Edit: I recently replaced the Drobos with a FreeNAS server. You can read about it in my article I Replaced My Drobos With A FreeNAS Server
I build my FreeNAS Server in 2008 with an Intel D945GCLF2 Atom 330 Dual-Core motherboard and CPU and six 1TB WD green drives. This server has been running 24/7 since then without an issue. 7 years have passed and the server has just about run out of space. For a long time, I have been exploring many possible ways to upgrade the server. Whatever way I look at it I had to buy a new motherboard. Plus many hard drives at the same time to upgrade my existing FreeNAS server with enough storage to last the next five-plus years
Raid-Z
The six hard drives are configured in a RAID-Z1 (the ZFS version of RAID 5). Unfortunately, a downside of RAID is that it is not possible to add drives as needed. A traditional RAID consists of a fixed number of identical drives. Upgrading a traditional RAID requires all data to be copied off the RAID and all drives replaced with new drives with a larger capacity. ZFS RAID-Z is more flexible than traditional RAID. It is possible to upgrade a RAID-Z without copying off the data. This is done by replacing each disk with a new disk with a larger capacity and then let it rebuild and then replace the next. When all drives have been replaced, the storage will expand to the new size.
For the past year or so, I have been trying to find a solution to my storage problem. Then one day I mention my problem to a colleague of mine. He then offered me an old Drobo fs he had stopped using a long time ago because he found it too slowly. In fact, he had given it to another colleague of mine first but he returned it because he also found it too slowly. I accepted his offer and a couple of days later he brought the Drobo to the office.
Drobe VS FreeNAS
The Drobo is no match for FreeNAS and Synology when it comes to features. The Drobo fs and N can be extended with apps/plugins. However, there are not many and I do not find those there are very useful because the Drobo has very few resources. However, I do not want the Drobo to run apps anyway. I just want to make my files accessible on the network. There is a small Linux box in front of the NAS running the things a need and do not need the NAS itself to run apps. I prefer to have the NAS server separate from the application server because it is a lot more flexible. For example, I just changed from FreeNAS to Drobo and the only change I had to do on the app server was to mount the share on Drobo instead of the one on FreeNAS.
The feature that makes Drobo special is that Drobo does not use traditional RAID but something they call Beyondraid. With Beyondraid, the drives do not have to be identical and can be of different sizes and from different makers. What I like even better is that I can add drives as needed. Unlike Traditional RAID The Drobo can expand the RAID. This means that I can add drives, as I need more space instead of having to buy all the drives upfront. The Drobo fs can house five drives. So I purchased two new WD red 3TB and added them to the Drobo along with an old Seagate 1.5TB I had lying around. When I need more space. I just add a new drive or replace one of the existing hard drives with one that has a larger capacity.
You might ask why I would ever use a Drobo when ZFS is the king of file systems? Whereas Drobo uses a proprietary file system that is nowhere near as good as that of ZFS.
Convenience
Well, the short answer is price and convenience. However, the long answer is slightly more nuanced than that. When it comes to buying stuff, especially when it comes to technology. I believe in buying what you need and not what you want. Because what I want is a FreeNAS server with 20 6TB hard drives, an Intel Xeon processor, and 96 GB ECC RAM. What I need is an affordable NAS to store my growing media collection and the backup of a couple of computers. I love that the Drobo itself is dead simple to use and that I can add more capacity as needed. So for what I need and want, the Drobo seems to be absolutely perfect.
So there you have it. I just replaced the awesome free and open-source FreeNAS with the not-so-free and very proprietary Drobo. I will return with an update when I have used it for some time.
Edit: You can read my 6 month update here