At first glance the new DroboElite storage appliance from Data Robotics looks exactly like the DroboPro we reviewed last year. It’s black, it’s shiny, and it can be fitted with up to eight SATA hard disks. More than that it employs the same BeyondRAID technology to manage its storage and provide a high level of redundancy with hardly any need for manual intervention. Unlike the DroboPro, however, the DroboElite is designed solely to be shared on an iSCSI Storage Area Network, or SAN.
Unlike most other SAN appliances the DroboElite is aimed at small companies with little or no networking expertise. So, for example, it’s not at all fussy about what disks you put in it, who makes them or how big they are. Neither do you need special tools or carriers: just slide the bare disks into the slots behind the pull-off front cover.
There’s hardly any management needed either, the BeyondRAID technology working out what type of data protection to apply based on the number of disks you put in and their capacities. You can start with just two if you want, although three are needed to get the equivalent of RAID 5 protection to allow the array to continue working even if one of the disks fails. You can even protect against two simultaneous drive failures, although you’ll need four or more disks for this, and some capacity will be lost if you do.
Behind the scenes the processing required is all done in the background so you can carry on working while the array is built or when changes are needed should you plug in other drives later on. Moreover, unlike a traditional RAID setup, there’s no need to take backups and recover data when changes are made. Just plug in a new disk or replace an existing drive with something bigger and you get more space: it’s as simple as that.
What management there is can be done via a simple dashboard utility which lets you configure up to 255 logical volumes across the array. Maximum size is set by the file system involved, with support for up to 16TB volumes when using Windows NTFS.
Another neat feature is that it doesn’t matter if you don’t have enough physical disk space to accommodate the volumes you want. That’s because the DroboElite employs so-called thin-provisioning to only allocate space as required, not up front. Of course, there may come a time when available disk space runs out. But then all you have to do is add more disks or swap existing drives for something bigger and leave the Drobo to shuffle everything around .
Two Gigabit ports are built into the appliance, each with on-board iSCSI support such that the storage can be accessed and managed as though it was directly attached to network servers or PCs. All that’s needed is an iSCSI initiator, and on Windows Vista, Windows 7 and Server 2008 you can use the one Microsoft supplies. On an Apple Mac the Drobo Dashboard will install an initiator for you. Linux and VMware initiators are also supported with minimal setup required regardless of platform, plus optional CHAP authentication if wanted.
We were very impressed both with how easy the DroboElite was to set up and the level of performance it had to offer. For our tests we installed three 500GB disks, then attached the Drobo to a Gigabit switch to which we also connected a Xeon-based server running Windows Server 2008. Using the Microsoft initiator we quickly connected to the array and formatted an NTFS volume before running a series of tests using the open source Iometer tool.
Admittedly we didn’t quite get the same throughput as with an internal array, but on a sequential read test we recorded a throughput of 112MB/sec, close to the maximum possible over a Gigabit Ethernet link. Perceived throughput was good, too, and when copying files and running video it was hard to tell we weren’t using internal storage.
We did have a couple of concerns, one of which was the lack of NAS support which, if present, would make for a much more flexible solution. The other was the £2K+ price tag to which you have to add the cost of disks. That said, if shared by a number of servers, the price isn’t a big deal and is on a par with similar SAN products. Added to which the DroboElite almost looks after itself, the value of which is hard to measure.
Company: Data Robotics
Contact: 0845 409 4525