4 bay nas max hard drives 4 hard drive form factors 25 35 inch hard drive types hdd ssd hard drive mounting removable drive hard drive access front hard drive location vertical internal interface sata iii target audience small and medium sized businesses smbs internal file system ext4 external file systems ext3 ext4 ntfs fat32 hfs raid levels 0 1 5 6 10 5hot spare jbod single disk networking gigabit 101001000 connections 4x rj 45 4x us