Get ready for a rather lengthy (and somewhat technical) blog post. Hopefully, it will be worth the read, particularly for those interested in storage alternatives for home offices requiring more storage than the typical external hard drive.
I first heard of Drobo some years back on MacBreak Weekly, a tech podcast hosted by Leo LaPorte and his TWIT.TV network that I never miss. Drobo has been a frequent sponsor of MacBreak Weekly, MacOSKen, and a few of the other podcasts I tune into regularly. I never thought I would be a candidate for their storage products, but when I recently upgraded Huguette's desktop computer from a 2007 Mac Pro to a 2015 iMac, I realized that I needed to look into other approaches, as I would be losing the convenience of four internal drive bays that were on board the old Mac Pro. An iMac has a single internal drive, so everything else would need to be external, unlike the Mac Pro.
First, I should describe the backup system that was in place for her Mac Pro, which has been the repository of a collection of some 35,000 photos that comprise much of her life's work as an artist and photographer. A multiple backup strategy is essential for something this irreplaceable, so I have been employing the "3-2-1 backup" strategy you may have read about elsewhere, which essentially means, "at least 3 copies of your data, stored on at least two devices, with one of them being offsite."
This was accomplished on her Mac Pro by having her primary (1TB) drive in Bay 1 being backed up to 1) a bootable SuperDuper-based (1TB) clone in Bay 2 for immediate recovery in case of failure of the Bay 1 drive, 2) a Time Machine backup to a 2TB drive in Bay 3 (2TB in size because Time Machine stores historical copies of previous versions of files with an ever-increasing need for space, unlike a clone that only has the latest version of each file and tends not to grow much in size), and 3) an off-site backup to Carbonite.com in case the house ever burnt down or whatever other calamity one can imagine might occur.
With the new iMac, I knew I didn't want multiple external drives hanging off the back of her iMac (somewhat unsightly as well as confusing). I also decided that it was no longer necessary to be running a separate Time Machine backup. The need for recovery of a specific historical file has yet to present itself in the many years of our individual use of our computers since Time Machine was rolled out by Apple. I'd much rather have an up-to-date bootable clone to use in case I ever find myself in the dreaded "dead drive" scenario. Also, access to "previous versions" of files is now being offered by other products, one of which I will mention shortly.
There was one more consideration affecting the ultimate choice of backup strategies for Huguette's new IMac, since we ended up choosing to have a 500GB solid state drive as her startup disk for her new computer to optimize performance of image handling for her photographic work. This meant that we would need an external drive just to house additional primary data storage, since 500GB was not nearly enough to handle her existing storage needs. So we bought a 3TB external Thunderbolt drive when we purchased the new iMac to handle whatever additional primary storage she needed.
With all this said, what, you may ask, has turned out to be the "secret sauce" of the new backup approach? Enter the Drobo 5N, a 5-bay "network-attached-storage" (NAS) device that accepts up to 5 internal hard drives that work in concert to act as one big drive, but with one very important difference from "one big drive". The Drobo manages the storage in a way that provides data protection against any single drive failure. As such, it provides the "2" of the "3-2-1" backup strategy, in that each data file of your backup is stored on two different physical devices within the Drobo. It achieves this by setting aside a portion of the total storage capacity of the drives installed in the Drobo for "protection" in case one of the existing drives has a failure. This makes it a considerably more robust backup storage device than a single external hard drive.
I configured my Drobo 5N with three internal drives (2 1TB drives and 1 2TB drive) harvested from the old Mac Pro and purchased two new 4TB drives to round out the total storage capacity at 12TB. This created a little over 7TB of usable backup space to house the total combined backup size for the three primary volumes on our two iMacs combined: my internal 3 TB drive and Huguette's 0.5TB internal SSD drive and external 3TB Thunderbolt drive.
The next step was to create "shares" for each of these volumes on the Drobo so that I could create a backup process for each of the three primary volumes to be contained discretely in each of these shares. One of the very nice things about the Drobo shares is that, unlike fixed partitions on a hard drive, shares don't need to be predefined for a particular size (unless you are wanting to set up a Time Machine backup). As a result, the full 7TB is available to house the collective backups of the three primary volumes and the shares will dynamically be resized as needed to accommodate any growth in the backups' needed storage space. In fact, I can create additional shares if desired, subject to the total available space in the Drobo.
The Drobo site makes some suggestions as to possible backup software and I adopted their recommendation to use Carbon Copy Cloner (CCC). For years, I had been using SuperDuper with great success, but with the new approach of multiple shares on the Drobo, I felt that their recommendations carried a lot of weight so I went with CCC and I have been pleasantly surprised thus far.
One thing I haven't mentioned yet is how the data makes its way from the primary volumes to the Drobo for backup purposes. The answer is: a wired "home network" running gigabit Ethernet. This connectivity is accomplished through my wired home network via an Apple AirPort Extreme router that also serves as our wireless router for our mobile devices, Apple TV's and other various wireless devices in the house. The AirPort Extreme base station has wired Ethernet connectors, to which the Drobo is connected. Our two iMacs are also connected to the router via gigabit Ethernet cabling through a switch connected to the router.
If all this is too much tech-speak, think of the Ethernet wiring as providing the "rails" on which the data packets ("trains") run to shuttle data via the router ("roundhouse") to and from the Macs and the Drobo at reasonably high speed. And importantly, the connection to the Macs is a simple, unobtrusive cable that is out of sight.
With all the hardware, wiring and configuration in place, I set about creating the actual backups of each of the three volumes and also setting up a daily schedule for them to update automatically in the middle of the night. I staggered the timing of the schedules so that the three backup routines would not be hitting the Drobo at the same time. All is working very well thus far.
My Carbon Copy Cloner backups are clones of my data files but are not bootable backups, as the Drobo does not support this. As a result, I decided to deploy two existing external hard drives to serve as bootable backups (again using CCC) so that I would have both the "belt" and the "suspenders" in the event of a failure. This will make it easy to immediately restore or rebuild a new internal drive containing the operating system and applications in the configuration that we need, in the event of a catastrophic failure.
I will close by saying that the Drobo hardware has an "industrial strength" feel to it and uses an array of lights on the front to indicate the status of the disk in each drive bay, as well as additional lights to indicate the percentage of storage in use and when disk activity is occurring. All in all, the Drobo 5N has met and exceeded my expectations and it gives us plenty of room to grow as our digital assets in the form of photos, videos, music, and documents continue their relentless expansion as the relics of a material world find themselves transformed into 1's and 0's.