12 bay nas memory capacity 24 tb max hard drives 12 hard drive types hdd ssd hard drive mountings screwed fixed position removable drive hard drive location horizontal internal interface sata iii target audience business internal file system ext4 external file systems ext3 ext4 ntfs hfs fat raid levels 0 1 5 6 10 jbod synology hybrid raid networking gigabit 101001000 connections 4x rj 45 4x usb 30 1x expansion port 1x rs 232 positions of