pfSense

After upgrading from 1.2.3 to 2.1 the rrd traffic & packets graphs no longer work. However graphs are OK if upgrading to 2.0.1

Further investigation shows that upgrade_080_to_081 is failing to update these graphs.
From the system.log:
Oct 24 15:31:55 pfsense php: : The command '/usr/bin/nice -n20 /usr/local/bin/rrdtool restore -f /tmp/lan-traffic.rrd.new.xml /var/db/rrd//lan-traffic.r
rd 2>&1' returned exit code '1', the output was 'ERROR: No <v> tag found'

Examination of /tmp/lan-traffic.rrd.new.xml shows that conversion of one of the databases is incomplete.
<row>
<v> NaN </v>
<v> NaN </v>
<v> NaN </v>
<v> NaN </v>
<v>0.0000000000e+00 </v>
<v>0.0000000000e+00 </v>
<v>0.0000000000e+00 </v>
<v>0.0000000000e+00 </v>
</row>
<row>
<v> NaN </v>
<v> NaN </v>
<v> NaN </v>
<v> NaN </v>
<v>0.0000000000e+00 </v>
<v>0.0000000000e+00 </v>
<v>0.0000000000e+00 </v>
<v>0.0000000000e+00 </v>
</row>
<row>
<v> NaN </v>
<v> NaN </v>
<v> NaN </v>
<v> NaN </v>
</row>
<row>
<v> NaN </v>
<v> NaN </v>
<v> NaN </v>
<v> NaN </v>
</row>
I added tracing to migrate_rrd_format in /etc/inc/rrd.inc:
$rowcountold = count($rrdoldxml['rra'][$i]['database']['row']);
$rowcountnew = count($rrdnewxml['rra'][$i]['database']['row']);
$rowcountdiff = $rowcountnew - $rowcountold;
echo "rowcountdiff $rowcountdiff\n";
and repeated the upgrade manually. This resulted in repeated output of:
rowcountdiff 0
rowcountdiff 0
rowcountdiff -2000
rowcountdiff 0
so it appears that one of the old databases is larger that the new one and this is not handled by the following script.