PRM-DUL on ASM

Posted by PDSERVICE on Apr 18, 2016 In

PRM-DUL works on oracle ASM .

PRM now can support two kinds of ASM data recovery：

Once Disk Group cannot be mounted, PRM can read metadata, and clone ASM file from Disk Group.
Once Disk Group cannot be mounted, PRM can read ASM file and extract data, which supports both traditional data export and data bridge.

Basically you need to provide the disk names in GUL and then PRM-DUL will be able to read and understand.

CASE 6: Copy DB datafile from damaged ASM diskgroup

The Company D begins to uses ASM instead of other file system. Since there are many bugs in the version 11.2.0.1that it uses, causing that ASM DISKGROUP cannot be mounted and still does not work after repairing ASM Disk Header.

In this case, user can use the ASM Files Clone feature of PRM to rescue datafile from damaged ASM DiskGroup directly.

Open main interface, and select ASM File(s) Clone under Tools:

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Enter ASM Disks Window, click SELECT…to add ASM Disks, for example:

/dev/asm-disk5(linux). Then click ASM analyze.

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ASM Files Clone will analyze the specified ASM Disk header, in order to find corresponding files in Disk group and the File Extent Map. All of the information will be recorded into PRM embedded database for future use. PRM can collect, analyze and store all Metadata, and improve the basic functions of PRM in various forms, showing to users by diagram.

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After ASM Analyze, PRM will find the file list in Disk groups. So users can select the datafile/archivelog which need to be cloned to destination folder

Click ASM Clone to start file cloning…

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There is a progress bar of file cloning.

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ASM File Clone log as below:

Preparing selected files…Cloning +DATA2/ASMDB1/DATAFILE/TBS2.256.839732369:……………………..1024MB………………………………..2048MB………………………………..3072MB

………………………………….4096MB

………………………………..5120MB

………………………………….6144MB

……………………………….7168MB

…………………………………8192MB

…………………………………9216MB

…………………………………10240MB

…………………………………11264MB

…………………………………..12288MB

…………………………………….13312MB

…………………………….14336MB

……………………………………..15360MB

……………………………….16384MB

…………………………………17408MB

…………………………………18432MB

…………………………………………………………………………………………….19456MB

……………………………………

Cloned size for this file (in byte): 21475885056

Cloned successfully!

Cloning +DATA2/ASMDB1/ARCHIVELOG/2014_02_17/thread_1_seq_47.257.839732751:

……

Cloned size for this file (in byte): 29360128

Cloned successfully!

Cloning +DATA2/ASMDB1/ARCHIVELOG/2014_02_17/thread_1_seq_48.258.839732751:

……

Cloned size for this file (in byte): 1048576

Cloned successfully!

All selected files were cloned done.

It is necessary to validate cloned data via the “dbv” or “rman validate” command, for example:

rman target /RMAN> catalog datafilecopy ‘/home/oracle/asm_clone/TBS2.256.839732369.dbf’;cataloged datafile copy

datafile copy file name=/home/oracle/asm_clone/TBS2.256.839732369.dbf RECID=2 STAMP=839750901

RMAN> validate datafilecopy ‘/home/oracle/asm_clone/TBS2.256.839732369.dbf’;

Starting validate at 17-FEB-14

using channel ORA_DISK_1

channel ORA_DISK_1: starting validation of datafile

channel ORA_DISK_1: including datafile copy of datafile 00016 in backup set

input file name=/home/oracle/asm_clone/TBS2.256.839732369.dbf

channel ORA_DISK_1: validation complete, elapsed time: 00:03:35

List of Datafile Copies

=======================

File Status Marked Corrupt Empty Blocks Blocks Examined High SCN

—- —— ————– ———— ————— ———-

16 OK 0 2621313 2621440 1945051

File Name: /home/oracle/asm_clone/TBS2.256.839732369.dbf

Block Type Blocks Failing Blocks Processed

———- ————– —————-

Data 0 0

Index 0 0

Other 0 127

Finished validate at 17-FEB-14

How to use PRM in ASM environment with ASMLIB?

asmlib related ASM DISK will be stored in OS as ll /dev/oracleasm/disks.

For example: Add files under /dev/oracleasm/disks into PRM ASM DISK

$ll /dev/oracleasm/diskstotal 0brw-rw—- 1 oracle dba 8, 97 Apr 28 15:20 VOL001brw-rw—- 1 oracle dba 8, 81 Apr 28 15:20 VOL002brw-rw—- 1 oracle dba 8, 65 Apr 28 15:20 VOL003brw-rw—- 1 oracle dba 8, 49 Apr 28 15:20 VOL004

brw-rw—- 1 oracle dba 8, 33 Apr 28 15:20 VOL005

brw-rw—- 1 oracle dba 8, 17 Apr 28 15:20 VOL006

brw-rw—- 1 oracle dba 8, 129 Apr 28 15:20 VOL007

brw-rw—- 1 oracle dba 8, 113 Apr 28 15:20 VOL008

CASE 7: DB stored in ASM cannot be opened

One of CRM database in company D can’t be opened due to I/O error in a few disks that are added into ASM diskgroup, which generated some corrupted block in system tablespace datafile, and caused DB cannot be opened.

In this case, we can use PRM ASM Diskgroup to clone all datafile out of ASM.

Or, users can also use “Dictionary Mode(ASM)” to recover data from this ASM environment . Steps are as below:

Recovery Wizard
Dictionary Mode(ASM)
Add ASM DISK (all ASM DISK in the ASM Disk Group that you want to recover)
Click ASM analyze
Select suitable Endian
Select the needed datafile from the datafile lists by ASM analyze, or click “select all”
Click “load”, following steps are the same with case3

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CASE 8: Recovery of Mistakenly deleted or Lost system tablespace in ASM

The operation staff of Company D deleted system tablespace FILE#=1 datafile and user tablespace by mistake, causing the database cannot be opened.

In this case, users can use” Non-Dictionary Mode (ASM)” to recover data.

Steps are as below:

Recovery Wizard
Non-Dictionary Mode (ASM)
Add necessary ASM Disk
Click ASM analyze
Select the suitable Endian and Character set. (Manually select character set due to Non-Dictionary Mode)
Select all data file, or click “Select all”
Click “scan”, following steps are the same with Case 3

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PRM-DUL on ASM

PRM-DUL on ASM