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Synology

Synology 5bay Expansion Unit DX517 (Diskless) 157 mm x 248 mm x 233 mm

Based on 582 reviews
Condition: New
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$584.91
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Availability: In Stock.
Fulfilled by vCloudTech
Arrives Nov 14 – Nov 16
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At a glance

Condition
New
Model
DX517
Storage
10000 GB
Weight
8.6 lb
Color
Black
Hard Disk Interface
ATA-4
Hard Disk Form Factor
2.5 in
Warranty
3 Years
Works with
Desktop

Features 4

  • Easily add 5 additional drive bays to Synology NAS. Please check Synology website for compatible models
  • Supporting both 2.5" and 3.5" SATA drives
  • Hot-swappable drive tray design
  • Synology DX517 can be used as a dedicated local backup solution for the Synology DiskStation. When created as a separate volume, the DX517 provides a great backup solution to its local hard disks in case of system failure

Description

Synology DX517 offers simple storage capacity expansion solution for your Disk Station through its intuitive plug-n-use design. DX517 allows you to instantly scale up to 5 additional hard drives, so that you can expand RAID volume online or deploy the drives as a dedicated local backup destination for your Disk station. Synology DX517 is backed by Synology's 3-year limited warranty.

Specs 32

Digital Storage Capacity 10000 GB
Hard Disk Interface ATA-4
Connectivity Technology eSATA
Brand Synology
Hard Disk Form Factor 2.5 inches
Hard Disk Description Hybrid Drive
Installation Type Not Specified
Color Black

Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Nov 14 – Nov 16

Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.

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Similar Products

Top Amazon Reviews

Top Value Prosumer/Small Business Storage Solution.
Style: Unit
I've been using data storage products for decades professionally and at home. I used to build my own and eventually almost 10 years ago ended up with Synology. So far Synology has exceeded my (very high) expectations. A product should be judged on several metrics: 1) product - the thing you buy 2) Life cycle - the thing you buy over the period you have it 3) support - can you get support when (not if) you have problems First, Product. Synology DX1517: I added this DX1517 to my DS1517+ at my home office. I'll touch on overall Synology but focus on the DX1517 (this product). Synology storage products are centered around a Linux-based DSM, or Disk Station Manager that runs on their DS (Disk Station) line. For a home/small office environment, it's extremely powerful. DSM has very strong base functionality that is complimented by a long list of applications that you can add from both Synology and 3rd party vendors. Like Apps for your PC or phone, many of those applications are free. But like Microsoft Office with Windows, not all applications are free. One in particular that DSM requires payment for after a certain point is Surveillance Station. You can only run up to 2 cameras for free on Surveillance Station, after that you need to license Surveillance Station per camera (and despite what some incorrect reviews have stated) purchased camera licenses are transferable to other Synologies. I've done it. Further, if you can't find the application you want Synology also offers Docker so that you can add generic 3rd part apps if they are available in Docker containers. I have 10 apps installed that way and start/stop them as necessary. DSM and any installed application can work across any system volumes that DSM is aware of. Adding the DX1517 is simple: be sure everything is powered off, the disks are installed in the expansion unit, the eSata cable is inserted correctly and tightly screwed in on both ends, and then turn everything on. Magic, you have more disks. In DSM, create a new volume on the new expansion disks. It'll then do a consistency check the volume and then you're good to go. Done. So with this, I now have 50TB spread across the main and expansion unit in two volumes each in RAID 6. Yes, out of 10 disks I'm "wasting" 4. Read on. Here is the key: DO NOT SPREAD A VOLUME ACROSS eSATA CONNECTED DEVICES. I run a separate volume on the expansion unit (all, and I mean ALL, storage vendors strongly recommend that setup) so I have 2 volumes, one on the main DS unit, one on the DX unit. DSM doesn't care, and I certainly don't have a database or anything that needs more space than a single volume. Can you have only a single volume spanning devices? Sure you can. You can also drive most cars manufactured today over 100+ mph. But here's the difference: running a volume across an eSATA connection is like you ONLY being able to drive your car over 100mph ALL THE TIME. When (not if, but when) something goes wrong (which might be your own error, might not), the consequences sort of suck. RAID 6 only allows 2 disks redundancy. If I only had a single volume across my DS and DX and anything were to happen to either my DS, my DX, the power cords going to either, or the eSata cable connecting them, I'd lose 5 disks in the volume. So if I had one volume across both devices, that volume would lose 5 disks. 5 disk > 2 disks. RAID 6 isn't going to help much. Good luck. (For the purists, depending on the nature of the failure there is an outside chance that I could be able to re-establish read-only access to the volume if I can get all drives spinning again. But what would I rebuild 50TB onto ???) So TL;DR: the expansion unit just is and just works. It's transparent, and so long as it's installed correctly, I don't even think about it. I just interface with DSM. Second, Product Life-Cycle Synology does an amazing job of keeping DSM and the core Synology Applications not only up to date for security and reliability issues but they actually increase functionality over time as you own your product. They don't just do that for the first year or while the product is under warranty - but so far for the DS+ series about 5 years or more after the product comes to market. This is a huge plus. Many companies put out a decent product then rush to develop another product they can sell and leave the previous products with old, buggy and insecure firmware. After awhile, what had been a decent product initially becomes incompatible, insecure, and effectively unsupportable (many lower-end phone vendors running Android do this - they simply don't offer updates when they're focused on their next product. Synology product life-cycle record has been first rate. Will it continue to be? Who knows, but the best indicator of future success is past success. Thirdly, Product Support. Storage device support is and should be centered around preventing data loss. I have first-hand experience with Synology live support on a DS1511+ I used to have. Superlative support: I had power problems in my house resulting in my DS being forced to restart repeatedly and ending up not being able to boot from disk. Contacted Synology support, within a day a human being actually manually logged into my system, un-messed it up, and I was good to go. Here's the kicker: the DS1511+ was out of warranty at the time, and they were aware of that. I was and still am impressed. Find another < $1,000 product that will do that. Then find one that will do that when the product is out of warranty. This kind of support is only even remotely feasible if the company keeps the products up to date - meaning, if the underlying product life-cycle is solid. Synology delivers here. I have to comment about the guy going all over Amazon screaming that they won't support the hardware product after the warranty period. First, Synology's base warranty is 3 years. Second, Synology offers extended warranties of 2 years if that's what you want, so you can get 5 years warranty. Finally, it's usually preferable and in the long run cheaper to replace a 3+ year old failed device than it is to get it fixed, particularly at these cost points. It depends what goes wrong: fans, PSUs are easily fixed by local talent. More than that, and even for a PC I'd recommend getting a replacement device. The old drives will work with the new device. If you're worried about Synology SHR RAID, just use RAID 6. Then you can go to any Linux-based device. But if you get a replacement Synology, just slot the drives in, boot it up and you'll be good to go. For a storage vendor, I'm happy if they prioritize data loss issues for real support. If I want help setting up Photo Station et al, there is a solid ecosystem in place for getting help both on the Synology web-site (forum, wiki) but also on other locations (reddit, SynoForum, etc). Overall, I still give Synology 5 stars. ... show more
Reviewed in the United States on December 17, 2019 by Joseph Luke
Expanding Storage with Ease and Reliability
Style: Unit
TLDR: As an experienced user of data storage products, I'm impressed with Synology, particularly the DX1517 expansion unit. Its integration with the DS1517+ was seamless, offering robust functionality and reliable RAID 6 setup. The device's ease of setup and DSM's versatility stand out, though I advise against spanning a single volume across connected devices for safety reasons. Having spent decades both professionally and personally dealing with data storage, I've come to appreciate quality products. Synology, which I've been using for almost a decade, has consistently met and exceeded my high expectations. When evaluating a product, I consider three key metrics: the product itself, its lifecycle, and the support available. Focusing on the Synology DX1517, which I added to my DS1517+ at my home office, I'll discuss my experience with it, keeping in mind these criteria. First, the Product: The DX1517 expansion unit was straightforward to integrate with my existing DS1517+. Synology's products are based on the Linux-driven DSM, or Disk Station Manager, which I find to be extremely powerful for home/small office environments. DSM offers robust base functionality, enhanced by a wide range of applications from both Synology and third-party vendors. While many of these apps are free, some, like Surveillance Station, require payment after a certain point. I added the DX1517 easily. It required powering everything off, ensuring the disks were in the expansion unit, and securing the eSata cable. Once powered on, it was a simple process to create a new volume on the expansion disks in DSM. I now have 50TB across the main and expansion units in two separate volumes, each in RAID 6 configuration. It's crucial not to spread a single volume across eSATA-connected devices, as it risks the entire volume if there's an issue with one of the units or the connecting cable. In RAID 6, only two disks redundancy is allowed, so spreading a volume across both devices would risk significant data loss if more than two disks fail. Second, Life Cycle: From my experience, Synology products are durable and reliable over the long term. The DX1517 has proven to be no exception, continuing to function effectively without issues. Third, Support: Synology’s support has been adequate. While I haven't had significant issues requiring their assistance, it's comforting to know that help is available if needed. In conclusion, the Synology DX1517 is an excellent addition for anyone needing expanded storage. It's user-friendly, reliable, and integrates seamlessly with existing Synology systems. My advice to potential users is to be cautious with how you configure your volumes and understand the limitations of your RAID setup. ... show more
Reviewed in the United States on January 19, 2024 by Chicago Ben
Nice way to expand
Style: Unit
I was using one 14TB drive for video storage in my current DS1621xs+ unit and wanted more. I decided I would double my storage, but I wanted to ensure speedy access. The DS unit I had would not let me go from a single drive to a striped array, but it would let me go to a raid 5. I powered down the system and I took the current WD 14TB Purple drive out of my DS, put it in my new DX517 along with two more matching 14TB drives, and powered everything up. My DS unit recognized my old drive and also asked me what I wanted to do with the new drives. I simply selected modify array to raid 5, hit start and waited. I had access to all of the information on my old drive through the entire process, which is very good, because it took a lot of time; going from almost 13TB of full drive data to just over 25TB of capacity took about a day for stage 1, then another day and a half for stage 2; all of my data was intact. After I was all done, I did a speed test to the new array and was very happy with a peak speed of 1.06 GB/s across my network; I run a 10Gb backbone and connections from my PC to the DS unit. This was very expensive, but I am very happy with the performance and ease of this upgrade. I have another, older DS unit and I am planning on adding a DX517 to that unit as well; all of the drive bays are full, and I need more room. I would recommend the DX517 for it ease of use and performance, but the cost is a bit extreme for what is basically a power supply and a E-SATA external housing. ... show more
Reviewed in the United States on January 24, 2023 by David C. Harris
Joining to my DS918+
Style: Unit
Review Image by Rock Edge
Review Image by Rock Edge
Review Image by Rock Edge
Review Image by Rock Edge
Review Image by Rock Edge
Review Image by Rock Edge
Review Image by Rock Edge
I recently installed a DS918+ and have been very impressed with the speed, management tools and Plex performance. Having migrated off an older NAS, I had hard drives laying around, so logically I needed this! The retail packaging with handle came inside a Synology type warehouse box fully taped and that was nested inside a larger Zon box with a ton of paper packing around it. Nicely done there. Set up was easy. The cable is custom for the Synology connectors and only about 18 inches long, so you need to store them alongside or very close to each other. I have them on separate shelves on a wire rack vertically and it reaches fine (hopefully the pic is approved for your review). Similar to my DS918+ review, the unit is very light until you put drives into it, but it's not a cheap feel. This one has distributed lights over each bay. The master NAS has lights running down the side. I may need to hit the forums to see if I can mute or turn those off. The drive trays are spring loaded and only took just a few minutes to mount a couple of disks. When re-inserting the tray into the NAS, be sure to not have the spring loaded cover already pressed, it won’t fit snugly nor mount the drive properly. No danger here just have to click it out and slide it in then lock it in place. Power it up. Once attached to a supported NAS device for management, you go to that units web interface. I didn’t have to take any action, but could see from the dash board on the ‘desktop’ admin tool that it had additional drives available. So I launched Storage Manager right away. On my base NAS I created a straight Raid 5 volume. For this set of disks, I'm testing "Disk Group" running SHR, Synology's proprietary raid solution. The biggest thing you can get out of SHR over a typical raid with single disk protection is you can keep adding hard drives. Since this is 5 bays, I started with 3 4TB drives and the usable space is about 7.4 TB. After I move some data around, I'll add another 4TB and expect right at 11 total... then test adding another drive and will report back here the result. Please note if the drives are of varied sizes, my understanding is that it will round down to the lowest drive size. So 1 4TB and 1 2TB SHR’d would be the same as 2 2TB drives. Plenty of cool YouTube vids to explain better for you. After you create your disk group, you go to the Volume tab and do a “Create” from the menu up top. Next you’ll want to see that storage right away (it’s doing a disk check but the space is usable rather quickly). Launch File Manager and create a new share. Set up the name, security all that and you are ready to rock. I’ve got a lot of juggling to do but will do some speed tests soon. So far Volume to Volume tests seem really fast which is great, but not sure that will be the primary access use case. Check out the DS918+ reviews on the user interface and positives there. Over all I am very pleased with the expansion. ... show more
Reviewed in the United States on October 25, 2017 by Rock Edge
My Experience with the Synology 5-Bay Expansion Unit DX517
Style: Unit
As a digital hoarder, I've always struggled to keep up with my ever-growing data collection. My previous NAS system was starting to reach its limits, and I knew I needed to expand my storage capacity. That's when I discovered the Synology 5-Bay Expansion Unit DX517. Setting up the DX517 was a breeze. I simply connected it to my Synology NAS, and it was immediately recognized and added to my storage pool. The hot-swappable design allowed me to easily add my existing hard drives without having to power down my system. Now that I have the DX517, I can finally store all of my media files, documents, and backups without worrying about running out of space. The increased storage capacity has given me the freedom to download and save whatever I want, without any limitations. If you're looking for a reliable and easy-to-use way to expand your storage capacity, I highly recommend the Synology 5-Bay Expansion Unit DX517. It's a game-changer for anyone who needs to manage large amounts of data. ... show more
Reviewed in the United States on September 21, 2024 by R Washington
Excellent, convenient. Works as a separate NAS. Can use much larger drives. Runs a bit warmer.
Style: Unit
Very simple and convenient way to add a new NAS. Flawless for a year now. Rather than extending the RAID of the main unit, this creates a separate RAID. For instance used for hyper backup, a back up of part of the main unit on a separate unit. It is a new storage unit, a separate RAID array, without the bother of a new CPU, connectors, and so on. The unit runs slightly warmer, 37C vs 31C for the main unit. Same performance. It will slow the machine for a while at the beginning, while every sector is written, read and verified. After wise it zooms fast. The Synology compatibility page for hard drives is not updated. The drive kind matters, but the capacity can be arbitrarily big. I use without problems Western Digital 22TB WD Red Pro while the max capacity listed for these is 10TB. ... show more
Reviewed in the United States on November 29, 2024 by Adrian O
It is an expensive branded SATA enclosure
Style: Unit
As others have said, you are paying a premium for a a single bus eSATA expansion that fits certain Synology NAS boxes. It works well, and the causes no issues with any of the Synology DSM software. That is a huge plus. Everything else is either neutral or a minus. First, you are limited to the bandwidth of a single eSATA bus per expansion box. That means your maximum transfer rate is about 600 megabytes per second period. If you are dealing with small files, or lots of random access, the speed is even slower. If you want to speed things up, you need to add cache drives to the bays of the expansion unit. Synology allows you to share the NVMe cache in the parent NAS, but you risk a RAID crash if you lose your data connection or have a bad shutdown. If you choose to use bays for your cache you are limited to 4 expansion bays and one read only cache or 3 expansion bays and a read / write cache. Once again, you are still limited to the bus speed, but SSD SATA cache drives are faster than traditional drives. You will speed up file transfers by 15%+ with SSD read / write cache. Second, you are paying a fair amount for what is really nothing more than a branded eSATA RAID box. It is nice that out of the box, it works, but it is rather expensive for what it is. Finally, it is nice that the NAS you plug this into controls the expansion just like your NAS. It is really easy to maintain, expand and every other function your RAID. That is the best reason to purchase an expansion versus adding a non-branded eSATA or USB solution to your NAS. Do I recommend this if you need to expand your storage and speed isn't a premium? Yes I do. ... show more
Reviewed in the United States on February 28, 2023 by Amazon Customer
Compatible with the older models (from 2 years ago), not the new ones.
Style: Unit
Just what was needed, works perfectly. Buyers, be careful….check compatibility. Synology intentionally builds in compatibility obsolescence…I know from experience..
Reviewed in the United States on December 27, 2025 by Jerry L. Parker
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