t.Errorf("Expecting region `us-east-1` found %s", globalSite.Region())
	}

	// Set new region and verify.
	config.SetRegion(globalServerConfig, "us-west-1")
	site, err := config.LookupSite(
		globalServerConfig[config.SiteSubSys][config.Default],
		globalServerConfig[config.RegionSubSys][config.Default],
	)
	if err != nil {
		t.Fatal(err)
	}
	if site.Region() != "us-west-1" {

	globalServerConfigMu sync.RWMutex
)

func validateSubSysConfig(ctx context.Context, s config.Config, subSys string, objAPI ObjectLayer) error {
	switch subSys {
	case config.SiteSubSys:
		if _, err := config.LookupSite(s[config.SiteSubSys][config.Default], s[config.RegionSubSys][config.Default]); err != nil {
			return err
		}
	case config.APISubSys:
		if _, err := api.LookupConfig(s[config.APISubSys][config.Default]); err != nil {

// letter. At least 2 characters long.
var validSiteNameRegex = regexp.MustCompile("^[a-z][a-z0-9-]+$")

// LookupSite - get site related configuration. Loads configuration from legacy
// region sub-system as well.
func LookupSite(siteKV KVS, regionKV KVS) (s Site, err error) {
	if err = CheckValidKeys(SiteSubSys, siteKV, DefaultSiteKVS); err != nil {
		return
	}