Synology DS3611xs/DS3612xs Review

It’s time to take it up a notch!  Readers of my blog, and those that ask me for advice on home lab and small office environments, know that I’m a Synology fan.  My lab has been running off of a DS1010+ for a while now and I also use a DS1511+ for my home media storage.  They have been nothing but rock solid and easy to use.  I couldn’t be happier with them.  What about the larger Synology NAS for small or mid-sized environments?

Synology makes a lot of different models that vary from small two-bay units (my review of the DS212+ here) to large ten-bay rack mount units that can expand up to 34 spindles using expansion units.  The great thing about the Synology NAS are that they all run the same operating system, DSM (DiskStation Manager).  All of the Synology systems that I use are managed the same way, with the same interface, and with the same software featureset.  Deploying, configuring, and using a DS212+ is the same as the large DS3611xs.

Quick Pic Comparing the DS3611xs (top) to a DS1010+ & DS1511+ (bottom shelf)

About the DS3611xs…

Synology sent me a DS3611xs to test.  Now, the 11 in 3611xs means that it’s a model from last year but I can’t see a difference in the specs.  When I asked Synology they said the CPU was bumped in the 2012 model (DS3612xs) but according to the spec sheets they are both dual-core 3.1Ghz Intel processors.  I have noticed in some pictures that the DS3612xs appears to have a passive huge heatsink where as my DS3611xs has a smaller heatsink with a fan.  The DS3612xs shows a maximum RAM configuration of 6GB, but I believe that is a mistake and it is the same as the DS3611xs, which is 8GB.  My guess is that you can only go to 6GB if you leave the factory RAM installed.  They do have stickers that say “Do not remove!”.  In the end they are either identical or real close to it so I’ll just go ahead saying they are the same.

Ximian Monkey Showing the Rear of the Synology DS3611xs

The DS3611xs is the largest desk/non-rack model that Synology currently offers.  It is a 12-bay device.  The specs include:

  • CPU:  Dual-core 3.1GHz Intel ie-2100 w/ 3MB of cache & hyper-threading
  • RAM:  2GB ECC DDR3 standard, upgradable to 8GB
  • Internal capacity:  (12) 2.5″/3.5″ SATA drives
  • Hot swappable drives
  • External capacity:  (2) 12-bay expansion chassis connected via Infiniband
  • Ports:  4 x USB 2.0
  • Network:  4 x 1Gb Ethernet
  • Internal expansion:  10Gb PCIe Card (single or dual port)

Ports on Back of the Synology DS3611xs

The CPU in this is by far faster than the other Synology NAS and it shows.  This was spec’d to take advantage of the many DSM applications and features without bogging down base disk performance.  The upgradable RAM also supports those other features.  You can enable a lot of things and still not be concerned about overall performance.  Total capacity with two expansion chassis is 36 drives.  Using 4TB drives that gives you up to 144TB!  That’s a lot.

Internal View of the Chassis

It’s a Sleeper…

The DS3611xs looks like the big brother to my other 5-bay units.  It’s just big enough to handle a dozen internal drives, but not bigger than it has to be.  It doesn’t stand out, which is good.  It’s also quiet.  Really quiet.  Just like my DS1010/DS1511 DiskStations the noise you hear will come from the drives you install, not the NAS itself.  That’s impressive with that many internal disks and a real desktop CPU.  Right now as I write this I’m sitting about 8 feet away from three NAS units and I don’t hear them.  That’s a great feature for a lab or a small office environment.

Synology DS3611xs Motherboard

Under the Hood

Inside the DS3611xs is built for speed.  The CPU is 3.1GHz Intel i3-2100.  It has two cores, 3MB of cache, and supports hyperthreading.  My other Atom-based Synology units aren’t slow and this is much, much quicker.  It uses DDR3 ECC RAM and comes with 2GB, but you can upgrade that to 8GB yourself.  If you’re like me you instantly want to add RAM and max it out but once you start using Synology NAS you realize they are very efficient and it’s rare to hit a point where you need more RAM.  I did upgrade my other two boxes because it was easy, cheap, and additional RAM means additional file caching.  Given the I/O that these 12-bay units are capable of I suspect many people will go ahead and move up to 8GB.

Also inside the DS3611xs is a PCIe expansion slot…but what for?

10Gb Now…or in the Future

These 12-bay units are capable of supporting 10Gb Ethernet by use of an add-on card.  I like how Synology did this.  10Gb Ethernet adapters are not cheap and many people will never use them so why pay for it?  With the DS3611xs you can add the 10Gb capability at any time later.  The only gotcha is that you need to select an adapter on Synology’s compatibliity list, which is here.  Anything on that list will be supported by drivers already on the system.  As of right now you’re choice is either Intel or Emulex and you can choose the physical connection type (TwinAx or optical).

Installing the 10Gb adapter is simple and a pretty clever.  You just need to first put the small height bracket on your adapter.

Emulex 10Gb Adapter Installed in the DS3611xs

After booting the NAS back up the 10Gb adapter will show up as LAN5 and 6 (if dual-port).  You configure it just like any other interface in the system.  What’s the use case for 10Gb in a NAS like this?  Easy…  There are a lot of media editors out there or those storing other large files that can benefit from 10Gb.  Contrary to a lot of people’s opinion, bandwidth isn’t often the limiter on storage.  It’s normally IOPS.  But there are times when throughput is key and the ability to add optional 10Gb is a big one.  If you don’t need it you don’t have to pay for it and if you do it’s easy to add an off-the-shelf adapter.  Plus, you’re not locked in when you buy the NAS to decide whether you want to pay for it or not.

But Can It Really Use 10Gb?

Yes.  Yes it can.  My test configuration:

  • Emulex OCe11102-FX 10Gb Adapter
  • 4 x 128GB Crucial M4 SSD in a RAID0 set
  • 8 x 1TB 7200 RPM SATA Drives in a RAID10 set

Now, this isn’t how I’d normally configure this system but I’m going for all out speed here so RAID0 all the way!  I wanted to see how realistic the benchmarks that Synology posts here are for this unit.  They loaded all 12 bays with SSDs, but I don’t have that luxury so we’ll see how 4 do….

Client configuration:

  • Windows 2008 Virtual Machine running IOmeter
  • vSphere 5.0U1 on an Intel X3450 CPU w/ 16GB of RAM
  • Emulex OCe11102-FX 10Gb Adapter
  • Virtual Machine’s VMDK files on NFS datastore exported by DS3611xs

The first test is straight throughput using IOmeter against the SSDs.  32KB sequential read I/Os.

Yes, 32KB sequential read I/Os is cheating but the purpose here isn’t to benchmark the SSDs, it’s to show the throughput capable by the NAS.  With just four Crucial M4 SSDs I can generate 635MB/s of traffic.  Take that to eight or twelve or use newer, faster SSDs and you can easily see the need for two 10Gb Ethernet ports.  The bottleneck here isn’t the NAS.

The second test is IOPS, again using IOmeter against the SSDs but 4KB I/Os this time.  35,000 IOPS!  Out of a tabletop NAS device!  Amazing.  Sure, I’m playing with IOMeter to get the most I can but even under normal workloads you’ll be very pleased with the results.  Running my test VMs off the SSDs was fast, very fast and these are commodity consumer SSDs.

Here is the CPU performance during the testing:

When I was really hammering the NAS and testing both SSDs and SATA drives at the same time CPU use was often higher.

I seriously doubt you’d ever be running this NAS that hard for any length of time but it’s nice to see that even under the worst load it still has headroom to operate.  You quickly see why Synology went to a bigger CPU in these boxes.  They do not have dedicated hardware RAID controllers in them so it’s not unexpected to see the CPU hit that hard.  That’s what it’s there for and it’s doing its job just fine.

Power Usage

The amount of power that the NAS uses depends on the hard drives that you install.  At idle with my 4xSSD and 8x1TB SATA it uses 110v, or almost exactly 1 amp.  At full load during testing of both disk types it went up to 141v, or about 1.31 amp.  That’s really good, in my opinion.  Even if you filled it up with 4TB SATA drives the power consumption wouldn’t go up much and you’d have a box using maybe 1.5 amps with 48TB of capacity.  Amazing.  And again, it’s very quiet.  The unit has two very large fans in the back that run at a low RPM so they do not generate much noise.  Anything you hear comes from the drives installed.

VMware vSphere Support

Many of Synology’s NAS offerings are on the VMware vSphere HCL (Hardware Compatibility List) and this one is no exception.  But…the nice thing about Synology is that they all run the same DSM operating system so if your small NAS isn’t on the HCL you shouldn’t worry.  It most likely works just fine, they just didn’t bother with testing it.  All of the Synology devices do both iSCSI and NFS so you can choose which you’d rather use for your vSphere environment.  A nice touch is that with iSCSI you can do either file base, where it puts a binary file on the filesystem created, or binary where you dedicate entire volumes to iSCSI.  You lose a bit of flexibility there but you aren’t putting binary iSCSI on top of a filesystem which should give you better performance.

iSCSI LUN Creation Options

With the recent release of the DSM 4.1 Beta Synology has gone further than any other storage vendor in its market with the addition of VAAI (vStorage APIs for Array Integration) support. These are additional APIs that offload many storage functions from vSphere hosts to the NAS and are usually only found in larger enterprise arrays.

VAAI Support Options

These are available right now when you create a new iSCSI LUN.  Recently I wrote an article showing how well these options work and what sort of performance improvement you can expect.  You can read that here.

Do You need a 12-bay NAS?

No doubt, for many labs and SOHO environments 12-bays is a lot, not even considering the expansion capabilities.  But here is why I’m a fan of this sized NAS.  Storage tiering.  With a 5-bay unit you are pretty much stuck on one type of drive unless you really have low requirements for capacity.  The DS1518+ is a nice middle step giving you 8-bays, but still can be constrained pretty quickly.  The 12-bay DS3611xs is a great size and I’m a fan already of how I have this one configured.  I have four SSDs for performance and either 7200RPM spinning disks for capacity.  This gives you a lot of flexibility.

DSM does not do any automatic tiering, it’s all manual by you.  In my lab I have some high I/O VMs, and others I just want to be fast like vCenter, on the SSDs.  My other VMs live on the SATA drives.  This is also very useful for VDI environments.  You can put the read-only master VM on the SSD and the delta volumes on the SATA drives.  Very flexible and if you do find you need more capacity you can easily add an external expansion chassis.

Flexibility.  If you need more spindles you can add additional expansion bays and go to 36 drives.  Each expansion is another 12 bays and they connect via an Infiniband cable and port.  They are not chained.  Each expansion plugs in to a dedicated port on the back of the DS3611xs.  That way there is no bottleneck between the chassis.

Good & Bad

First, the good.  It’s fast.  It’s no larger than it needs to be.  It’s very quiet.  It’s very power efficient.  Provides great flexibility.  This larger NAS is no different than the smaller variants I’ve been using for a while now.  That’s a good thing.  Installation was easy and I had it up and running in just minutes.  It has great expansion capabilities.  You can add an off-the-shelf 10Gb NIC.  You can add two more external expansion chassis that connect over very fast Infiniband so the interconnect is not a bottleneck at all.

The warranty for this (and many) Synology unit is 3-years, which I find very agreeable.  In other posts I’ve talked about Synology’s community support and how good it is.  They released a fix for OSX Lion’s Time Machine support for older devices that are no longer supported.  They didn’t have to do it.  It was a very nice gesture that helped out many users.  They have a robust online community for self-support and information on modification and installing non-Synology software on the units (no warranty there, obviously).

Price.  I don’t see this as a bad.  Street price for a 12-bay Synology is around $3,500.  To many of us that use the 2, 4, 5, and 8-bay versions in our lab this is a lot and pretty much blows away most people’s lab budget, but I don’t think it’s bad at all and really…this isn’t a box built for a lab.  This is for a small to medium sized office.  It is a 12-bay, hot swap NAS w/ 10Gb capability and a great featureset.  It’s on the VMware vSphere HCL.  The price is a steal for shared storage in a small virtual environment, especially one with such great expansion capability.  The next level up in storage is several times the cost of this unit.  Plus, let’s be honest.  You put some SSDs in this and you can host a lot of VMs on that.  I say small environment, but with a couple SSDs this will run with many larger storage arrays that sold for 6 figures just a couple of years ago.  During testing it wasn’t hard to hit 10K IOPS out of this system with my SSDs, and that’s without playing with benchmarks to put up the big numbers.  For environments that share large files, such as HD video, the 10Gb option is a great addition that you can add any time.

The bad.  Nothing bad about the unit itself.  I’ve been using it for probably 10 weeks without a single problem outside of a bug with jumbo frames that I reported.  My only real complaint is support from Synology…and not that the support is bad.  When I’ve asked questions or hit an odd bug (like the one I just mentioned) they’ve been very responsive.  My problem is that there is no 24/7 support option.  By default the Synology site directs you to a support form to fill out and a tech will get back with you, usually the next day.  If you click on Contact Us there is a support number to call.  I’ve never used the phone support but I’ve heard very good things from others that needed help recovering a volume or solving a problem.  The support is good…but I’d like to see a 24/7 option now that Synology is moving up market with these devices.  For the price of these units I’m not saying this option needs to be free, just offered as an option.  Synology also sells their products through a dealer network and I’ve heard the same request from a couple of those dealers.

Closing Thoughts

The DS3611xs (and DS3612xs) are evolutions of the other Synology NAS devices.  They are bigger, faster, and more powerful but they are still just as easy to manage and offer just as many options and features as the smaller devices.  Synology is moving up in the market with these and the new rack mountable offerings.  In this space they will hit even more competition, but it’s a good market to be in right now.  Virtualization is quickly being adopted by smaller organizations, not just larger enterprise.  A requirement, at least for now and in the future for many cool features, is shared storage and in the past this has been a financial roadblock for many.   That is no longer the case.

Synology, Drobo, Iomega, QNAP, and others are seriously eyeing this market.  Competition is good as it drives innovation.  It’s also good for customers as it drives down price and that’s exactly what we’re seeing in storage these days.  Now a company with 10 or 20 servers can easily afford shared storage and virtualization…and not just bare minimum functionality shared storage either.  That’s where these devices shine.  Not everyone  needs, wants, or can afford an enterprise class EMC or NetApp array.  I’d have no problem recommending this Synology for such an environment and you’ll be seeing me write more about these in those type of deployments.

12 Comments

  1. Excellent review, very informative.
    But why don’t you mention the DS2411+? It’s the cheaper version, costs only half, and still gives you a 12-bay NAS.

  2. I liked the review, and bought the DS3611xs, and put an extra 12 bay 1211 expansion on it, filled with 4Tb drives the space is excellent, and with RAID-6 the performance is better than standard Gigabit. I didn’t get a 10Gbit card, and have found the link aggregation a pain (doesn’t work with CISCO routers).
    The functionality is excellent, minor issues with Windows mountings for Linux boxes (probably permission issues and not the best way to connect to these boxes for Linux workstations), but when mounted as NFS all works well.
    Compared with an old QNAP 4 disk RAID-5 NAS the performance is outstanding.

  3. just wondering if u tested iSCSI with esxi5.0? as this suppose to be supported on vmware but myself and many others have found the device freeze as soon as iscsi i is used,
    NFS work ok in esxi 5.0

    Pat

    • Yes, and have no issues with iSCSI and vSphere 5. All of the VAAI testing in this review and my benchmark post were done using iSCSI.

    • The problem with NFS is you can’t use MPIO to improve performance.

  4. The tests you show are not out of cache. Running tests in cache is pretty meaningless.

    Run Iometer with a 10Gb iobw.tst file and you will get nowhere the IOPs you are showing (more like 3000).

    • I’m very familiar with IOMeter and it’s default setup. This was run using a much larger test file than 10GB. The DS3611xs has 2GB of RAM so it’s not a ton of cache (until I upgrade it). The IOPS I’m seeing are right in line with what I’d expect with these SSDs in a RAID10 configuration.

      • Cheers nashwj, always good to clarify the testing is out of cache, about 8 times what we got with 1TB SATA in a similar tests. Personally I think RAID 10 is overkill with SSDs as the performance (particularly reads) is so good.

  5. John – you need a (cisco) switch, not router. Should work fine with all LACP supported switches, which should be about all manageable switches..

  6. Great review! I think its time to flog my QNAP TS-509 and get the Synology. 10GbE performance seems like where its all at with this device.

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