Oracle DBVERIFY ( DBV ) Utility | Restore Validate & Detect Corruption

I will explain Oracle DBVERIFY ( DBV ) Utility in this post which Validate & Detect Corruption and Verify Oracle Files.

Oracle DBVERIFY ( DBV ) Utility

DBV ( DBVERIFY ) is external utility of Oracle database that performs a physical data structure integrity check of Oracle files ( Datafile, Archivelog, Backups )

Everytime you need verifying the datafiles, archivelogs or backup files against the Disaster scenarios.

Even though you have backup, when you want to restore these backup , you may see the corruption of backup files. So Restore validate and DBV Utility should be done periodically.

You can read the following post to learn how to perform Restore Validate operation in Oracle database.

Restore Validate via RMAN | Oracle RMAN ( Recovery Manager ) Restore Recover Tutorials -1

Sometimes You can get ” ORA-19566: exceeded limit of 0 corrupt blocks for file  error ” during RMAN Backup or You can see the Block corruptions in the database.

You can use DBV Tool and Performing an DBV on the above file shows a corrupt block.

dbv file=/<path>/<datafilename>.dbf blocksize=16384

DBVERIFY: Release 9.2.0.4.0 - Production on Thu Aug 30 18:06:59 2007

Copyright (c) 1982, 2002, Oracle Corporation.  All rights reserved.

DBVERIFY - Verification starting : FILE = /<path>/<datafilename>.dbf


Page 91880 is influx - most likely media corrupt
***
Corrupt block relative dba: 0x048166e8 (file 18, block 91880)
Fractured block found during dbv:
Data in bad block -
 type: 0 format: 0 rdba: 0x00000000
 last change scn: 0x0000.00000000 seq: 0x0 flg: 0x00
 consistency value in tail: 0x00000001
 check value in block header: 0x0, block  checksum disabled
 spare1: 0x0, spare2: 0x0, spare3: 0x0
***

DBVERIFY - Verification complete

Total Pages Examined         : 128000
Total Pages Processed (Data) : 10475
Total Pages Failing   (Data) : 0
Total Pages Processed (Index): 1154
Total Pages Failing   (Index): 0
Total Pages Processed (Other): 645
Total Pages Processed (Seg)  : 0
Total Pages Failing   (Seg)  : 0
Total Pages Empty            : 115725
Total Pages Marked Corrupt   : 1
Total Pages Influx           : 1

[oracle@msdbadm01 ~]$ dbv file=+DATA/MSDB/datafile/test01.dbf
 
DBVERIFY: Release 12.1.0.2.0 - Production on Tue Jul 19 12:49:19 2016
 
Copyright (c) 1982, 2014, Oracle and/or its affiliates.  All rights reserved.
 
DBVERIFY - Verification starting : FILE = +DATA/MSDB/datafile/test01.dbf
Page 131 is marked corrupt
Corrupt block relative dba: 0x01400083 (file 7, block 2241925)
Completely zero block found during dbv:
 
 
 
DBVERIFY - Verification complete
 
Total Pages Examined         : 640
Total Pages Processed (Data) : 4
Total Pages Failing   (Data) : 0
Total Pages Processed (Index): 0
Total Pages Failing   (Index): 0
Total Pages Processed (Other): 130
Total Pages Processed (Seg)  : 0
Total Pages Failing   (Seg)  : 0
Total Pages Empty            : 505
Total Pages Marked Corrupt   : 1
Total Pages Influx           : 0
Total Pages Encrypted        : 0
Highest block SCN            : 2631270 (0.2631270)

If you have block corruptions in your database, then you can read the following post to repair these block corruptions.

ORA-01578: ORACLE data block corrupted (file # string, block # string) and How to Solve Block Corruption Error

You can use the DBV utility for the Backup files to see if they are corrupted or not as follows.

[MSDB1]/home/oracle $ dbv file='/zfssa/MSDB/MSDB_full01_c03/MSDB_COPY_data_D-MSDB_I-2054866743_TS-UNDOTBS3_FNO-41_obvjqo6j' blocksize=16384

DBVERIFY: Release 19.0.0.0.0 - Production on Sat Feb 13 14:24:25 2021

Copyright (c) 1982, 2019, Oracle and/or its affiliates. All rights reserved.

DBVERIFY - Verification starting : FILE = /zfssa/MSDB/MSDB_full01_c03/MSDB_COPY_data_D-MSDB_I-2054866743_TS-UNDOTBS3_FNO-41_obvjqo6j
Page 952063 is influx - most likely media corrupt
Corrupt block relative dba: 0x0a4e86ff (file 41, block 952063)
Fractured block found during dbv: 
Data in bad block:
type: 2 format: 2 rdba: 0x0a4e86ff
last change scn: 0x0000.0f68.b92c89c7 seq: 0x1 flg: 0x04
spare3: 0x0
consistency value in tail: 0x50003c00
check value in block header: 0x4e50
computed block checksum: 0x7d4a

Do you want to learn more details about RMAN, then Click this Link and read the articles.

RMAN Tutorial | Backup, Restore and Recovery Tutorials For Beginner Oracle DBA