PROBLEM: Duplicated entries in large NFS shared directory

Bruce Guenter lists-ext3-users at
Tue Dec 11 22:15:04 UTC 2007


I have a large directory (almost 40,000 entries) on an ext3 filesystem
that is shared over NFS.  I discovered recently when listing the
directory on the client, one of the files appears twice.  The same file
does not appear twice on the server.

I did a capture using WireShark, and discovered that the offending file
name is being sent twice -- once as the last entry in a readdir reply
packet and then again as the first entry in the next readdir reply.

If I'm reading the trace right, the readdir call sends the cookie for
the last entry in the previous readdir reply and the server responds
with the next set of entries.  In this case, the server responds with
the entry containing the same cookie again.

The server is running vanilla  I would be happy to provide any
further information that would help resolve this bug.

I posted this to the NFS maintainers, and Neil Brown suggested:

> My guess is that you have lucked-out and got two directory entries
> that hash to the same value, and they appear either side of a readdir
> block boundary.
> It is an awkward designed limitation of ext3 that is rarely a problem
> and could possibly be worked around to some extent...
Bruce Guenter <bruce at>      
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 189 bytes
Desc: not available
URL: <>

More information about the Ext3-users mailing list