The Storage Modules in Catalyst Switch 9300 and 9500 are optional modules that can be added to the switches to provide additional local storage capacity. The purpose of these modules is to allow the switches to store more local data such as logs, configurations, and software images.
Whether or not the Storage Modules are required for normal operations depends on your specific use case and requirements. If you don't have a need for additional local storage capacity, then the Storage Modules may not be necessary for normal operations. However, if you anticipate a need for storing large amounts of data locally, or if you need to maintain logs or configurations on the switch, then the Storage Modules may be useful.
In summary, the Storage Modules in Catalyst Switch 9300 and 9500 are optional and their necessity for normal operations depends on your specific use case and requirements.
