By default, SSH is enabled on storage servers. If required, you can "lock" the storage servers to disable SSH access. You can still perform operations on the cell using ExaCLI, which runs on compute nodes and communicates using https and REST APIs to a web service running on the cell.

When you need to perform operations that require you to log in to the cell, you can temporarily unlock the cell. After the operation is complete, you can relock the cell.

For details, see Disabling SSH on Storage Servers in the Oracle Exadata System Software User's Guide.