What is a valid filename for VirtualCdromIsoBackingInfo

Hi,

I'm trying to create a VM using the API that will mount an ISO when the VM is created.  I have the following snippet of code in my PERL script:

=== Start code snippet ===

my $ds_iso = undef;

my $dstores = Vim::get_views(mo_ref_array => $host_view->datastore);

foreach (@$dstores) {

if ($_->{name} eq 'ISOS') {

   $ds_iso = $_;

   last;

}

}

my $cd_backing_info = VirtualCdromIsoBackingInfo->new(

       datastore => $ds_iso;

       filename => 'blank.iso');

=== End code snippet ===

Whenever I run my script though, I get the following error messages:

Argument filename is not valid at /usr/share/perl5/VMware/VICommon.pm line 2492

     ComplexType::arg_validation('VirtualCdromIsoBackingInfo', 'filename' blank.iso', 'datastore', 'Datastore=HASH(0x...)') called at /usr/share/perl5/VMware/VICommon.pm line 2464

     ComplextType::new('VirtualCdromIsoBackingInfo' 'datastore', 'Datastore=HASH(0x...)', 'filename', 'blank.iso') called at createvm.pl line 100

For the "filename => 'blank.iso'" above, I've tried "blank.iso", "[ISOS]/blank.iso", and "/vmfs/volumes/_uuid_/blank.iso".  All of them give the same error message.

What is a valid filename that I can use here?

BTW, I've confirmed.  The ISO file, blank.iso, is at the top level of my "[ISOS]" datastore.

Thank you in advance.

Lewis