After giving much thought to the question, I have finally decided to stick with Drobo, and I have bought a new unit, the 5D. Wouldn’t I have preferred to create my own ZFS system? Yes indeed, but I have not done so, for the following reasons:

• In order to properly run ZFS you need a fully fledged computer, with a considerable amount of RAM (8GB being the bare minimum);
• If you are serious about it, the RAM has to be ECC: this is important, or you might end up with data corruption because of uncorrected errors in the RAM; ECC RAM is not a problem in itself (just more expensive), but it implies that you won't buy an entry level PC as file server, or it won't support the error correction;
• My main system is Mac OS X, and ZFS does not support a number of features of OS X, notably Spotlight and Time Machine; all this will likely come, but it’s not clear when;
• Although I would be pretty much certain of being able to read my data if the system failed, the downtime could be quite high (I would need to find a system capable of hosting all the disks, install a compatible version of Linux or FreeBSD, etc.).

Also, there are a number of things I like about Drobo:

• It does work: I have a Drobo 2nd generation that I bought in 2007 (replaced once in 2013, even though out of warranty), which has been working flawlessly 24/7, and always recovered my data when a disk failed (this happened twice);
• The support is stellar: I have local support in Singapore, the people who pick up the phone are knowledgeable and seem to care, and they go beyond the warranty clauses (as said, they replaced my 2nd generation Drobo with a new unit, even though the warranty expired several years ago);
• I do not need to think, and there are no possible mistakes I could make: I just put the disks in, and forget it;
• The new units offer dual disk redundancy, so I can sleep at night when a disk fails…

First impressions with the Drobo 5D

After one week I have not found many defects in the Drobo 5D. It is silent, more so than the previous generation. The disks from my old 2nd generation Drobo were immediately recognized, and the new 3TB disk I have inserted was also instantly available. As soon as I have switched to dual disk redundancy, the unit told me that during the re-layout it could only recover from one disk failing, as expected. The re-layout itself was quite fast, and my data was available during the process. On the negative side, the Drobo is slower than competing products, but I don’t need more speed than what it provides. To be honest, my old 2nd gen. was already fast enough for my needs, and this is about 10 times faster. Unfortunately I don’t have a Thunderbolt plug on my Mac Pro 2010, but I have bought a cheap USB 3.0 PCI card and it works great. To give you some references, I have all Lightroom masters stored on the Drobo, as well as my entire iTunes library, and a number of VMware Virtual Machines (which I run directly from the Drobo).

As of now I have 4 X 1TB disks, and 1 x 3TB. I plan to replace two small disks with two more 3TB, so I’ll have some more space, and I can use the two 1TB in the old Drobo, which I would connect to one of my Airport Express and use for some additional backup.

While Drobo is not the perfect solution, I haven’t found any better options today, by far. Moreover, there are a couple of nice additional features on the 5D: a battery, which can keep uncommitted data in memory in case of power failure. Uncommitted data will be written to disk when the power is restored, protecting you from file-system corruption. If you need more speed, you can add an SSD (without using one of the HD bays), which the unit will use as cache. Again, the current speed is sufficient for me, so I have no plans to do that. Last but not least, the Drobo periodically scrubs the disks, looking for bad sectors. This is probably not as effective as what ZFS or Btrfs do, but it does provide an additional safeguard to maintain the integrity of your data.

I am still planning to build a fully automated integrity checker app for the Mac, and maybe add some recovery features (by storing redundant data). I have not had much time to work on that yet, but it’s quite high on my todo list.

Disclaimer: I am not affiliated with Drobo in any way.