What are the benefits of Isilon Scale-Out NAS versus Scale-Up NAS technology?

A.
File-based storage, File system upper limit 20 PB+, quick scalability, and more granular
file protection

B.
Block-based storage, file system upper limit 10 PB, nodes contain all components, and
RAID protection

C.
Block-based storage, file system upper limit 20 PB+, nodes contain all components, and
more granular file protection

D.
File-based storage, file system upper limit 16 TB, quick scalability, and volume level
RAID protection