[Lustre-discuss] Object index

[DEGREMONT Aurelien]

Hello

I'm trying to analyze an OST with few thousands of object and find where they belong to.
Mounting this OST with ldiskfs and using ll_decode_filter_fid tells me that.

-Most of these object do not have a fid EA back pointer. Does that means they are not used?
-Some of them have good results, and the man page says that
"For objects with MDT parent sequence numbers above 0x200000000, this indicates that the FID needs to be mapped via the 
MDT Object Index (OI) file on the MDT".
How do I do this mapping? I found some iam utilities but they do not seems to be ok, and I'm afraid IAM userspace code 
has been deactivated.

How can I know if those files could be removed without risk.
I previously checked that "lfs find" did not find any other files with object on this specific OST I'm working on.

Thanks

Aurélien Degrémont