die "unknown version" if $params{version} &&
($params{version} < 0 || $params{version} > $params{dbfile}->backend_data) ;
my $path = $self->_filesystem_path($params{dbfile},$params{version});
die "unknown version" if $params{version} &&
($params{version} < 0 || $params{version} > $params{dbfile}->backend_data) ;
my $path = $self->_filesystem_path($params{dbfile},$params{version});