cfg, err := readServerConfig(ctx, objectAPI, nil)
	if err != nil {
		writeErrorResponseJSON(ctx, w, toAdminAPIErr(ctx, err), r.URL)
		return
	}

	cfgKey := fmt.Sprintf("%s:%s", subSys, cfgName)
	if cfgName == madmin.Default {
		cfgKey = subSys
	}
	if err = cfg.DelKVS(cfgKey); err != nil {
		writeErrorResponseJSON(ctx, w, toAdminAPIErr(ctx, err), r.URL)
		return
	}
	if err = validateConfig(ctx, cfg, subSys); err != nil {