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How to Dump or Extract a Raw Block From a File Stored in an ASM Diskgroup (Doc ID 603962.1)

Last updated on DECEMBER 18, 2019

Applies to:

Oracle Database Cloud Schema Service - Version N/A and later
Oracle Database Exadata Express Cloud Service - Version N/A and later
Oracle Database Exadata Cloud Machine - Version N/A and later
Oracle Cloud Infrastructure - Database Service - Version N/A and later
Oracle Database Backup Service - Version N/A and later
Information in this document applies to any platform.

Goal

To provide a simple mechanism to extract a particular block from a datafile stored in an ASM diskgroup. 

When database files are stored in file systems or raw devices, it is possible to use dd command to extract the particular block from the particular file.



When database files are stored in ASM, this is not possible because external tools like dd command can not be execute directly on the ASM files.  In addition, in order to extract the block using dd command, is required to identify the specific location on the disk where  the block  is located.  This requires running extra steps that make the procedure complex and exposed to errors.

The procedure can be used to extract blocks from any file stored in ASM.

Solution

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In this Document
Goal
Solution
 Dump the Block from Default Mirror
 Dump the Block from Mirror Copies
References

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