Hi, you might need to reach Support or possibly beyond. If you buy these drives as "upgrade" they will create a new one. 
Hi all, We are trying to reuse some Isilon NL400 with 1,3 and 4TB drives. We want firstly to remove all configs and info in the disk so we are performing a "isi_reformat_node" procedure. We reformat nodes with 4TB drives correctly but with 1TB or 3TB drives we see this error message: newfs_efs: One or more installed drives are too smal for this product Then system restarts and wipe is not performed. Could someone help us to solve this situation?.Is very strange a limitation like this. Regards,    
NL400 unable to use with drives less than 4TB