CreateMountTarget
Creates a mount target for a file system. You can then mount the file system on EC2 instances by using the mount target.
You can create one mount target in each Availability Zone in your VPC. All EC2 instances in a VPC within a given Availability Zone share a single mount target for a given file system. If you have multiple subnets in an Availability Zone, you create a mount target in one of the subnets. EC2 instances do not need to be in the same subnet as the mount target in order to access their file system.
You can create only one mount target for a One Zone file system.
You must create that mount target in the same Availability Zone in which the file system is
located. Use the AvailabilityZoneName
and AvailabiltyZoneId
properties in the DescribeFileSystems response object to get this
information. Use the subnetId
associated with the file system's Availability Zone
when creating the mount target.
For more information, see Amazon EFS: How it Works.
To create a mount target for a file system, the file system's lifecycle state must be
available
. For more information, see DescribeFileSystems.
In the request, provide the following:
-
The file system ID for which you are creating the mount target.
-
A subnet ID, which determines the following:
-
The VPC in which Amazon EFS creates the mount target
-
The Availability Zone in which Amazon EFS creates the mount target
-
The IP address range from which Amazon EFS selects the IP address of the mount target (if you don't specify an IP address in the request)
-
After creating the mount target, Amazon EFS returns a response that includes, a
MountTargetId
and an IpAddress
. You use this IP address when
mounting the file system in an EC2 instance. You can also use the mount target's DNS name
when mounting the file system. The EC2 instance on which you mount the file system by using
the mount target can resolve the mount target's DNS name to its IP address. For more
information, see How it Works:
Implementation Overview.
Note that you can create mount targets for a file system in only one VPC, and there can be only one mount target per Availability Zone. That is, if the file system already has one or more mount targets created for it, the subnet specified in the request to add another mount target must meet the following requirements:
-
Must belong to the same VPC as the subnets of the existing mount targets
-
Must not be in the same Availability Zone as any of the subnets of the existing mount targets
If the request satisfies the requirements, Amazon EFS does the following:
-
Creates a new mount target in the specified subnet.
-
Also creates a new network interface in the subnet as follows:
-
If the request provides an
IpAddress
, Amazon EFS assigns that IP address to the network interface. Otherwise, Amazon EFS assigns a free address in the subnet (in the same way that the Amazon EC2CreateNetworkInterface
call does when a request does not specify a primary private IP address). -
If the request provides
SecurityGroups
, this network interface is associated with those security groups. Otherwise, it belongs to the default security group for the subnet's VPC. -
Assigns the description
Mount target fsmt-id for file system fs-id
wherefsmt-id
is the mount target ID, andfs-id
is theFileSystemId
. -
Sets the
requesterManaged
property of the network interface totrue
, and therequesterId
value toEFS
.
Each Amazon EFS mount target has one corresponding requester-managed EC2 network interface. After the network interface is created, Amazon EFS sets the
NetworkInterfaceId
field in the mount target's description to the network interface ID, and theIpAddress
field to its address. If network interface creation fails, the entireCreateMountTarget
operation fails. -
Note
The CreateMountTarget
call returns only after creating the network
interface, but while the mount target state is still creating
, you can check
the mount target creation status by calling the DescribeMountTargets operation, which among other things returns the mount
target state.
We recommend that you create a mount target in each of the Availability Zones. There
are cost considerations for using a file system in an Availability Zone through a mount target
created in another Availability Zone. For more information, see Amazon EFS
This operation requires permissions for the following action on the file system:
-
elasticfilesystem:CreateMountTarget
This operation also requires permissions for the following Amazon EC2 actions:
-
ec2:DescribeSubnets
-
ec2:DescribeNetworkInterfaces
-
ec2:CreateNetworkInterface
Request Syntax
POST /2015-02-01/mount-targets HTTP/1.1
Content-type: application/json
{
"FileSystemId": "string
",
"IpAddress": "string
",
"SecurityGroups": [ "string
" ],
"SubnetId": "string
"
}
URI Request Parameters
The request does not use any URI parameters.
Request Body
The request accepts the following data in JSON format.
- FileSystemId
-
The ID of the file system for which to create the mount target.
Type: String
Length Constraints: Maximum length of 128.
Pattern:
^(arn:aws[-a-z]*:elasticfilesystem:[0-9a-z-:]+:file-system/fs-[0-9a-f]{8,40}|fs-[0-9a-f]{8,40})$
Required: Yes
- IpAddress
-
Valid IPv4 address within the address range of the specified subnet.
Type: String
Length Constraints: Minimum length of 7. Maximum length of 15.
Pattern:
^[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}$
Required: No
- SecurityGroups
-
Up to five VPC security group IDs, of the form
sg-xxxxxxxx
. These must be for the same VPC as subnet specified.Type: Array of strings
Array Members: Maximum number of 100 items.
Length Constraints: Minimum length of 11. Maximum length of 43.
Pattern:
^sg-[0-9a-f]{8,40}
Required: No
- SubnetId
-
The ID of the subnet to add the mount target in. For One Zone file systems, use the subnet that is associated with the file system's Availability Zone.
Type: String
Length Constraints: Minimum length of 15. Maximum length of 47.
Pattern:
^subnet-[0-9a-f]{8,40}$
Required: Yes
Response Syntax
HTTP/1.1 200
Content-type: application/json
{
"AvailabilityZoneId": "string",
"AvailabilityZoneName": "string",
"FileSystemId": "string",
"IpAddress": "string",
"LifeCycleState": "string",
"MountTargetId": "string",
"NetworkInterfaceId": "string",
"OwnerId": "string",
"SubnetId": "string",
"VpcId": "string"
}
Response Elements
If the action is successful, the service sends back an HTTP 200 response.
The following data is returned in JSON format by the service.
- AvailabilityZoneId
-
The unique and consistent identifier of the Availability Zone that the mount target resides in. For example,
use1-az1
is an AZ ID for the us-east-1 Region and it has the same location in every AWS account.Type: String
- AvailabilityZoneName
-
The name of the Availability Zone in which the mount target is located. Availability Zones are independently mapped to names for each AWS account. For example, the Availability Zone
us-east-1a
for your AWS account might not be the same location asus-east-1a
for another AWS account.Type: String
Length Constraints: Minimum length of 1. Maximum length of 64.
Pattern:
.+
- FileSystemId
-
The ID of the file system for which the mount target is intended.
Type: String
Length Constraints: Maximum length of 128.
Pattern:
^(arn:aws[-a-z]*:elasticfilesystem:[0-9a-z-:]+:file-system/fs-[0-9a-f]{8,40}|fs-[0-9a-f]{8,40})$
- IpAddress
-
Address at which the file system can be mounted by using the mount target.
Type: String
Length Constraints: Minimum length of 7. Maximum length of 15.
Pattern:
^[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}$
- LifeCycleState
-
Lifecycle state of the mount target.
Type: String
Valid Values:
creating | available | updating | deleting | deleted | error
- MountTargetId
-
System-assigned mount target ID.
Type: String
Length Constraints: Minimum length of 13. Maximum length of 45.
Pattern:
^fsmt-[0-9a-f]{8,40}$
- NetworkInterfaceId
-
The ID of the network interface that Amazon EFS created when it created the mount target.
Type: String
- OwnerId
-
AWS account ID that owns the resource.
Type: String
Length Constraints: Maximum length of 14.
Pattern:
^(\d{12})|(\d{4}-\d{4}-\d{4})$
- SubnetId
-
The ID of the mount target's subnet.
Type: String
Length Constraints: Minimum length of 15. Maximum length of 47.
Pattern:
^subnet-[0-9a-f]{8,40}$
- VpcId
-
The virtual private cloud (VPC) ID that the mount target is configured in.
Type: String
Errors
- AvailabilityZonesMismatch
-
Returned if the Availability Zone that was specified for a mount target is different from the Availability Zone that was specified for One Zone storage. For more information, see Regional and One Zone storage redundancy.
HTTP Status Code: 400
- BadRequest
-
Returned if the request is malformed or contains an error such as an invalid parameter value or a missing required parameter.
HTTP Status Code: 400
- FileSystemNotFound
-
Returned if the specified
FileSystemId
value doesn't exist in the requester's AWS account.HTTP Status Code: 404
- IncorrectFileSystemLifeCycleState
-
Returned if the file system's lifecycle state is not "available".
HTTP Status Code: 409
- InternalServerError
-
Returned if an error occurred on the server side.
HTTP Status Code: 500
- IpAddressInUse
-
Returned if the request specified an
IpAddress
that is already in use in the subnet.HTTP Status Code: 409
- MountTargetConflict
-
Returned if the mount target would violate one of the specified restrictions based on the file system's existing mount targets.
HTTP Status Code: 409
- NetworkInterfaceLimitExceeded
-
The calling account has reached the limit for elastic network interfaces for the specific AWS Region. Either delete some network interfaces or request that the account quota be raised. For more information, see Amazon VPC Quotas in the Amazon VPC User Guide (see the Network interfaces per Region entry in the Network interfaces table).
HTTP Status Code: 409
- NoFreeAddressesInSubnet
-
Returned if
IpAddress
was not specified in the request and there are no free IP addresses in the subnet.HTTP Status Code: 409
- SecurityGroupLimitExceeded
-
Returned if the size of
SecurityGroups
specified in the request is greater than five.HTTP Status Code: 400
- SecurityGroupNotFound
-
Returned if one of the specified security groups doesn't exist in the subnet's virtual private cloud (VPC).
HTTP Status Code: 400
- SubnetNotFound
-
Returned if there is no subnet with ID
SubnetId
provided in the request.HTTP Status Code: 400
- UnsupportedAvailabilityZone
-
Returned if the requested Amazon EFS functionality is not available in the specified Availability Zone.
HTTP Status Code: 400
Examples
Add a mount target to a file system
The following request creates a mount target for a file system. The request
specifies values for only the required FileSystemId
and SubnetId
parameters. The request does not provide the optional IpAddress
and
SecurityGroups
parameters. For IpAddress
, the operation uses
one of the available IP addresses in the specified subnet. And, the operation uses the
default security group associated with the VPC for the
SecurityGroups
.
Sample Request
POST /2015-02-01/mount-targets HTTP/1.1
Host: elasticfilesystem.us-west-2.amazonaws.com
x-amz-date: 20140620T221118Z
Authorization: <...>
Content-Type: application/json
Content-Length: 160
{"SubnetId": "subnet-748c5d03", "FileSystemId": "fs-01234567"}
Sample Response
HTTP/1.1 200 OK
x-amzn-RequestId: 01234567-89ab-cdef-0123-456789abcdef
Content-Type: application/json
Content-Length: 252
{
"MountTargetId": "fsmt-55a4413c",
"NetworkInterfaceId": "eni-01234567",
"FileSystemId": "fs-01234567",
"LifeCycleState": "available",
"SubnetId": "subnet-01234567",
"OwnerId": "231243201240",
"IpAddress": "172.31.22.183"
}
Add a mount target to a file system
The following request specifies all the request parameters to create a mount target.
Sample Request
POST /2015-02-01/mount-targets HTTP/1.1
Host: elasticfilesystem.us-west-2.amazonaws.com
x-amz-date: 20140620T221118Z
Authorization: <...>
Content-Type: application/json
Content-Length: 160
{
"FileSystemId":"fs-01234567",
"SubnetId":"subnet-01234567",
"IpAddress":"10.0.2.42",
"SecurityGroups":[
"sg-01234567"
]
}
Sample Response
HTTP/1.1 200 OK
x-amzn-RequestId: 01234567-89ab-cdef-0123-456789abcdef
Content-Type: application/json
Content-Length: 252
{
"OwnerId":"251839141158",
"MountTargetId":"fsmt-9a13661e",
"FileSystemId":"fs-01234567",
"SubnetId":"subnet-fd04ff94",
"LifeCycleState":"available",
"IpAddress":"10.0.2.42",
"NetworkInterfaceId":"eni-1bcb7772"
}
See Also
For more information about using this API in one of the language-specific AWS SDKs, see the following: