Mount settings used by EFS mount helper - Amazon Elastic File System
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Mount settings used by EFS mount helper

The Amazon EFS mount helper client uses the following mount options that are optimized for Amazon EFS:

  • nfsvers=4.1 – used when mounting on EC2 Linux instances

    nfsvers=4.0 – used when mounting on supported EC2 Mac instances running macOS Big Sur, Monterey, and Ventura

  • rsize=1048576 – Sets the maximum number of bytes of data that the NFS client can receive for each network READ request to 1048576, the largest available, to avoid diminished performance.

  • wsize=1048576 – Sets the maximum number of bytes of data that the NFS client can send for each network WRITE request to 1048576, the largest available, to avoid diminished performance.

  • hard – Sets the recovery behavior of the NFS client after an NFS request times out, so that NFS requests are retried indefinitely until the server replies, to ensure data integrity.

  • timeo=600 – Sets the timeout value that the NFS client uses to wait for a response before it retries an NFS request to 600 deciseconds (60 seconds) to avoid diminished performance.

  • retrans=2 – Sets to 2 the number of times the NFS client retries a request before it attempts further recovery action.

  • noresvport – Tells the NFS client to use a new non-privileged Transmission Control Protocol (TCP) source port when a network connection is reestablished. Using the noresvport option helps to ensure that your EFS file system has uninterrupted availability after a reconnection or network recovery event.

  • mountport=2049 – only used when mounting on EC2 Mac instances running macOS Big Sur, Monterey, and Ventura.