一、介绍
DBV(DBVERIFY)是Oracle提供的一个命令行工具，它可以对数据文件物理和逻辑两种一致性检查。但是这个工具不会检查索引记录和数据记录的匹配关系，这种检查必须使用analyze validate structure命令。
这个工具有如下特点：
- 以只读的方式打开数据文件，在检查过程中不会修改数据文件的内容。
- 可以在线检查数据文件，而不需要关闭数据库。
- DBV只会检查数据块的正确性，但不会关系数据块是否属于哪个对象。
dbv help=y
| 参数 |
含义 |
缺省值 |
| FILE |
要检查的数据文件名 |
没有缺省值 |
| START |
检查起始数据块号 |
数据文件的第一个数据块 |
| END |
检查的最后一个数据块号 |
数据文件的最后一个数据块 |
| BLOCKSIZE |
数据块大小，这个值要和数据库的DB_BLOCK_SIZE参数值一致 |
缺省值8192 |
| LOGFILE |
检查结果日志文件 |
没有缺省值 |
| FEEDBAK |
显示进度 |
0 |
| PARFILE |
参数文件名 |
没有缺省值 |
| USERID |
用户名、密码 |
没有缺省值 |
| SEGMENT_ID |
段ID，参数格式<tsn.segfile.segblock> |
没有缺省值 |
二、测试实验（db version:19.3.0.0，ASM）
1、检查ASM实例数据文件
[grid@p19c01 ~]$ dbv file=+DATA/ORCL/DATAFILE/SYSAUX.258.1067243075
DBVERIFY: Release 19.0.0.0.0 - Production on Thu Mar 18 07:15:40 2021
Copyright (c) 1982, 2019, Oracle and/or its affiliates. All rights reserved.
DBVERIFY - Verification starting : FILE = +DATA/ORCL/DATAFILE/SYSAUX.258.1067243075
DBVERIFY - Verification complete
Total Pages Examined : 69120
Total Pages Processed (Data) : 5437
Total Pages Failing (Data) : 0
Total Pages Processed (Index): 2684
Total Pages Failing (Index): 0
Total Pages Processed (Lob) : 25350
2、指定BLOCKSIZE检测数据文件，blocksize=8192kb
--获取数据库db_block_size
SQL> show parameter db_block_size
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
db_block_size integer 8192
--获取数据文件号
SQL> select file#,name from v$datafile;
FILE# NAME
---------- --------------------------------------------------------------------------------
1 +DATA/ORCL/DATAFILE/system.274.1067312029
3 +DATA/ORCL/DATAFILE/sysaux.275.1067312063
4 +DATA/ORCL/DATAFILE/undotbs1.276.1067312079
5 +DATA/ORCL/86B637B62FE07A65E053F706E80A27CA/DATAFILE/system.282.1067312545
6 +DATA/ORCL/86B637B62FE07A65E053F706E80A27CA/DATAFILE/sysaux.283.1067312545
7 +DATA/ORCL/DATAFILE/users.277.1067312079
8 +DATA/ORCL/86B637B62FE07A65E053F706E80A27CA/DATAFILE/undotbs1.284.1067312545
9 +DATA/ORCL/DATAFILE/undotbs2.286.1067312997
8 rows selected.
--获取数据文件1的END
SQL> select bytes/8192 from v$datafile where file#=1;
BYTES/8192
----------
113920
--检查数据文件是否有坏块
[oracle@p19c01 ~]$ dbv file=+DATA/ORCL/DATAFILE/system.274.1067312029 blocksize=8192 end=113920
DBVERIFY: Release 19.0.0.0.0 - Production on Thu Mar 18 07:28:51 2021
Copyright (c) 1982, 2019, Oracle and/or its affiliates. All rights reserved.
DBVERIFY - Verification starting : FILE = +DATA/ORCL/DATAFILE/system.274.1067312029
DBVERIFY - Verification complete
Total Pages Examined : 113920
Total Pages Processed (Data) : 79434
Total Pages Failing (Data) : 0
Total Pages Processed (Index): 12737
Total Pages Failing (Index): 0
Total Pages Processed (Other): 5111
Total Pages Processed (Seg) : 1
Total Pages Failing (Seg) : 0
Total Pages Empty : 16638
Total Pages Marked Corrupt : 0
Total Pages Influx : 0
Total Pages Encrypted : 0
Highest block SCN : 2369647 (0.2369647)
3、检查控制文件，blocksize=16384kb
--检测控制文件是否坏块
--不指定bolcksize会报错
[oracle@p19c01 ~]$ dbv file=+DATA/ORCL/CONTROLFILE/current.278.1067312147
DBVERIFY: Release 19.0.0.0.0 - Production on Thu Mar 18 08:23:06 2021
Copyright (c) 1982, 2019, Oracle and/or its affiliates. All rights reserved.
DBVERIFY - Verification starting : FILE = +DATA/ORCL/CONTROLFILE/current.278.1067312147
DBV-00111: OCI failure (4409) (ORA-19501: read error on file "+DATA/ORCL/CONTROLFILE/current.278.1067312147", block number 1 (block size=8192)
ORA-17507: I/O request size is not a multiple of logical block size.
ORA-06512: at "SYS.DBMS_DBVERIFY", line 24
ORA-06512: at line 1
)
--查看控制文件的blocksize为16K
[grid@p19c01 ~]$ dbfsize Current.261.1067243211
Database file: Current.261.1067243211
Database file type: file system
Database file size: 1202 16384 byte blocks
--指定blocksize为16K
[oracle@p19c01 ~]$ dbv file=+DATA/ORCL/CONTROLFILE/current.278.1067312147 blocksize=16384
DBVERIFY: Release 19.0.0.0.0 - Production on Thu Mar 18 08:24:03 2021
Copyright (c) 1982, 2019, Oracle and/or its affiliates. All rights reserved.
DBVERIFY - Verification starting : FILE = +DATA/ORCL/CONTROLFILE/current.278.1067312147
DBVERIFY - Verification complete
Total Pages Examined : 1202
Total Pages Processed (Data) : 0
Total Pages Failing (Data) : 0
Total Pages Processed (Index): 0
Total Pages Failing (Index): 0
Total Pages Processed (Other): 85
Total Pages Processed (Seg) : 0
Total Pages Failing (Seg) : 0
Total Pages Empty : 1117
Total Pages Marked Corrupt : 0
Total Pages Influx : 0
Total Pages Encrypted : 0
Highest block SCN : 1382 (0.1382)
4、检查单独的Segment
--查看对象的tsn,segfile,segblock属性：
select t.ts#,s.header_file,s.header_block
from v$tablespace t,dba_segments s
where s.segment_name='LUCIFER'
4 and t.name=s.tablespace_name;
TS# HEADER_FILE HEADER_BLOCK
---------- ----------- ------------
0 10 33600
--检查segment是否坏块
[oracle@p19c01 ~]$ dbv userid=lucifer/lucifer@pdb01 segment_id=0.10.33600
DBVERIFY: Release 19.0.0.0.0 - Production on Thu Mar 18 08:25:35 2021
Copyright (c) 1982, 2019, Oracle and/or its affiliates. All rights reserved.
DBVERIFY - Verification starting : SEGMENT_ID = 0.10.33600
DBV-00600: Fatal Error - [1] [1] [1] [1]
--
5、检查log文件（redo和arch）blocksize=512kb
[oracle@p19c01 ~]$ dbv file=+DATA/ORCL/ONLINELOG/group_1.280.1067312151
DBVERIFY: Release 19.0.0.0.0 - Production on Thu Mar 18 08:30:58 2021
Copyright (c) 1982, 2019, Oracle and/or its affiliates. All rights reserved.
DBVERIFY - Verification starting : FILE = +DATA/ORCL/ONLINELOG/group_1.280.1067312151
Segmentation fault (core dumped)
--将asm中redolog文件复制一份出来
[grid@p19c01 ~]$ asmcmd -p
ASMCMD [+] > cp +DATA/ORCL/ONLINELOG/group_1.280.1067312151 /home/grid
copying +DATA/ORCL/ONLINELOG/group_1.280.1067312151 -> /home/grid/group_1.280.1067312151
ASMCMD [+] > exit
[grid@p19c01 ~]$ ls
Current.261.1067243211 group_1.280.1067312151
--检查redo日志文件
[grid@p19c01 ~]$ dbv file=group_1.280.1067312151
DBVERIFY: Release 19.0.0.0.0 - Production on Thu Mar 18 08:32:20 2021
Copyright (c) 1982, 2019, Oracle and/or its affiliates. All rights reserved.
DBV-00103: Specified BLOCKSIZE (8192) differs from actual (512)
--查看redo log的blocksize为512k
[grid@p19c01 ~]$ dbv file=group_1.280.1067312151
DBVERIFY: Release 19.0.0.0.0 - Production on Thu Mar 18 08:32:20 2021
Copyright (c) 1982, 2019, Oracle and/or its affiliates. All rights reserved.
DBV-00103: Specified BLOCKSIZE (8192) differs from actual (512)
[grid@p19c01 ~]$ dbfsize group_1.280.1067312151
Database file: group_1.280.1067312151
Database file type: file system
Database file size: 409600 512 byte blocks
--[grid@p19c01 ~]$ dbv file=group_1.280.1067312151 blocksize=512
DBVERIFY - Verification complete
Total Pages Examined : 409600
Total Pages Processed (Data) : 0
Total Pages Failing (Data) : 0
Total Pages Processed (Index): 0
Total Pages Failing (Index): 0
Total Pages Processed (Other): 0
Total Pages Processed (Seg) : 0
Total Pages Failing (Seg) : 0
Total Pages Empty : 0
Total Pages Marked Corrupt : 409600
Total Pages Influx : 190957
Total Pages Encrypted : 0
Highest block SCN : 0 (0.0)
--查看归档日志
[grid@p19c01 ~]$ dbv file=thread_1_seq_8.295.1067503735 blocksize=512 logfile=archdbv.log feedback=100
[grid@p19c01 ~]$ cat archdbv.log
DBVERIFY - Verification complete
Total Pages Examined : 42293
Total Pages Processed (Data) : 0
Total Pages Failing (Data) : 0
Total Pages Processed (Index): 0
Total Pages Failing (Index): 0
Total Pages Processed (Other): 0
Total Pages Processed (Seg) : 0
Total Pages Failing (Seg) : 0
Total Pages Empty : 0
Total Pages Marked Corrupt : 42293
Total Pages Influx : 12885
Total Pages Encrypted : 0
Highest block SCN : 0 (0.0)
