Unfortunately, only almost perfect. Not purchased from Amazon. The NAS works well, the device requires a little training if you are new. The default Synology Raid is not a normal RAID 1, should first be explained. But: Obviously, not only with me breaking the USB together 3 transmission from an external hard drive after a few Gb and puts the whole system paralyzed, there's only pull the plug and restart. USB 2 - much slower - goes. Thus, the use of USB 3 is actually not possible, for. B for backup. Problem apparently known for some time and not fixed.