Thanks, Pbil.  We will certainly double check it and then add it to the
Orange-branch.  Just FYI:  we have a warning built into the config
generator that Berkeley 4.8 is now recommended.

Becky
-- 
Becky Ligon
HPC Admin Staff
PVFS/OrangeFS Developer
Clemson University
864-650-4065

> We found a case today where a PVFS server had somehow ended up with
> duplicate entries in its attr db.  The attached patch simply makes PVFS
> print a warning message (similar to existing warnings for corrupt
> entries) if it finds a duplicate key in the attr db.  The duplicates are
> then filtered out of the iterate_handles() results so that they don't
> cause trouble later in the handle ledger accounting or pvfs2-fsck.  It
> only handles the case where duplicate keys show up adjacent to each
> other in the db, but that is the most plausible scenario anyway since
> the keys are sorted.  The warning message looks like this:
>
> [E 05/11 21:19] Warning: got duplicate handle 12345678.
>
> I'm not sure what (if anything) happens later on if you keep running a
> server that has duplicate handle entries, but you can always clean one
> of them out if you want to using the pvfs2-remove-object utility.
>
> FWIW, Berkeley DB _does_ support duplicate keys, but its only supposed
> to be possible if you set explicit flags to enable that functionality
> (which PVFS does not do).  I'm not sure what led to this particular
> corruption, but these servers had experienced DB panics in the past
> while using Berkeley DB 4.3.  They have now been upgraded to use 4.8.
> Prior to this patch the servers with duplicate entries were generating
> an incorrect handle ledger on startup (skipping several valid handles),
> which caused pvfs2-fsck to fail when it tried to double check the handle
> count.  I imagine there were probably other side effects as well.
>
> Can someone sanity check this patch and commit it to the appropriate cvs
> branches if it looks Ok?
>
> thanks!
> -Phil
>
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>


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