SFD7: Exablox - Scale-Out Object Storage for NAS

Exablox is one of those companies I’ve followed for some time and it was great to see them presenting at Storage Field Day 7 earlier this year. The company sells a scale-out NAS platform, supporting the CIFS, SMB and NFS protocols, making it a perfect file server environment for small and medium enterprises.

Technology View

The interesting difference in approach that Exablox has taken compared to other vendors in the market is in both the hardware and software design of their solution. There are two main products; OneBlox 3308 appliance and the 4312 appliance. Within the naming, the last two digits appear to apply to the number of drives supported in each appliance while the first digit is a generation number.

3308 Appliance – this is a 2U form factor rack mount unit that is only 15″ deep and has a small LCD screen on the front. At the back, the unit simply has four Ethernet (GbE) connections, a USB port and a power supply. The LCD screen can be lifted to reveal eight 3.5″ drive slots, supporting both SAS and SATA drives at a maximum capacity of 6TB each (48TB total). Protocol support is SMB (1.0, 2.0, 2.1, 3.0) and NFSv3.
4312 Appliance – this model is still 2U in height but looks more like a traditional rack-mounted server and is approximately 700mm deep. Connectivity is uprated to 2x 10GbE and 2x 1GbE with an additional optional 2x 10GbE ports. Power supply is redundant and the unit is capable of supporting up to twelve 3.5″ drives at a maximum capacity of 8TB each (96TB total). Protocol support is SMB (1.0, 2.0. 2.1, 3.0) and NFSv3.

From a hardware perspective, everything looks pretty simple, however looks can be deceiving. The 3308 appliances are remarkably quiet, consuming a typical 150W and capable of being deployed in an office environment on open rack shelves. The images in this post were taken in Exablox’ lab that contains dozens of test appliances and still allows for normal conversations. Unlike most NAS vendors, Exablox sell their appliances without drives, so customers can choose what drives to deploy into the hardware. This makes the cost of deployment of an Exablox solution (potentially) significantly lower than the competition, as there is usually a big markup on raw drive cost added by most NAS solution providers.

The remainder of the innovations come in software, both at the data layer and within the management tools. OneBlox systems use a ring-based distributed object store with erasure coding, onto which the company has laid their own file system. A single ring can scale up to ~~six~~ seven appliances and 672TB. The object store uses multiple size objects and algorithms that enable the system to manage multiple drive sizes within a single chassis or across multiple OneBlox appliances. Data efficiency is achieved through the use of inline de-duplication technology and all data on physical disk is encrypted.

The use of an object store at the back end provides the ability to deliver a feature known as continuous or CDP snapshots. Objects stored in object stores are typically immutable, meaning they don’t get updated in place. Instead a new object is created and the old one either deleted or retained for versioning. Exablox’s use of an object store underneath the file system means any updates to a file (which will comprise multiple objects) can be tracked and used to deliver highly granular snapshots. The trade-off comes from balancing the snapshot granularity against the additional storage overhead.

OneBlox systems are managed using a web-based interface that runs off-board from the appliances in a “cloud-based” deployment known as OneSystem. At first glance it may seem a little strange that an on-premises appliance requires a cloud-based interface (Connected Data are doing a similar thing with Transporter), however one of the key benefits here is the ability to collate large volumes of anonymised customer data and use that as a basis for improving system resiliency. We are starting to see reliability data sets for hard drives being made freely available (see Backblaze blog) that provides useful data on the most reliable types of drives in varying data usage scenarios. As OneBlox is a BYOD (bring-your-own-drive) solution, any information on drive reliability is a real benefit.

Market View

As a NAS platform, OneBlox has some compelling benefits; customers can mix/match the hardware they need and grow on a granular basis with low incremental costs (a single OneBlox is less than $10,000). The use of object store technology allows scale-out and provides granular CDP. Perhaps the biggest negative at this stage is performance, however this can be addressed by the use of flash drives, assuming the OneBlox software is modified to accommodate this.

Currently the technology is very much focused at small/medium organisations, with a maximum 6-node ring deployment capping out at 288TB. That said, from the presentation and discussions at SFD7, there’s no reason to assume the node count can’t be increased in the future. It’s not surprising that traditional NAS vendors like NetApp are seeing their sales stagnate. Exablox provides a much more compelling solution for on-premises file serving, without the baggage of operating system bloat. It will be interesting to see how the product portfolio expands over the coming 24 months. I for one will be keeping a close watch.

You can see the vidoes on Exablox from Storage Field Day 7 here:

Exablox Presents at Storage Field Day 7 (Tech Field Day Website)

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(Note a couple of changes have been made to indicate that NFSv3 is supported on both hardware platforms, plus an increase in ring capacity)

Disclaimer: I was personally invited to attend Storage Field Day 7, with the event team covering my travel and accommodation costs. However I was not compensated for my time. I am not required to blog on any content; blog posts are not edited or reviewed by the presenters or Tech Field Day team before publication. Connected Data provided all SFD7 attendees with a complimentary Transporter Personal device.