I didn’t know that RAID was a bad word, much less a bad acronym, unless you are an insect. But after reading the Drobo product literature and watching Robert Scoble’s interview with the Data Robotics, Inc. management team, it became clear that Drobo’s marketing machine wants nothing to do with the term RAID. Apparently RAID has become synonymous with enterprise-level, expensive, hard to setup, and hard to maintain. Wanting to target small businesses, small offices, and home users, Data Robotics, Inc. calls their product a Data Robot (Drobo for short); a protected storage solution which uses industry standard data protection methods. Marketing gloss aside, I think that the Drobo product embraces the best of what RAID was supposed to mean: Redundant Array of Inexpensive (or Interchangeable) disks.
The Drobo unit accepts up to 4 disks, and will take any 3.5″ form factor Serial ATA disks you already have, or purchase and optimizes them to run as one large virtualized disk. No matter what size the disks are (unlike other RAID solutions, the disks do not need to be the same size in the Drobo appliance), the Drobo operating system will build the largest volume possible while providing at least a minimum level of protection against hardware failure. Whether it’s just two disks, on which it builds a mirror (equivalent to RAID1) or three or more disks where it creates a striped set with parity (equivalent RAID 5), the Drobo OS takes care of all of the configuration for you. It will even build a redundant mirror when a single disk is inserted. However since a single disk mirror will still fail if the single disk stops spinning, I do not recommend relying on this configuration for hardware data protection. The Drobo appliance will even rebuild and resize the partitions when additional hard drives are inserted in real-time without the need to bring the volume offline.
I’ve been evaluating my Drobo unit for two weeks now, and I set it up to run attached to a Mac Mini, which acts as my office server and media center. I can then share my files with my other computers using several protocols including Samba, Apple FileShare, or SSHFS. The unit was easy to set up, and runs very smoothly. With the exception of some noise when the cooling fan ramps up to full speed, the unit is normally very quiet. I purchased the $500 Drobo appliance, but I already owned the four disks that I put into the unit, all 200GB drives. This configuration gives me a total of 550 GB of space to hold my data. The remainder of the space is reserved for data protection and for system overhead. As drives fail, or as I need to expand my storage, I can simply upgrade the disks one by one and without taking the appliance offline. I will simply slip out the oldest or smallest drive and insert the new one. After a few minutes, the Drobo appliance will have formatted the drive and resized the volume to utilize the new disks.
Although I am very happy with the data protection that the Drobo appliance provides, I do not consider it an excuse to not backup. A protected storage appliance like this will not protect me from fire, flood, or other disaster, so I still backup all of my critical files nightly to a removable drive which I swap out each week and take with me off site. In the future, I plan to setup an rsync relationship with a computer at my house and move all of the changed files across the wire each night through a cron job. But that’s a project for another day. All and all, I’m very happy with my Drobo appliance and would recommend it for individual users and small offices with large storage needs, but who do not have large throughput needs. The Drobo appliance attaches to the host system using USB 2.0 and the specifications claim that it has a sustained transfer rate of 22 MB/s. This is enough for an individual to run a video editing project on it, but it may bottleneck when I/O intensive databases try to move large chunks back and forth. At that level, you would need to build a more enterprisey RAID solution anyway.
