Auto Numbering for Existing Records ServiceNow

var gr = new GlideRecord("cmdb_ci_computer"); 
  gr.orderBy('sys_created_on'); 
  gr.query(); 
  while (gr.next()) { 
     var nm = new NumberManager('cmdb_ci_computer'); 
     gr.u_number = nm.getNextObjNumberPadded(); 
     gr.autoSysFields(false);   // Do not update sys_updated_on, sys_updated_by, and sys_mod_count 
     gr.setWorkflow(false);       // Do not run any other business rules 
     gr.update(); 
  }