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 an EFS file system using One Zone storage
classes. You must create that mount target in the same Availability Zone in which the file
system is located. Use the
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:
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 EC2
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
is the mount target ID, and
requesterManaged property of the network interface to
true, and the
requesterId value to
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 the
IpAddress field to its address. If network
interface creation fails, the entire
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
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. In addition, by always using a mount target local to the instance's Availability Zone, you eliminate a partial failure scenario. If the Availability Zone in which your mount target is created goes down, then you can't access your file system through that mount target.
This operation requires permissions for the following action on the file system:
This operation also requires permissions for the following Amazon EC2 actions: