in console when upgrade 2.0: Stopping couchbase-serverNOTE: shutdown failed {badrpc,nodedown}

I get error at the end of the log when I upgrade 2.0 (for instance 1409 ->1416, use 'rpm -U'). It does not matter if I stopped it before or I updated the running server

I note that there was a similar bug on 1.8.1: MB-5239
upgrading 1.8.0r-55 ubuntu cluster to 1.8.1-798-rel wipes out the config and data files

[root@localhost tmp]# rpm -U couchbase-server-enterprise_x86_64_2.0.0-1416-rel.rpm
Stopping couchbase-server ...
Stopping couchbase-server
=INFO REPORT==== 8-Jul-2012::01:31:49 ===
Initiated server shutdown** at node ns_1@10.3.121.116 **

=INFO REPORT==== 8-Jul-2012::01:32:09 ===
Stopped ns_server application** at node ns_1@10.3.121.116 **

Upgrading couchbase-server ...
  /opt/couchbase/bin/cbupgrade -c /opt/couchbase/var/lib/couchbase/config -a yes
Automatic mode: running without interactive questions or confirmations.
Upgrading your Couchbase Server to 2.0.0-1416-rel.
The upgrade process might take awhile.
Analysing...
Previous config.dat file is /opt/couchbase/var/lib/couchbase/config/config.dat
Target node: ns_1@127.0.0.1
Done: previous node configuration is empty.
Starting couchbase-server[ OK ]

You have successfully installed Couchbase Server.
Please browse to http://localhost.localdomain:8091/ to configure your server.
Please refer to http://couchbase.com for additional resources.

Please note that you have to update your firewall configuration to
allow connections to the following ports: 11211, 11210, 4369,
8091, 8092 and from 21100-to-21299.

By using this software you agree to the End User License Agreement.
See /opt/couchbase/LICENSE.txt.

Stopping couchbase-serverNOTE: shutdown failed
{badrpc,nodedown}