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Choosing a Synology NAS

I have always been the type of person who built and ran their own file server. I have gone through at least four of them in my lifetime and even wrote an article about how to configure one. But as I got older and time became more precious, I began to hate all of the maintenance those servers required.

Over the last few years I have seen nothing but widespread acclaim for proprietary network-attached storage (NAS) devices. They greatly reduce the burden of maintenance and also provide a lot of interesting functionality that would be a pain in the ass to configure on your own file server. The most favourable brand seemed to be Synology so I finally decided to take the plunge and purchase one. That turned out to be the simplest decision I would have to make.

Synology's product line is absolutely massive. I opened up their website and was immediately overwhelmed with options. I figured that writing down my experience would not only help me make the best decisions but hopefully help others who experienced my same helplessness.

So without further adieu, let's step through all of the decisions I had to make before purchasing my first Synology NAS.

Step 0. Understanding Synology's naming convention

Before you can pick a Synology NAS you must be able to break down their model names. At first glance they appear almost nonsensical. Maybe you can discern what the first two letters indicate, but the numbers and accompanying symbols or random words are anything but clear.

Every Synology NAS follows the same naming convention:

But I'm not even sure that explanation is clear enough so let's break down some examples.

Now that we can break Synology model names down into their component pieces, we need to come up with our answer for each piece.

Step 1. Choose the form factor

This is going to be the easiest decision you have to make because the answer is "DS". For 99.99% of the people reading this, you are going to want a desktop NAS that can be put on a shelf or stuffed in a closet. Unless you know what the words "rack mount" mean there is no way you are going to want anything other than the desktop form factor. And even if you do know what those words mean then you probably don't care what is written here because you most likely know more than I do.

Step 2. Choose the number of drive bays

Wait a moment? Why are we talking about drive bays instead of hard drives? Isn't that the next component in Synology's naming convention? It is but unfortunately the maximum number of hard drives supported does not always equal the number of drive bays your NAS will have. Drive bays are the physical openings in the NAS where you can insert hard drives. How many drive bays your NAS has is probably the most important decision you will make because it determines how much data your NAS can store before expansion.

Let's look at an example to try to make things a bit clearer. The DS1821+ name indicates that it supports up to 18 hard drives but if you look the DS1821+ product page you'll see there are only 8 drive bays. How can it support 18 hard drives then? Because two DX517 expansion units can be connected to it, each of which have 5 drive bays themselves.

The prevailing sentiment from all the reading I've done and the YouTube videos I've watched is that you should not rely on expansion. You connect your NAS to an expansion unit with a single cable which is a large point of failure. Something could very easily go wrong with this cable and it could end up corrupting your data. All of the advice I have seen always says to overestimate the number of drive bays you think you'll need so you can more easily expand your storage in the future.

Desktop form factor NAS come in 1, 2, 4, 5, 6, 8, and 12 bay options. If you are reading this article there is no way you will want to get 1 or 2 drive bays. It will leave you with no room for expansion and barely let you take advantage of the benefits of a Synology NAS. Conversely, a 12 bay is probably way outside even the expansion plans of the people reading this. That leaves us with the sweet spot of 4 to 8 drive bays.

Before you can choose your number of drive bays there is one crucial benefit of a NAS that you must understand and may possibly never have heard of. That is the concept of a RAID. Explaining a RAID in words is nigh impossible so if you'd like to learn more I highly recommend this video by NASCompares.

The most reductive way to describe a RAID would be that it allows you to combine multiple hard drives into a bigger one that provides protection for your data if one of those hard drives fails. If you are purchasing a NAS you are going to want to use a RAID because protection of your data should be paramount. You don't want to wake up one morning and find out that one of your hard drives failed and now you've lost all the photos of your child's first year.

So let's assume we are going to use a Synology Hybrid Raid (SHR) and we're looking at that sweet spot of 4 to 8 drive bays. How much storage could our NAS potentially have? We can finally make use of Synology's RAID calculator tool to help us visualize this.

It is at this point in time that I cannot really make any concrete suggestions because this is an entirely subjective decision based on how much storage you think you'll need and how many hard drives you're comfortable purchasing. All I can do is give you two pieces of advice that I think will help.

  1. Take your estimate of how much storage you think you'll need and increase it by at least 50%. If you think you need 10TB of storage I would say plan for 20TB. If you're estimating 40TB, prepare for 60TB.
  2. Buy larger hard drives and leave drive bays open rather than fill all your drive bays with smaller hard drives. This may seem obvious but some people would rather buy four 4TB hard drives rather than two 8TB ones for their 4 bay NAS. But then a few years down the road they realize they are running out of space.

I decided to go with an 8 bay NAS and 10TB hard drives. This will allow me to get a lot of storage with just four hard drives but leave me plenty of room for expansion.

Step 3. Choose the model year

Choosing the model year for a Synology NAS is almost identical to choosing the model year for a car. Sure you can get the latest year which is going to have all the bells and whistles but you're gonna pay a premium. Or you can get the same model from two years ago that maybe doesn't have everything but it'll suit you just fine.

Synology typically upgrades their models every two years so a DS1819+ is really only one release behind the DS1821+. Synology also provides full technical support for longer than you'd think. Their product support status page has 2015 model year products that still have full technical support.

Your best bet is to start with the latest model year for the number of drive bays you want and work backwards from there. If you want to save a bit of money maybe consider looking at an earlier model. But you may find those newest bells and whistles are worth it and then you can either decrease your number of drive bays or the series.

Step 4. Choose the series

Assuming that you are purchasing a desktop form factor NAS there are essentially four types of series you will encounter which I will list here from best to "worst":

  1. XS+/XS
  2. Plus
  3. Value
  4. J

The simplest breakdown of these series I can give is that the top two (XS+/XS and Plus) are for enthusiasts or those approaching small business use cases. The bottom two (Value and J) are more for people who have little knowledge into this sort of thing and just want to have some extra storage space on their network.

A very important point I want to make is that being low on this list does not mean bad. It simply means the capabilities are less than the series above them. Going back to the car analogy, the J series would be no different than buying a baseline Toyota Corolla. Sure it's not the coolest looking car and doesn't have flashy gimmicks inside but it is a car that will get you from point A to point B.

The number of drive bays spans the entire game of series. You can find Plus models with only 2 bays, J models with 4, and Value models with 8. That is why I said that picking the number of drive bays is going to be the most important decision. You can now go to Synology's product list, filter by desktop form factor and your desired number of drive bays and see which series are available to you.

My personal opinion is that everyone should start with the Plus series and if it is two expensive then drop down to Value. The price jump from the Plus to the XS+/XS is quite large and anyone reading this article is probably not going to be doing enough heavy work that they need the extra horsepower. The price gap between Value and J is usually quite small and the expansion capabilities of the Value series will always trump the J series.

What makes the Plus series the sweet spot is that it typically has a fast enough CPU for enthusiasts with a decent amount of RAM that is upgradable. Also, in the later model years the RAM is error correction code (ECC) memory. In a NAS this is very important because it helps reduce the possible errors that could be getting injected into your data.

So let's take my criteria, desktop form factor with 8 drive bays, and plug it into Synology's product list I get three models: DS1817, DS1819+, DS1821+. If we hop on over to Newgg.com we'll see that the DS1817 and DS1819+ are basically the same price and the DS1821+ is about 18% more expensive. So there is absolutely no reason to get the Value series in this case and now I simply have to decide if that 18% increase is worth the features of the latest model year (spoiler alert: it is).

Step 5. Choosing hard drives brand

Buying a NAS without hard drives would be pretty pointless. We already know the size of the hard drives we want so all that is left is to choose the brand. For all of their products Synology publishes compatibility lists but all of the major brands are on there so it doesn't matter that much.

If you're reading this article you probably want the most straight forward answer so here it is, buy Seagate IronWolf hard drives. Oh you don't like Seagate for some arbitrary reason? Buy Western Digital Red Plus hard drives. Do you want to spend more money on features that you'll probably never use but can feel good that you have? Buy Seagate IronWolf Pro or Western Digital Red Pro hard drives.

There. That's it. Simple as that.

Oh wait, let's throw on the tinfoil hat for a moment. Try to buy your hard drives from difference places. Essentially what you're doing is trying to avoid buying a whole batch of faulty hard drives that just happened to go to a single retailer. If you buy your hard drives from multiple retailers (say half from Newegg.com and half from Amazon.com) you'll likely get a bunch of hard drives that were manufactured at different times and maybe even in different factories. Reduces the chance that all of your hard drives will fail at once.

Step 6. Don't upgrade your RAM immediately

This is more of a warning than a mandatory step but don't worry about upgrading the RAM before you turn your NAS on for the first time. It's a better idea to get it up and running in its default state to ensure that there are no defective parts. Once you are sure your NAS is operating fine for a few weeks, then you can easily shut it down and upgrade the RAM. If anything starts behaving poorly you immediately know the culprit.

Also while we are on the topic of RAM, increasing your RAM is the easiest way to increase the performance of your NAS. Upgrading your RAM means your NAS simply has that much more space to store files in fast memory rather than reading from disk. A lot of the new Synology models tout the ability to install M.2 NVMe hard drives as cache drives under the guise that they will make accessing your data faster. In reality those hard drives are actually more likely to fail and harm you data because NVMe drives are usually not built to be written and read to that often. So unless you know what the words Docker or VMS means, don't bother about cache drives.

Step 7. Come up with a plan to back up your NAS

The number one mistake I think people make about NAS is thinking that it backs up your data. This is not true. It protects your data so that if one hard drive fails and you're using the appropriate RAID type you can recover your data. Backup means that if your house burnt to the ground and your NAS was a molten pile of sludge your data is not lost.

The great thing about buying a Synology NAS is that it comes with amazing software that allows you to back it up. Cloud Sync allows you to encrypt as much or as little of your NAS as you want and upload it to Backblaze, Amazon, Dropbox, wherever you'd like.

Step 8: Pull the trigger!

You now know everything you need to buy your Synology NAS so go ahead and pull the trigger.

For myself the perfect NAS seemed to be the DS1821+. It has a fast Ryzen CPU, upgradable ECC RAM, and 8 drive bays. I'm going to start with four 10TB Seagate IronWolf hard drives in a Synology Hybrid Raid and have the ability to add four more hard drives and evolve into SHR2. It seems like the perfect mix of what I need know and what I'll need in a few years.

Hopefully this article proved as useful for you reading as it was for me writing it.


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