NAS: What You Need to Know before Buying

(Jeff Carlson) #1

Originally published at:

NAS (network-attached storage) can be a great way to expand your available data storage, but buying a NAS device involves wading into a lot of technicalities. In this article, adapted from his book Take Control of Your Digital Storage, Jeff Carlson breaks down the NAS buying process.

(SteveLinNYC) #2

Several years ago, I purchased a dual-bay QNAP NAS server for the purpose of storing all my media. In retrospect, I bought the cheapest model available and set it up with a simple RAID 0 configuration. It was grossly underpowered and it crashed constantly. Although it always rebooted itself, the Macs on my network lost connectivity every single time. I ended up donating the NAS enclosure, but keeping the WD Red drives and mounting them in drive enclosures. Actually, those two drives are still functioning as backup boot drives, some eight years later.

Since that time I have used a Mac Mini (replaced once) as a media server, first with synchronized external hard drives, then with a 4-bay thunderbolt external drive from OWC. I have a RAID 5 configuration which has been functioning perfectly for the past few years. However, the thunderbolt drive is noisy - way too noisy to use as a media server, so I had to build a ventilated, sound-isolating cabinet for it. Using a Mac Mini as a dedicated server is overkill, but it has some major advantages on an all-Mac network. All of the apps I have on my other Macs work on the Mini, and maintaining separate accounts for separate users is no more difficult than on my other Macs. I can use the same firewall configuration and the same anti-virus software, although with an additional license. With a little work and by hooking it up to my TV, it can be used as a streaming device too.

I think there are advantages and disadvantages to any file server configuration. My early experience definitely soured me on the use of a NAS. Although I see many advantages and although a NAS is a lot more affordable than a dedicated Mac with an external RAID array, there are a lot of drawbacks to be kept in mind. Perhaps the biggest one is that the file system of a NAS is not a Mac file system and setting up multiple user accounts is nothing like it is on a Mac. Both may use Unix file permissions, but the tools available on a NAS are much more rudimentary and fixing things is much more difficult and involved. If you’ve every tried setting up a router using the built-in web interface, particularly if you’ve had to configure limited MAC access and port forwarding, setting up a NAS is even more complicated. Network security is particularly important - an improperly configured NAS may allow hackers another way into your network.

I think anyone considering a NAS should ask themselves some key questions. Do your really need a NAS? Would a cloud-based service work for you? The monthly fees may be steep, but there’s virtually no work involved in setup, reliability is high and access is available from any device, anywhere in the world. Also, how much redundancy do you really need? A RAID 0 or RAID 5 configuration provides automatic data redundancy but at a cost. If the data on your server isn’t changing all that frequently, having two separate, synchronized external drives can be a lot more practical - you just have to make the effort to keep them synchronized using software such as ChronoSync. Also, Backblaze provides unlimited backup, and that includes attached external hard drives of any size, but not a NAS.

The bottom line in my opinion is that if you don’t need separate user accounts or a high degree of network security, then a NAS may well be the most cost-effective way to go. If you have multiple Macs on your network that are always connected, always on and are not overly taxed by CPU-intensive tasks, then there is little point - multiple external hard drives should be more than adequate. If your needs are more complex, however, and you need a lot of on-site storage with multiple user accounts or with a high degree of security, however, then you’re probably better off with a dedicated computer as a server and redundant external storage.

(Curtis Wilcox) #3

There are Thunderbolt 2 10GbE adapters as well as Thunderbolt 3 plus bare PCIe cards you can put in a Thunderbolt chassis. 10GbE is pricy but it is getting cheaper; the Sonnet Solo 10G Thunderbolt 3 is less than $200, almost half the price of the last Thunderbolt adapter I bought (to use it with a Thunderbolt 2 Mac, I think you can unscrew the back panel, disconnect the TB3 cable, and attach a TB2 to TB3 adapter, those adapters are bidirectional). I was looking at small, “cheap” 10GbE switches recently, they’re roughly $500: Netgear XS708Ev2, QNAP QSW-804-4C, Buffalo BS-MP20.

My understanding is LACP (Link Aggregation Control Protocol) requires configuring it not only on the NAS but also on the network switch ports it’s connected to, requiring it be a managed network switch (at work we definitely had to have the ports on the big Cisco switch configured for LACP for our NASes. NAS’s. Naxen?). Few people at home have a managed network switch and they would be another cost.

CPU and RAM are important for RAID5 performance and for actual file serving, not just for running “apps” on a NAS. If a NAS isn’t hitting the limit of gigabit Ethernet serving files, it’s probably because the CPU is underpowered.

It has become fairly common for NAS vendors to not only sell devices with a fixed set of bundled capabilities but also with optional “apps” one can install and they don’t necessarily have to be developed by the vendor. My impression is Synology has the most robust app ecosystem.

RAID 0 provides no internal redundancy, every file is split into chunks spread across each drive. The odds of losing the data stored on a RAID 0 array is multiplied by the number of drives it contains. Read/write speeds are faster for RAID 0 than a single drive but that’s rather pointless in a NAS because even a single magnetic drive is faster than gigabit Ethernet, the network should be the bottleneck.

(SteveLinNYC) #4

Thanks for your comments, and I apologize for an early morning slip - I meant to say RAID 1 and not 0.

There’s no doubt that a NAS is a tempting approach to providing for massive storage for shared data on a network. A preconfigured NAS is definitely the way to go, and with the availability of apps, the NAS can serve as a very effective media server without the need for a dedicated Mac. With PLEX or Kodi installed, your entire media library can be accessed from any DLNA-capable device on your network. If you’re expecting to back up personal data to a NAS, however, or to have multiple accounts, you’ll need to invest a bit more time and effort. Also, if you want to use it to store your iTunes and Photos libraries, keep in mind that although the content can be shared, they can only be managed by only one computer at a time.

Although a NAS is cheaper than having a dedicated Mac, it’s still a four-figure expenditure. It’s not worth it to try to get by on the cheap with an under-powered CPU. Also, redundancy is no substitute for a proper backup. A RAID5 array protects against a single drive failure, but it doesn’t protect against a natural disaster or accidental file deletion. Backblaze provides unlimited backup for attached hard drives, but not for a NAS. For that, you need a B2 account and Backblaze charges by the GB - for storage, uploads and downloads. The 6TB I have in my Thunderbolt drive, currently backed up for free as part of my Backblaze package, would cost an additional $400 annually if stored in a NAS. Over the life of the drive, a dedicated Mac mini would be cheaper.

(Curtis Wilcox) #5

Yep, I agree with pretty much all of that. Note that Backblaze B2, like basically all cloud storage providers, does not charge for data uploads, only storage, downloads, and a small amount for API calls.

BTW, Wasabi is another cloud storage company, they charge slightly less per GB/month than B2 and they don’t charge for uploads, downloads, or API calls.

(B. Jefferson Le Blanc) #6

My needs are somewhat less industrial. When I bought my 27" iMac more than four years ago, all the Thunderbolt solutions were expensive RAIDs. Then OWC came out with the original Thunderbay 4 drive enclosure and my problems were solved. I had a variety of hard drives, two from external cases and two from my old Mac Pro. But a RAID requires matched drives, and mine were various. The Thunderbay 4 supported those mismatched drives just fine. They mount individually on my desktop. Of course I’ve upgraded all the drives in the meantime, but the Thunderbay 4 matches my iMac with the original Thunderbolt 1 standard, which is plenty fast enough for 7200 rpm drives.

I store most of my data on one drive and back it up on another. I also have a Time Machine partition and a clone of my internal drive, and one other drive for various archives. Oh, and I have a bare 5TB drive that I’ve partitioned for additional backup that I started keeping in a safe deposit box a few years ago. I use a Voyager S3 “toaster” to access this and other bare drives.

If you have a newer Mac with TB2 or TB3, OWC has kept up with the times, offering compatible versions of the Thunderbay 4. And, unlike some reports I’ve heard, my Thunderbay 4 is not noisy. I suspect the noise issue has to do with the drives one is using rather than any inherent problem with the enclosure. Oh, and OWC makes models designed for 2.5" drives and SSDs as well.

I have a small local LAN using a simple Ethernet switch over which I can share any of these drives to computers connected either by wire or via WiFi. Screen Sharing also works reasonably well. And my Router uses the switch to provide internet access to all connected computers.

In any case, if you have lots of external drives cluttering up your workspace, a Thunderbay 4 is a good way to consolidate your drives and save space without the complexity of a RAID or a NAS. And it is easily upgraded as well, or rather the drives are.

This may be a bit off topic, but if you are considering a NAS, I think alternatives are relevant. Just as RAID and cloud storage are.