Date: May 4, 2016
Author(s): Jamie Fletcher
Network Attached Storage is something that all of us want at some point, and Synology has be providing many options for it over the years. Under review today is the DS216+, one of the first generation NAS units to feature Btrfs and Snapshot support with 4K video Transcoding. We take a look at media support, some of the business features, and what’s new with DSM 6.0.
Synology is a world leader in network storage, covering a broad range of products; from consumer focused and budget friendly storage units to save backups and important documents, to full-blown multi-rack enterprise storage arrays filled with dozens of hard drives. Today we will be focusing on the former, with a massively feature-rich prosumer and SMB targeted, but budget friendly 2-bay NAS – the DS216+.
While Synology has been preparing its usual annual refresh of product lines to bring them up to date with the latest hardware, it’s also been updating the operating system that runs on the NASes as well, with a major release update bringing DiskStation Manager to version 6 (DSM 6.0). As such, the DS216+ is one of the first generation NASes to be built for the new OS, bringing with it a wealth of new features.
Since there is so much to cover, we’ve opted to split this review up into two parts. Today we’ll be concentrating on the hardware itself, benchmarks, and a focus on the DS216+ specific features. In another part, we’ll be covering DSM 6.0 in more detail, as well as its effect on other NASes.
Being a plus (+) series NAS, the DS216+ is host to an x86 processor, which allows it access to the broadest range of features and plugins available on Synology’s NAS units. More specific, it’s an Intel Celeron N3050, dual core, 64-bit CPU running at 1.6-2.16 GHz. The first thing to take away from this, is that it’s not an Atom CPU, but rather a much more meatier Celeron, based on the Braswell SoC platform. While compared to something like a desktop CPU, it’s rather underpowered, but dedicated to a NAS, it’s extremely powerful.
Due to this excess of processing overhead and the integration of hardware acceleration, it allows the DS216+ to transcode 4K video down to 1080p for streaming to mobile devices with the included app and plugin. There are some limitations to this setup of course, but be aware that anything 4K related requires a hefty bit of processing power to handle.
The bigger brother to the DS216+ is the DS716+ that recently came out as well; this includes a quad-core version of the CPU, 2GB of RAM, and dual NICs (with the ability to hook up to a dedicated expansion system, allowing for an extra 5 bays). Apart from the that, the two NASes are very similar, but with over a $100 price difference. They are both still 2-bay NASes, and both can handle 4K video transcoding.
The DS216+ isn’t strictly a business NAS (although targeted as an SMB NAS), so it lacks things like dual-NIC plus failover, has no dedicated expansion units (although it does allow external USB storage), and only has 1GB of RAM to run all available services (more than sufficient for most consumer needs). Since it is x86 based, it can run a number of third-party apps like Plex, but be aware that some hardware features may not be available (the hardware transcoder for example).
The two front-loaded toolless bays are where you will load up your available storage, which can be configured for either redundancy with RAID 1, or maximum storage with RAID 0 and JBOD (just a bunch of disks). These arrays can be further configured to be either EXT4, or the brand new Btrfs file systems, which we’ll get into a little later. Up to 8TB hard drives can be used, for a total of 16TB of storage in a non-redundant array.
On the front is a single USB 3.0 port for high-speed file transfers for connected external hard drives. This can be configured to automatically backup external storage to the NAS (and vice versa), when external storage is connected, or manually by pressing the Copy button on the front. Around the back are 2 USB 2.0 ports, for Wi-Fi connectivity, printers and other storage options, an eSATA port for additional external storage, and a single gigabit Ethernet port. There is also a single 90mm fan to help keep the unit cool.
Total power consumption with 2 hard drives at full pelt is a rather impressive 18 Watts (more for less efficient hard drives), and just 7.5 Watts idle, which is even lower than the DS715. For an x86 based NAS, these are some seriously impressive power figures. While it comes with a 60 Watt power supply, this is to give you some breathing room, as well as provide extra power for USB devices (like a USB 3.0 HDD without external power).
Long are the days of a NAS being a simple storage box that’s available on a network. The shear wealth of features available on much of Synology’s NAS range is simply staggering, and almost impossible to cover with any depth. For the most part, we’ll be concentrating on what we would deem some of the more common and applicable features that users are likely to need and test out themselves, as well as the performance impact on a lot of them.
The DS216+ was originally released with the DiskStation Manager (DSM) 5.2 operating system, where the Btrfs file system format was initially made available. Since release, DSM 6.0 came out of beta and went mainstream. It’s this new OS version we used with the DS216+, and as such, a number of new features became available. The new OS makes little difference to performance numbers, and is predominantly a feature upgrade for most of Synology’s NASes.
Some of the features, like the inclusion of automated Let’s Encrypt certificates, might not mean much to most people, but it helps simplify certificate management, and also happens to be free. MailPlus lets you setup your own cloud-based email server on your NAS. Various document platforms like SpreadSheet means you can keep your documents off Google’s services, while keeping them accessible for everyone on the network. You can setup Virtual and Docker DSM environments, allowing for the DSM environment to be setup then moved to another NAS later, or run on multiple NASes for performance. For a small 2-bay NAS like the DS216+, this isn’t much, but if you decide to upgrade the NAS to a larger unit in the future, you could move the entire environment over, without having to reconfigure all the user accounts, permissions and files.
If those kinds of enterprise features aren’t so useful to you, there are a couple of things that will be, even for the average home user. The first is something that many NAS units now include, and that’s personal clouds. Effectively, you can store files on the NAS and make them accessible over the Internet for either other PCs or mobile devices. You get to keep full control over your data, put whatever security you want on, and you only have to contend with your ISP for reliability. Beyond these cloud services, and something new to Synology’s high-end NAS units like the DS216+ and DS716+, is the inclusions of Btrfs, and the associated benefits that come with it.
There are a couple of ways to pronounce Btrfs; butter-fs, better-fs, or my personal preference b-tree-fs. It’s a next-generation file-system built from the ground up, with similar features to ZFS. It’s not just about storing data in ever larger formats, with volume sizes greater than the sum-total of all the hard drives on the planet, but integrating additional features that often required an additional software layer to use. While largely beyond the scope of this article, the inclusion of Btrfs on a NAS is big news, and it brings with it a couple very important features that are critical to backups and data integrity.
The first thing worth mentioning is that there is pretty much no reason not to use Btrfs. The only time you may want to hold off on its use is if you plan to move your DSM environment, either virtual or docker, to a new NAS that does not support Btrfs. In terms of its features, it brings about two helpful abilities. The first is data integrity checksums. When data is written to the hard drives, it writes with it a parity check and two copies of the meta data; when read and the meta doesn’t match up, it will report the error.
This is meant to protect against something on hard drives called “bit-rot”, where single bits of data flip and become corrupt, but otherwise go unnoticed by the hard drive (since the data was read successfully, even though it’s incorrect). Be aware, this does not rebuild the file or data-block (you still need RAID for that), nor will it protect against power outage or software-induced corruption. When used in a RAID array with redundancy, that extra check will cause the array to rebuild that block if there is corruption (as flagged by the checksum).
The next big feature is snapshots. If you have ever used backup software with something called incremental backups, then you will likely be comfortable around snapshots. In essence, snapshots work as an instant rollback for files and folders. If you make a mistake, save a file over an existing one, or accidentally delete something you shouldn’t, you can roll back to a previous snapshot of that file or folder. Multiple snapshots can be saved of a particular folder (up to 256 per folder), and these can be created manually or on a timer (day, hour, minute, etc). Snapshots only save the changes, and do not duplicate all the data. If you have a folder of several hundred files, and you only change one or two of them, only those files will be saved in the snapshot (with a time-stamp).
We should note that, in order to use snapshots, you need to install the relevant plugin called Snapshot Replication. This allows you create snapshots of shared folders on a schedule, and optionally replicate them to either another volume or compatible NAS (the destination needs to support Btrfs as well). Shared folders can also have snapshots visible to users, so that they can undo any mistakes themselves without an admin. These are even visible on the client OS, such as Windows, and will be visible as an advanced folder.
As mentioned earlier in the review, the DS216+, much like the DS716+, has hardware support for 4K video transcoding down to 1080p. There are a couple of limitations with this that need to be mentioned, and the big one is that it’s limited to H.264 compatible formats only. The newer codec, H.265 can not be transcoded in hardware with these particular NASes, but instead relies on the software transcoder. For hardware acceleration of H.265, you will need to get the DS216play.
There are three main media servers for Synology, Media Server is Synology’s DLNA compatible network media broadcaster, and works as a simple interface for other applications to link to for direct streaming. Video Station works as the media server on the NAS, and is Synology’s equivalent of Kodi or Plex, allowing for not just streaming, but indexing and as a transcoder for mobile devices that can not support full resolution files. Plex is a third-party home theatre and media server that’s very popular, and can be installed manually from its website.
If you already have some investment into the Plex platform, it’s worth sticking with it if you can, as it provides a broad range of connectivity options for TVs, mobiles, tablets and media sticks like Roku and Chromecast. The main difference between Synology’s Video Station and Plex comes down to the transcoder – at this time, Plex can not access the hardware transcoder on the DS216+, and fully relies on the software decoder of the CPU (at least through our testing).
To test this out, we uploaded a 4K H.264 video to the NAS and then streamed it from a tablet, in this case a 2nd Gen Nexus 7. You need to download DS Video first in order to access the NAS and use the transcoder (however, if the device can support the format natively, this is not required). DS Video can link to any other media player on the tablet, and Synology even recommends people use MX player, as it allows for a broad range of video formats and additional hardware acceleration on the device.
When playing back the 4K video through DS Video on the tablet, there is a slight delay as it caches, but otherwise works flawlessly. MX player helped keep things smooth with additional acceleration on the tablet. Checking the NAS resource manager, we saw that only 20-30% of the CPU was used for transcoding the 4K video. Image quality was obviously inferior, with noticeable banding in gradients, and fast motion sometimes cause macro-blocking in areas, but otherwise perfectly acceptable on a 7-inch screen.
We tried an H.265 based video, but this would stutter frequently as neither the tablet nor the NAS could decode or transcode fast enough with just software. We switched over to Plex for the next test, with both Plex as the server on the NAS and the Plex player on the tablet. It was not too surprising, but 4K videos was a definitive no-go. The resource manager was pegged at 98-100% and only a second or two would play, with the player reporting the CPU wasn’t powerful enough. Users may have better luck with the quad-core DS716+, but this is unlikely – 4K requires some serious horsepower.
Testing a NAS these days has become simpler, but also stagnant. Many of the older tests like NASPT haven’t been updated in a long time and are no long compatible with modern systems, and simple file transfers are largely limited by a single issue, Gigabit Ethernet. More often than not, the hard drives in a NAS are faster than the network they are connected to, and when you add RAID as well, then the Ethernet becomes the main bottleneck. It’s only really slow disk controllers and overloaded CPUs that are likely to have an issue or slow transfer speeds.
However, we do perform the usual bouts of file copies, and to help with that, we tend to use iSCSI so that we can use hard drive testing applications. In this case, CrystalDiskMark. Because we are dealing with not just two different RAID types, but also two different file system, we thought we’d check to see if Btrfs makes a difference to performance (spoiler: it doesn’t). For testing, we used two 4TB WD Red hard drives, the kind suitable for a NAS. For your own drives, any of the WD Red or Gold series will do, otherwise Seagate NAS range is just as suitable.
|Synology DS216+ CrystalDiskMark|
|RAID 1||RAID 0||RAID 1||RAID 0|
|RND 4KB Q32||16||9||16||9||15||13||16||12|
|Results in MB/s – higher is better|
Don’t read too much into the 4KB results, as it’s likely there is some caching going on, causing the write speeds to be slightly higher. The differences between RAID 1 and 0 are pretty much nil, and as far as Btrfs and EXT4, the difference is so small, it’s barely worth mentioning (slightly better 4KB results in favor of EXT4). In all likelihood, we would need to use SSDs to see any major difference (defeating the point of a NAS), and over dual or quad gigabit with link aggregation. Needless to say, it makes no difference with hard drives whether you use RAID 1 or 0 with either Btrfs or EXT4.
When compared to other NASes, the results are pretty much maxed-out for a single NIC solution. The HDD will limit small file performance due to high access times, and the network interface will limit the total bandwidth available. A standard HDD will normally transfer around 150-175MB/s at peak, and a 1Gbps Ethernet connection equates to about 125MB/s; when you factor in overhead, 110-120MB/s is all you will ever get. The DS216+ is slightly faster than the previously reviewed DS715 in sequential, and it’s slower in some of the 4KB tests, but we’re talking about 1-2MB/s at most across all results.
Raw file performance is only half of what makes a decent NAS, the rest of it is down to the features. Btrfs plus snapshots, the inclusion of some business features like certificate management through Let’s Encrypt, LDAP support, setting up your own DHCP server, the various web server plugins for either websites power by common CMSes, GIT, SVN, access and user privileges, Docker support… It just goes on and on.
For $300, Synology’s DS216+ is very good value for money when you factor in all the extra features, and it’s worth paying the extra $30 over the ARM-based DS216. However, if you are in need of H.265 transcoding, your only option is the DS216play. The much more expensive $450 DS716+ certainly has a lot more processing power, plus the optional expansion bay, but for core features, it might not be worth it. If you are looking for a good all-round 2-bay NAS, the DS216+ is very hard to beat, and as such, thoroughly recommended.
Synology DiskStation DS216+
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