Synology Nas Dx517 5xhdd 2.5/3.5´´

Package received quickly and superbly packaged. I use the Synolgy DX517 in addition to my Synology DS1621+. Both work perfectly well. Integration is simple, a power supply, an eSata cable and the NAS recognises it. I put the extension on the NAS and it doesn't move. All I have to do is set up the RAID configuration etc... and it's perfect. I am always delighted with Synology products, especially in terms of silence, power consumption and size. Great product.

The Synology DX517 is a very well made disk enclosure, in fact it puts the DS723+ I've attached it to, to shame! The drive trays fit much more tightly and are spring loaded to release. The power supply is integrated into the unit and all the cabling is of high quality. The setup was absolutely seamless when connecting to the DS723+ I did not even need to power down the NAS. I connected all the cabling with the expansion unit powered off. Loaded all the drives and then powered on and it immediately appeared in DSM Storage Manager as a DX517 with all bays populated and I was able to build an array and get started within minutes. It is expensive, but it is well built and it is very good.

Too soon to comment on reliability. Build quality, ease of installation both excellent. Pricey for what is essentially a port extender in a box but works beautifully with a 2 year old DS1819+

Does not accept all disks (there are mechanical deceptions), so it is advisable to take disks for NAS. Connects with a cable (included) that screws to the NAS for e-sata. The NAS can put it to sleep/shutdown/restart so the start button will not be used often. Quiet fans. Beware, the chargers are not the same as on the DS920, but it's still a 3 1/2 drive assembly without screws: happiness.

Added to a ds920+, not quite the same shape, and non-interchangeable drive slots, LEDs not in the same place (on each drive) but once connected and the 920+ rebooted (and yes, you have to reboot) is instantly recognised. Offers 5 additional bays, which allow you to create a volume and add a hot plug disk for the existing volume or the new one, allows to extend the old one, etc... In short, essential if you hope to grow in volume, rather than change all your disks. And allows you to take advantage of SSD caches just in case.