When using NFS as file system, it is required to make sure that the performances are in line with the Bitbucket Server requirements to guarantee good performances.
The Testing disk access speed for a Java application documentation provides the metrics to be used for comparison when using a local filesystem. However, such values will never be achieved when using NFS.
Provide the metrics for the customer to assess the performances of their instances.
Also, if the tool is not the appropriate one because of the specific way Git operates with the filesystem, it should be enhanced to include specific tests to cover this specific behaviour.