You have a 35 x 6TB HDD and 1 x 800GB SSD config on NL400. 800GB SSD disk should be in first slot (front top left) as a L3 cache.  OneFS Caching explained here in EMC Isilon OneFS SmartFlash
hello we have a question about nl400 installation , we have 36 disks 6tb sata  x node nl400 and 1 disk 800 gb sas disk.. our question is why ? there is a particular slot in wich we have to install 800 gb sas disk ?  many thanks regards cester giacomo and massaro emanuele
information aabout nl400 installation with 6tb disks and 800 gb disk sas