For concurrent I/O, how do SmartCache and Endurant Cache differ?

You are working with a healthcare company that is interested in replacing all the backend storage for their PACS system.
In general, how should the solution be presented to the customer?

Which Isilon job periodically checks disk sectors to ensure they can be read?

Traditional NAS storage architecture deploys simple two-way failover between two controllers in their storage systems, such as highly-available configurations. How is the Isilon architecture different in terms of system resiliency and availability?

A customer plans to deploy N+2:1 protection on a 5-node Isilon cluster. How much capacity will be used to store a 320 KiB file?