Originally published at: https://tidbits.com/2018/08/27/nas-what-you-need-to-know-before-buying/
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.
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 youâve every tried setting up a router using the built-in web interface, particularly if youâve 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 thereâs 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 isnât 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 donât 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 youâre probably better off with a dedicated computer as a server and redundant external storage.
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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, âcheapâ 10GbE switches recently, theyâre 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 itâs 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. NASâs. 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 âappsâ on a NAS. If a NAS isnât hitting the limit of gigabit Ethernet serving files, itâs 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 âappsâ one can install and they donât 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 thatâs rather pointless in a NAS because even a single magnetic drive is faster than gigabit Ethernet, the network should be the bottleneck.
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Thanks for your comments, and I apologize for an early morning slip - I meant to say RAID 1 and not 0.
Thereâs 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 youâre expecting to back up personal data to a NAS, however, or to have multiple accounts, youâll 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, itâs still a four-figure expenditure. Itâs 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 doesnât 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.
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 donât charge for uploads, downloads, or API calls.
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 Iâve 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 Iâve partitioned for additional backup that I started keeping in a safe deposit box a few years ago. I use a Voyager S3 âtoasterâ 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 Iâve 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.
Old topic but maybe itâs still being monitored. Does the NAS have to be plugged directly into a free ethernet port on the router as most online tutorials show or can it be run through a multi-port ethernet switch (Gigabit or faster)?
Either will work fine. Most of the tutorials talk about plugging to the router as few homes have ethernet switchesâŚ
Cheers,
Dave
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What this article failed to make clear is that RAID is not just used by NASâs but can also be used by DASâs too. So you donât need a NAS to get a big multi-drive volume; you can just as well get a RAID box thatâs a DAS.
What is more interesting and open for debate about the differences, is whether itâs better just to use an always on (low energy usage with M-series) Mac which has decent CPU/GPU with large DAS hanging off it via fast 40Gb Thunderbolt 3/4 (even if you donât saturate the max 40Gb speed), vs. just having a decent 10GbE NAS somewhere on your network?
That question is typically completely avoided in NAS journalistic articles, for some reason.
AFAIUI, most modern Macs will beat almost any NAS for reliability and certainly performance (maybe except for only the most expensive NASâs CPUâs perhaps??), making the Mac+RAID DAS idea both faster for moving data on/off the storage box but also for transcoding duties (using the Mac to do it), and affordable Backblaze-type data backups.
I wish there were better options in the DAS box world.
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My three old Drobo multi-drive boxes were retired this last week. The 5 drive (5D) Thunderbolt 2 power supply had died, the 5N2 NAS was off loaded and the original 8 drive NAS was too slow today and only 18TB of storage. Of course the other main issue is the DROBO drivers will likely die in the next Mac OS upgrade. I replaced them with a Synology 1522+ NAS that has five 12TB drives and all the other Synology options are maxed out so it also has 10Gb ethernet. It has a hot swappable drive capability like the Drobo drives had.
Both my Mac Studio Ultra (10Gb ethernet 128GB Ram and 8TB SSD) and my 2019 Intel i9 Mac mini (10Gb ethernet, 64GB OWC Ram and 2TB SSD) are connected via an 8 port 10Gb switch to the DS1522+.
The Mini has a 4 bay OWC USB C enclosure with four 8TB drives inside attached as a SoftRaid 5 drive. We updated to the new Netgear ORBI 6E wifi system so we ran a 2.5Gb line from itâs router to the 10Gb ethernet switch.
We use Appleâs iCloud to back up all of the iDevices (iPhones. iWatches, big and small iPads). We have six laptops with years of photos that are being moved to the two disk arrays. Takes lots of time even with 10Gb ethernet as the drives through put is the throttle to the process.
NAS is slow but the OWC drive is speed limited as well by the hard drives data transfer speed.
Finally getting backups working like I wanted to do years ago and this is a much more user friendly system for me at age 78.
Carbon Copy Cloner does the backups for me.
Just keep in mind 40 Gbps is the theoretical peak on paper. For data transfer, thereâs actually only 32 Gbps left. And for real-world storage i/o that translates to about max 28 Gbps read and 21 Gbps write. While thatâs still a factor >2 over 10GbE, itâs also about a factor 2 lower than the frequently tossed around â40 Gbpsâ.
And obviously, thatâs total b/w so if you dangle anything else off that TB port (eg. external display) that will further reduce. If youâre out to get max throughout to DAS, probably raiding across multiple separate TB-attached NVMe flashes (which each have to be on their own TB bus, not just port) would be the way to go.
For those who are moderately technical, itâs straightforward to build your own NAS with much greater CPU power (say for Dockers and VMs). unRAID and TrueNAS both work well and have great community support, and support multiple levels of redundancy, so you can withstand more than 1 disk loss if you have a hardware failure.
These are definitely not quite plug-and-play like commercial solutions are supposed to be, but I wouldnât say they are tremendously difficult, either. I do think they are worth considering if youâre interested in either NAS or DAS.
Kevin
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I was really talking about âyour average userâ who doesnât want to build their own custom-build stuff at all anymore, but just buy off-the-shelf stuff, plug-in and use â much like a typical Mac user who wants to get stuff done, rather than having to manage technical stuff in order to do so.
The trouble Iâve noticed is the myriads of NAS raid boxes that are offered in many models from many companies, whereas there just arenât many Thunderbolt DAS raid boxes of any type in comparison.
For HDDâs, the OWC Thunderbayâs seems to be the only multi-bay ones that are reasonably affordable, that you can buy your own drives for to save money. But the fans OWC use are truly atrocious so you get a lot of fan noise (on top of the HDD noise inside)! And as they use software raid, there have been reliability issues with using their SoftRaid for people who need more than R0 or R1 that Appleâs Raid offers, especially using 4+ bay boxes where R5/R6 is more typical.
The only other options for are hardware raid Thunderbolt boxes: LaCie (Seagateâs brand), SanDisk/G-Tech (WDâs brand), and Pegasus â all of which are pre-populated with HDDs, and typically the >2-drive models cost a lot of money per-TByte accordingly.
For SSDs, NVMeâs are the ones to aim for as they offer greater speeds yet are starting to cost similar money to larger volume but much slower SATA SSDs. There are no decent quality empty enclosure Thunderbolt 3/4 multidrive (>2) NVMe raid boxes all all (in order to achieve a single large raid volume, rather than extra speed).
Again, the only ones seen are two 4-bayâs from OWC: Express 4M2 (super-loud fans!) and Thunderblade (only comes with drives and expensive â though some users on MacRumors have resorted to emptying a lower-volume Thunderblade, adding 4 x 8TB NVMe sticks, and re-adding thermal paste as itâs passively cooled â in order to get a QUIET+LARGE VOLUME of decent enough speed NVMe solution! Not exactly off-the-shelf though, is it!)
So not much out there right now.
âŚJellyfin 100GbE for a $gazillion, anyone? 
N=1 case but weâve been using RAID 5 on Thunderbays with Softraid for over a decade without a single RAID issue. Theyâve been solid as a rock. Naturally in that time weâve had a few disk failures but we swap the disk out, it rebuilds and donât have so much as a hiccup.
Our Synology cluster has been pretty good but weâve had one instance where it corrupted itself so badly we completely lost one side of the cluster.
Yup, need more DAS options, but ultimately the problem is macOS: no RAID 6, so even if you could economise on drive and enclosure and avoid proprietary hardware RAID crap (Mac audience, all in-band managed, with bloatware to match) you canât have the reliability of even a custom-built NAS box. So either pay through the nose for the moderate capacity or else do what I did, settle for bus-powered NVME enclosures and use application-level redundancy (read: Time Machine, Arq). Even running Linux on the old Mac Minis isnât an option because external DAS boxes really are confined to the same Mac-centric audience. Ultimately lots of people will (correctly but sadly) conclude that just buying a NAS is simply the better option, even though itâs clearly inferior from both a performance and flexibility standpoint than running your NAS on a Mac with external storage. But there we are.
For affordable products targeting the desktop/consumer space, you mean.
In the enterprise/server space, you can get servers with U.2 and U.3 slots. These drives physically resemble 2.5" SATA drives, but they carry PCIe data on the connectors, making them functionally equivalent to NVMe.
But these drives are expensive, and Iâve only seen the connector used on rack-mount server chassis. So theyâre really only going to be practical if you want to spend tens of thousands of dollars on an enterprise or data center class storage server.
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Yep consumer/prosumer space. Clearly those U.2/U.3 things are more for serious âtypically businessâ users with the cash to match.
Anyway, I wonder if weâll finally see some more 4-drive NVMe box options over the next few months? Otherwise Iâm likely to wait a bit longer then go the OWC Thunderblade manual upgrade route previously mentioned above. I need a quiet(!), fairly large volume box for my media storage.
Also perhaps 8TB-sized NVMeâs will have lowered a bit further to make them feasible in whatever box I end-up using (in 8TB size, âCorsair MP600 Pro NHâ are the most affordable right now, AFAICT, and theyâre decent TLC â rather than QLC, which to my understanding, heavily slow-down after they fill their cache).
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