Can I use Amazon's EFS filesystem with cPanel?
Our system requirements documentation states the following:
We only develop and test cPanel & WHM on filesystems that support flock. Some network filesystems (for example, NFS) may require additional configuration in order to function properly. However, these configurations are difficult to implement successfully and we do not support them.
The EFS filesystem does not implement locks in the same way that a normal ext3/ext4/xfs filesystems do:
This means that while some things may work in cPanel others may not work.
If you need a reliable experience, you must have a filesystem that implements locks in an equivalent manner to standard filesystems such as ext3/ext4/xfs etc.
cPanel is not able to provide support for troubleshooting issues stemming from using the EFS filesystem