}

	// We know XFS already supports O_DIRECT no need to check.
	if fsType == "XFS" {
		return nil
	}

	// For all other FS pay the price of not using our recommended filesystem.

	// Check if backend is writable and supports O_DIRECT
	uuid := mustGetUUID()
	filePath := pathJoin(s.drivePath, minioMetaTmpDeletedBucket, ".writable-check-"+uuid+".tmp")

	// Create top level directories if they don't exist.

		},
		// Test case - 4
		// Check for presigned.
		{
			req: &http.Request{
				URL: &url.URL{
					Host:     "127.0.0.1:9000",
					Scheme:   httpScheme,
					Path:     SlashSeparator,
					RawQuery: "X-Amz-Credential=EXAMPLEINVALIDEXAMPL%2Fs3%2F20160314%2Fus-east-1",
				},
			},
			authT: authTypePresigned,
		},
		// Test case - 5
		// Check for post policy.
		{
			req: &http.Request{

	config.Lock()
	defer config.Unlock()

	// check if tier name is in all caps
	tierName := tier.Name
	if tierName != strings.ToUpper(tierName) {
		return errTierNameNotUppercase
	}

	// check if tier name already in use
	if _, exists := config.isTierNameInUse(tierName); exists {
		return errTierAlreadyExists
	}

	update := r.Form.Get("update") == "true"

	// Get current object layer instance.
	objectAPI, _ := validateAdminReq(ctx, w, r, policy.SetBucketTargetAction)
	if objectAPI == nil {
		return
	}

	// Check if bucket exists.
	if _, err := objectAPI.GetBucketInfo(ctx, bucket, BucketOptions{}); err != nil {
		writeErrorResponseJSON(ctx, w, toAPIError(ctx, err), r.URL)
		return
	}

in the event of a failed command. {{- if .Values.configPathmc }} MC_CONFIG_DIR="{{ .Values.configPathmc }}" MC="/usr/bin/mc --insecure --config-dir ${MC_CONFIG_DIR}" {{- else }} MC="/usr/bin/mc --insecure" {{- end }} # connectToMinio # Use a check-sleep-check loop to wait for MinIO service to be available connectToMinio() { SCHEME=$1 ATTEMPTS=0 ; LIMIT=29 ; # Allow 30 attempts set -e ; # fail if we can't read the keys. ACCESS=$(cat /config/rootUser) ; SECRET=$(cat /config/rootPassword) ; set +e ;...

in the event of a failed command. {{- if .Values.configPathmc }} MC_CONFIG_DIR="{{ .Values.configPathmc }}" MC="/usr/bin/mc --insecure --config-dir ${MC_CONFIG_DIR}" {{- else }} MC="/usr/bin/mc --insecure" {{- end }} # connectToMinio # Use a check-sleep-check loop to wait for MinIO service to be available connectToMinio() { SCHEME=$1 ATTEMPTS=0 ; LIMIT=29 ; # Allow 30 attempts set -e ; # fail if we can't read the keys. ACCESS=$(cat /config/rootUser) ; SECRET=$(cat /config/rootPassword) ; set +e ;...

in the event of a failed command. {{- if .Values.configPathmc }} MC_CONFIG_DIR="{{ .Values.configPathmc }}" MC="/usr/bin/mc --insecure --config-dir ${MC_CONFIG_DIR}" {{- else }} MC="/usr/bin/mc --insecure" {{- end }} # connectToMinio # Use a check-sleep-check loop to wait for MinIO service to be available connectToMinio() { SCHEME=$1 ATTEMPTS=0 ; LIMIT=29 ; # Allow 30 attempts set -e ; # fail if we can't read the keys. ACCESS=$(cat /config/rootUser) ; SECRET=$(cat /config/rootPassword) ; set +e ;...

		return false
	}

	if err := storageServerRequestValidate(r); err != nil {
		s.writeErrorResponse(w, err)
		return false
	}

	return true
}

// IsValid - To authenticate and check if the disk-id in the request corresponds to the underlying disk.
func (s *storageRESTServer) IsValid(w http.ResponseWriter, r *http.Request) bool {
	if !s.IsAuthValid(w, r) {
		return false
	}

	_, found := cache.iamUsersMap[accessKey]

	// Check for regular user access key
	if !found {
		store.loadUser(ctx, accessKey, regUser, cache.iamUsersMap)
		if _, found = cache.iamUsersMap[accessKey]; found {
			// load mapped policies
			store.loadMappedPolicyWithRetry(ctx, accessKey, regUser, false, cache.iamUserPolicyMap, 3)
		}
	}

	// Check for service account
	if !found {

X-Minio-Write-Quorum: 3
X-Amz-Request-Id: 16239D6AB80EBECF
X-Xss-Protection: 1; mode=block
Date: Tue, 21 Jul 2020 00:36:14 GMT
```

### Checking cluster health for maintenance

You may query the cluster probe endpoint to check if the node which received the request can be taken down for maintenance, if the server replies back '412 Precondition Failed' this means you will lose HA. '200 OK' means you are okay to proceed.

```