looks like it is related to the Vallard code changes

I think Cao Li was referring Jarrod B Johnson instead of Vallard. The issue resides in esx.pm subroutine: xCAT_plugin::esx::preprocess_request:

esx.pm Lines:
unless ($request) { return; }
if ($request->{command}->[0] eq 'copycd')
{ #don't farm out copycd
return [$request];
..

The request was cleared in sles.pm/anaconda.pm/windows.pm by that:

%{$request} = ();    #clear request we've got it.

line "unless ($request) { return; } " does not much, but if ($request->{command}->[0] eq 'copycd') will result in perl syntax issue.
hv4plus_xcat03:~ # XCATBYPASS=1 copycds /iso/11/SLES-11-DVD-ppc64-GM-DVD1.iso
...
Use of uninitialized value in string eq at /opt/xcat/lib/perl/xCAT_plugin/esx.pm line 147.
Use of uninitialized value in string eq at /opt/xcat/lib/perl/xCAT_plugin/esx.pm line 147.
DBD::mysql::db table_info failed: MySQL server has gone away at /opt/xcat/lib/perl/xCAT/Table.pm line 314.
DBD::mysql::db table_info failed: MySQL server has gone away at /opt/xcat/lib/perl/xCAT/Table.pm line 314.
Cannot open vm table
hv4plus_xcat03:~ #

Fixed in svn rev 4316

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