Caption by: Alan Stevens
Unlike the majority of small-business storage appliances, the Drobo B1200i isn't a NAS (Network Attached Storage) device with iSCSI tacked on as an afterthought. No, it's iSCSI through and through, with room for 12 drives protected by Drobo's unique BeyondRAID technology. More than that, three of those drives are solid state, adding what Drobo calls 'data-aware tiering' — an option normally only found on expensive enterprise products, whereby the most important and frequently accessed data is migrated to the faster SSD drives to boost performance.
What you get
A hefty piece of kit, the B1200i comes in a 3U black metal box that can be desk mounted, but is really best located in a datacentre rack. Not least because it's very noisy, with four hot-swappable fans at the rear and two more in each of the dual, redundant, power supplies (which can also be hot-swapped). We tried sitting next to it for a while, but soon moved to another room.
Four Gigabit Ethernet ports are also to be found at the rear of the B1200i enclosure, one dedicated to management while the other three are for iSCSI SAN attachment. In an ideal world these would be connected either directly to servers or, where than three are involved, to a dedicated storage network. However, there's nothing to stop you using a mixed infrastructure or managing the Drobo over the iSCSI ports. It's all very flexible.
All about the storage
The disks are inserted from the front, with twelve 3.5in. hot-swap bays into which, in theory, SATA or SAS drives can be inserted. It's worth noting, however, that for performance and availability SAS is the preferred option. It's not possible to mix the two technologies in the same enclosure.
Disks simply slide into place without the need for carriers, and there's a cover that goes across the whole appliance, held on by magnets. There's no lock to prevent accidental disk removal or tampering but, as the B1200i will usually be locked away inside a datacentre or server room, that's not a major concern.
Unlike other Drobo products, the B1200i is sold ready-populated with disks — apparently to avoid customers installing cheap consumer-quality drives, and then complaining about a lack of performance! Prices start at £7,680 (ex. VAT) for which you'll get six 2TB SAS disks. For our tests, we used a top-end configuration that sells for £11,500 (ex. VAT). This came fully loaded with nine 2TB SAS drives (Drobo currently supplies 7,200rpm Seagate Constellation ES disks here), plus three 200GB OCZ Talos SSDs for tiering.
Putting the Drobo to work
To get started all we had to do was load up the disks, cable the Drobo to our network and switch it on. We then installed the Drobo Dashboard, a remote console that can be deployed on either Windows or Mac systems, to manage and monitor the Drobo hardware.
Not that there was much to do, as Drobo's main selling point is that it's a hands-off solution calling for very little in the way of management or technical expertise. In fact, just about everything is done by the BeyondRAID firmware, starting with automatic building of a suitable disk array dependent on the number and size of disks inserted, complete with an appropriate level of RAID protection to continue working in the event of a hardware failure.
Protection against two simultaneous disk failures is applied by default, although you can switch to one to liberate extra storage, if required.
And that's about it as far as the array setup is concerned. You're told very little about what has actually been chosen — but then, you really don't need to know: it just works.
Another plus is that the available disk storage is all aggregated into a single pool from which you can configure up to 255 16TB volumes. Now clearly that's much, much more than the physical capacity (just over 12TB), but thin provisioning means you don't have to worry how much 'real' storage there is.
Of course there will come a time when extra physical space is needed, in which case it's simply a matter of inserting an extra disk or two if you have empty bays or, more likely, swapping out existing disks for larger models. The current firmware can handle disks up to 4TB.
Simple traffic-light LEDs to tell you when a drive has failed or space is running low and dealing with such issues is, again, a 'no-brainer' with the necessary reconfiguration all done behind the scenes. There's no need for any kind of user interaction or much of a perceivable impact on performance or availability.
We tested using Windows Server 2008 R2, but the Drobo B1200i can also be connected to Mac and Linux systems, as well as VMware and Citrix hypervisors, with facilities to handle NTFS, HFS+, ext3, VMFS, and FAT32 file systems. Creating new volumes is incredibly straightforward with, on Windows, everything done from the Drobo Dashboard, including mounting of volumes.
Just like the big boys
The hands-off management approach continues even as far as the data-aware tiering with, unlike some products with this option, no need for any manual data migration or extra tuning to make it work. If the SSDs are there it just starts working, the firmware calculating where the data hotspots are and migrating that data from the magnetic spindles to the faster solid-state drives.
To do this, the Drobo examines the data streams it's processing, identifying data from non-data and distinguishing between streamed data blocks written sequentially to disk (typically when documents are opened, files copied and so on) and transactional data written and accessed in a more random fashion (as on email and database servers). Streamed data is directed to the magnetic storage, while transactional data is hived off to the faster SSD tier.
We tested the B1200i using Iometer and with sequential workloads got data transfer rates of up to 120MB/s using a single iSCSI port cabled to a Windows Server 2008 R2 host. With a random workload, data throughput dropped as expected, but we recorded over 770 IOPS (Input/Output Operations Per Second) on each port which, with three servers attached, meant in excess of 2,300 IOPS overall. This is impressive on a small-business appliance, most of which struggle with this kind of workload generated by email, database and other commonly deployed servers.
There are a few things missing from the Drobo B1200i, such as a lack of 10GbE connectivity, which limits its scalability. Deduplication and data snapshot facilities are also absent, although these can be done at the application and OS level. Such niggles aside, it's hard to find an alternative storage solution in this price bracket that's as easy to manage or capable of delivering what the impressive Drobo B1200i has to offer.
Caption by: Alan Stevens
Caption by: Alan Stevens