Oracle Restoring a damaged disk header using KFED.

Posted by PDSERVICE on Nov 09, 2016 In

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Applies to:

Oracle Server - Enterprise Edition - Version 11.1.0.7 and later

Information in this document applies to any platform.

Starting with 11.1.0.7, every time an I/O write is submitted to the ASM disk header (AU 0, blknum 0), it is copied to Allocation Unit 1, into the second to

last block. So you can simply and easily recreate the ASM disk header using KFED with the REPAIR option.

Goal

Restore an ASM disk header that has been damaged or corrupted.

Fix

In order to restore a damaged or corrupted ASM disk header, issue the following kfed command:

kfed op=repair dev=<device name> ausz=<allocation unit size>

where "device name" is the path name of the disk to be repaired and "allocation unit size" is the AU size of the ASM disk group. The AU size is needed

in order for kfed to calculate the location of the backup copy of the disk header, which is stored in the second to last block of AU 1.

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Oracle Restoring a damaged disk header using KFED.