How to retrieve data files from ASM in Oracle

Most of the time, because ASM does not start properly, data loss is caused. Here are two ways to retrieve data files from ASM

I. Using the AMDU tool

Amdu is a free tool in Oracle 11g that analyzes the metadata of the ASM Disk group and extracts data files from a disk group that cannot be mount "note:553639.1 placeholder for AMDU binaries and Using with ASM 10g "clearly stated: Amdu can also be used for 10g and provides a version of the various operating systems available for use in 10g amdu for everyone to download."

1. Set Ld_library_path

Rac1-> Export LD_LIBRARY_PATH=/TMP/AMDU

2. View ASM Disk Information

rac1->./amdu-diskstring '/dev/raw/raw* '

amdu_2012_03_05_03_17_19/

Rac1-> CD amdu_2012_03_05_03_17_19/

Rac1-> ls

Report.txt

rac1-> more Report.txt

-*-amdu-*-

Amdu Settings ********************************

Oracle_home =/u01/app/oracle/product/10.2.0/db_1

System Name:linux

Node NAME:RAC1

Release:2.6.9-89.0.0.0.1.elhugemem

Version: #1 SMP Tue may 04:38:38 EDT 2009

machine:i686

Amdu run:05-mar-12 03:17:19

Endianess:1

---------------------------------Operations---------------------------------

More Wonderful content: http://www.bianceng.cn/database/Oracle/

-------------------------------Disk Selection-------------------------------

-diskstring '/dev/raw/raw* '

------------------------------Reading Control-------------------------------

-------------------------------Output Control-------------------------------

DISCOVERY **********************************

-----------------------------DISK N0001------------------------------

Disk Path:/dev/raw/raw23

Unique Disk ID:

Disk Label:

Physical Sector size:512 bytes

Disk size:156 Megabytes

* * Not A VALID ASM DISK HEADER. Bad VALUE in FIELD blksize_kfdhdb * *

-----------------------------DISK N0002------------------------------

Disk Path:/DEV/RAW/RAW11

Unique Disk ID:

Disk Label:

Physical Sector size:512 bytes

Disk size:156 Megabytes

* * Not A VALID ASM DISK HEADER. Bad VALUE in FIELD blksize_kfdhdb * *

-----------------------------DISK N0003------------------------------

Disk Path:/dev/raw/raw32

Unique Disk ID:

Disk Label:

Physical Sector size:512 bytes

Disk size:156 Megabytes

* * Not A VALID ASM DISK HEADER. Bad VALUE in FIELD blksize_kfdhdb * *

-----------------------------DISK N0004------------------------------

Disk Path:/dev/raw/raw31

Unique Disk ID:

Disk Label:

Physical Sector size:512 bytes

Disk size:156 Megabytes

* * Not A VALID ASM DISK HEADER. Bad VALUE in FIELD blksize_kfdhdb * *

-----------------------------DISK N0005------------------------------

Disk Path:/dev/raw/raw12

Unique Disk ID:

Disk Label:

Physical Sector size:512 bytes

Disk size:156 Megabytes

* * Not A VALID ASM DISK HEADER. Bad VALUE in FIELD blksize_kfdhdb * *

-----------------------------DISK N0006------------------------------

Disk Path:/DEV/RAW/RAW2

Unique Disk ID:

Disk Label:

Physical Sector size:512 bytes

Disk size:1976 Megabytes

Group Name:data

Disk name:data_0001

Failure Group name:data_0001

Disk number:1

Header Status:3

Disk Creation Time:2012/03/01 22:32:39.289000

Last Mount time:2012/03/05 02:10:02.771000

Compatibility version:0x0a100000

Disk Sector size:512 bytes

Disk size in aus:1976 AUs

Group redundancy:1

Metadata block size:4096 bytes

AU size:1048576 bytes

stride:113792 AUs

Group Creation Time:2012/03/01 22:32:39.221000

File 1 Block 1 Location:au 0

-----------------------------DISK N0007------------------------------

Disk Path:/DEV/RAW/RAW1

Unique Disk ID:

Disk Label:

Physical Sector size:512 bytes

Disk size:3137 Megabytes

Group Name:data

Disk name:data_0000

Failure Group name:data_0000

Disk number:0

Header Status:3

Disk Creation Time:2012/03/01 22:32:39.289000

Last Mount time:2012/03/05 02:10:02.771000

Compatibility version:0x0a100000

Disk Sector size:512 bytes

Disk size in aus:3137 AUs

Group redundancy:1

Metadata block size:4096 bytes

AU size:1048576 bytes

stride:113792 AUs