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Date: Thu, 26 Aug 2010 11:27:02 -0400
From: Jim Rees <rees@umich.edu>
To: Chuck Lever <chuck.lever@oracle.com>
Cc: Neil Brown <neilb@suse.de>,
        Linux NFS Mailing list <linux-nfs@vger.kernel.org>
Subject: Re: mount.nfs: protocol fallback when server doesn't support TCP
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Chuck Lever wrote:

  On Aug 25, 2010, at 10:06 PM, Neil Brown wrote:
  > Maybe the ideal would be to do a portmap probe and only fall back to v3 if
  > portmap confirm that v3 is supported and v4 isn't.

  What are the risks of checking portmap in this case?  That seems like it
  would give a better chance of a desirable outcome.

In general, portmap can't confirm that v4 isn't available, only that v3 is.
Right?