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Oracle ASM data header issue

Oracle ASM data header issue

Posted by PDSERVICE on Mar 07, 2020 In
Kindly note that we have issue on your tool, we have 2 disk group asm, archive and data. 
 
 This disk data has an issue in header / data dictionary. It's mounted with empty datafile after we use asmca add disks. 
 
 Can you please advise if your tool support this case or not? 
 
 
 
 
 if it lost metadata data , it can not be loaded  via prm directly .
 
pls reference prmscan oracle block fragmentation recovery   https://youtu.be/skH9nJOvIkQ, have to scan the disk and merge block into datafiles , and then use prm-dul to unload data.
 
 
 
 
How to download this tool, I did not find link for this scan tool
 
 
prm scan is bundle with prm , you need to purchase one prm license , after that you will receive it.
 
 
for filesystem , it may lost some block due to filesystem allocation unit may be 4k size .
for ASM , the AU allocation unit is always 1M , it means prm scan can get almost all block resides on asm disk , if it exits.
 
Even if we recreate asm with differnent name by mistake? Using asmca? Now we can access asm with no data inside. But we are sure that just header was new. 
 
This tool can build header and dictionary again? 
 
 
 
no , you recreate the asm disk group ,that means you rewrite some metadata into disk header and some other place. but this won't override most of oracle data block .
 
for example , you have datafiles on your filesystem , but you do quick format to that filesystem , but you can scan the disk , and get datafiles back .
 
 
reference video:
 
prmscan oracle block fragmentation recovery                             https://youtu.be/skH9nJOvIkQ
prmscan extract datafile from oracle asm diskgroup               https://youtu.be/Btt3kpPm3Qs
 
 
 

 

Kindly note that as discussed before with our team we have below issue on ASM disk header  :

 

We have issue that the team by mistake recreate ask disk and run asmca tool on this disk. The header and data dictionary for this disk was overwrite. Disk group  mounted now with empty dictionary. 

We are sure the data still exist. But without header we are unable to reach the datafiles.

If disk lost metadata . it can not be loaded via prm directory , we have to scan the disk and merge block into datafiles. And then use prm-dul to unload data.

Can you please provide us with prmscan tool URL.