xff26.dbf_1.20260106182405

OBET> copy resetlogscn file 1 to file 44
Error: Edit mode not enabled. Use 'set mode edit' first.

OBET> set mode edit     
mode set to: edit

OBET> copy resetlogscn file 1 to file 44

Confirm Modify resetlogscn:
Source: file#1 (/data/app/oracle/oradata/orcl/system01.dbf)
Target: file#44 (/data/app/oracle/oradata/orcl/xff26.dbf)
Proceed? (Y/YES to confirm): y
Successfully copied resetlog SCN information from file#1 to file#44.

OBET> copy chkscn file 1 to file 44

Confirm Modify chkscn:
Source: file#1 (/data/app/oracle/oradata/orcl/system01.dbf)
Target: file#44 (/data/app/oracle/oradata/orcl/xff26.dbf)
Proceed? (Y/YES to confirm): y
Successfully copied checkpoint SCN information from file#1 to file#44.

OBET> tailchk
Check tailchk for File /data/app/oracle/oradata/orcl/xff26.dbf, Block 1:
current = 0x010B0000, required = 0x010B0000

OBET> sum
Check value for File /data/app/oracle/oradata/orcl/xff26.dbf, Block 1:
current = 0xB05F, required = 0x6DA3

OBET> sum apply

Confirm applying checksum:
File: /data/app/oracle/oradata/orcl/xff26.dbf
Block: 1
Offset in block: 16 (file offset: 0x0xifenfei010)
Original value: 0xB05F
New value:      0x6DA3
Confirm? (Y/YES to proceed): y
Verification successful: Stored checksum matches calculated value (0x6DA3).
Checksum applied successfully.

然后重建ctl正常打开数据库

[oracle@xifenfei check_db]$ sqlplus / as sysdba

SQL*Plus: Release 11.2.0.4.0 Production on Tue Jan 6 18:29:22 2026

Copyright (c) 1982, 2013, Oracle.  All rights reserved.

Connected to an idle instance.

SQL> startup mount pfile='/tmp/pfile';
ORACLE instance started.

Total System Global Area 6.8413E+10 bytes
Fixed Size		    2270360 bytes
Variable Size		 3.3554E+10 bytes
Database Buffers	 3.4762E+10 bytes
Redo Buffers		   93585408 bytes
Database mounted.
SQL> alter database open;
alter database open
*
ERROR at line 1:
ORA-01190: control file or data file 1 is from before the last RESETLOGS
ORA-01110: data file 1: '/data/app/oracle/oradata/orcl/system01.dbf'


SQL> shutdown immediate;
ORA-01109: database not open


Database dismounted.
ORACLE instance shut down.
SQL> 
SQL> 
SQL> startup nomount pfile='/tmp/pfile
';
ORACLE instance started.

Total System Global Area 6.8413E+10 bytes
Fixed Size		    2270360 bytes
Variable Size		 3.3554E+10 bytes
Database Buffers	 3.4762E+10 bytes
Redo Buffers		   93585408 bytes
SQL> @ctl.sql

Control file created.

SQL> SQL> recover database;
ORA-00283: recovery session canceled due to errors
ORA-00264: no recovery required


SQL> alter database open;

Database altered.

后续根据情况选择导出表,对于导出报错的表再进行二次处理.
obet工具下载地址:obet下载
obet工具使用说明:obet使用说明

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