Dec 112016

When the digital revolution arrived to photography, one of the side-effects was a demand for enterprise class storage even by the most amateur of photographers. Every digital photography course ever offered has always hammered this point:

Always use the best quality storage devices and always make sure you have two backups.

Some have gone so far as to add a third off-site backup. The issue here is that the larger the storage device, the greater it’s cost. Large, well funded companies can afford mega-sized drives, but how do the smaller guys do it? Coming from an information technology background, I can tell you that we ran into this issue ages ago. The answer was something called RAID. RAID is actually an acronym which stands for Redundant Array of Inexpensive Drives and it is a technology that allows you to group multiple smaller drives together to present themselves as a single, larger drive. RAID has multiple methods for performing this little feat, but the most common one is called block-level striping with distributed parity or RAID 5.

What’s so great about that?

Well for one thing, it allows you to, as previously mentioned, gang smaller drives together and have them behave a single, larger drive. It also provides protection in case a drive fails by backing up an individual drive’s data onto all of the other drives. Should a drive fail, the RAID 5 Array will continue to function and when the failed drive is replaced, and it can automatically repopulate the new drive with the data of the failed drive including any changes to the data that have occurred since the drive failed. What if two drives fail? Well with RAID 5, you are pretty much hosed.


In the case of wanting to protect against the simultaneous failure of two drives, RAID 6 (block-level striping with double distributed parity) should be used as this maintains two parity stripes and can handle two simultaneously failed drives.


Both RAID levels 5 and 6 allow for improved read performance as read requests are distributed over all of the drives. The more drives in the array, the faster the read speeds.

Sounds great! Is there a downside?

All is not beer and skittles in the land of RAID. There are certain penalties to be paid for these levels of speed and data protection. First off, any RAID array requires that all drives in the array be of the same size. Add a 4TB drive to an array of 2TB drives and only 2TB of the larger drive will be used. Setup of the array is a long process with striping of large drives taking up to 24 hours. With RAID 5, a minimum of three (3) drives are required to create the array. With RAID 6, a minimum of four (4) drives are needed. There is a storage cost as well: RAID 5 has a space efficiency formula of:


Whereas RAID-6 has a space efficiency formula of:


What these formulas mean is that the space cost of the levels of data protection provided by RAIDs 5 and 6 are dependent on the number of drives involved. For example: if you have a RAID array of 5 x 2TB drives, a RAID 5 configuration would leave you with 80% of the total space available for use and a RAID 6 would leave you with 60% available (8TB and 6TB respectively in our 5 x 2TB array).

On top of that, RAID arrays require battery backups so that, in case of power failure, they can complete any writes they have pending.

Enter Drobo

In June 2007, Drobo Inc. (then called Data Robotics, Inc.) introduced their line of storage devices which promised RAID-like storage without some of the downsides of traditional RAID arrays. All Drobo devices (including the 5C I was sent for review) can pool different sized drives together and still provide data protection. Using a technology called BeyondRAID, Drobo devices can quickly and simply allow you to set up a pooled storage array using any drives you happen to have on hand.

Like a traditional RAID array, some of the storage space is sacrificed for the sake of data protection. Since the Drobo can sport drives of varying sizes, you will lose the space roughly equivalent to the largest drive installed in the array. More so if you select dual drive redundancy (a feature that mimics RAID 6 in the number of drives protected from failure).

There are various models of the Drobo, with some of the Pro models supporting up to 12 drives. The latest is the Drobo 5C, a 5-bay device which uses a SuperSpeed USB 3.1 port to provide extremely fast, locally attached storage. Unlike the 5N or Pro models, the 5C does not contain a built-in Ethernet port and cannot run as a standalone device. However, the use of a USB-C 3.1 port makes it compatible with PCs and Macs.

The Drobo 5C is very reasonably priced at $349 USD.


I received the Drobo 5C in a well-designed package. Custom molded plastic inserts kept the unit rock-steady during transport. I recommend you store the box in case you need to have your Drobo 5C serviced.

All of the necessary cables are included, however, the USB-C cable included is one (1) meter in length and depending on your configuration may not be long enough to reach your PC. I ordered a two (2) meter USB-C cable from Amazon to allow the Drobo 5C to sit comfortably on my desk and connect to my tower PC case underneath.

After that, just plug in the Drobo, insert the drives (a tool-less procedure), install the Drobo Dashboard software and then power the unit up. The Drobo Dashboard then detects the new Drobo and automatically begins the setup wizard, configuring your Drobo as a 64TB volume (!) and formatting it and mounting it automatically on your system. Drive format is selected automatically based on the host machine.

For the record, I used Western Digital 4TB Red drives which are configured for NAS use. Desktop drives can be used but, your mileage may vary. “Green”-type drive are not recommended as they are designed to spin-down to conserve power with greater frequency than desktop drives.

It is interesting to note that the Drobo accomplishes this feat by first formatting the drives as DroboFS (a proprietary drive format) and then creates a partition on top of that. In my case, the partition was formatted NTFS. I then proceeded to copy the contents of an external drive via a USB 3.0 “drive toaster” style adapter. Once that process completed (~2 hours because of the USB 3.0 device), I then added that drive to the Drobo, and my available space expanded automatically.

Despite the Drobo 5C reporting itself as a 64TB volume, the Dashboard app keeps track of your actual storage. A set of blue telltale LEDs along the bottom front of the enclosure give you a quick idea of how much storage you have used.

When the inevitable happens and a drive fills up, the Drobo will shuffle the data around to the other drives and make the full drive able to be replaced. Drive insertion/removal is a hot-swap feature meaning that no reboots are necessary.

In Operation

So far, the Drobo 5C has sat humming quietly on my desk happily digesting all of the data I can throw at it. I even migrated my photo archives off of my NAS to it. This does not mean I am crazy enough to totally rely on it. It is not infallible. I also use an online cloud backup service called CrashPlan to keep offsite copies of my data. Ultimately, I plan on re-tasking my existing NAS to act as a local backup target for CrashPlan, I will have my three tiered backup solution in place.

What the Drobo 5C is not:

  • It’s not a NAS – The Drobo 5C is a locally attached storage device (fancy IT-speak for an external drive) and outside of its Dashboard application, it contains very little user-accessible smarts and almost no surplus processing power. It can be shared on a network via the host computer and can be connected to a server to enable additional functionality, but at its heart, it’s a USB Drive. Other Drobo models, like the 5N or the Pro models have built-in Ethernet ports and NAS functionality
  • It does not have apps or an app store – NAS makers have gone a long way to add extensibility to their devices turning them into light duty servers. E-mail, database, & web servers are not uncommon on most NAS devices. Some of the more heavily specified ones can even act as media servers with trans-coding facilities.
  • It’s not the end-all, be-all of storage devices – While the Drobo 5C makes it very simple for an ordinary person to set up a pooled storage array, it is by no means foolproof or indestructible. Always keep a second backup elsewhere and an offsite copy if you can afford it.

What the Drobo 5C is:

  • Easy – I have over 30 years of IT experience under my belt and can safely say that this is the easiest, fastest, and simplest RAID type storage device I have ever had the pleasure to set up. “Classic” RAID arrays usually involve futzing with DIP switches or using BIOS level menus which are convoluted at best (and that, by the way, is a far cry from the days when this stuff had to be configured from the command line). This device has you install its Dashboard app, toolessly pop in some drives (which do not have to match in capacity) and turn it on. The rest is pretty self-configuring.
  • Fast – The Drobo 5C uses a SuperSpeed USB 3.1 connection via a USB-C interface. I ran the CrystalDiskMark Hard Disk Benchmark and these are the results I got:
CrystalDiskMark 5.2.0 x64 (UWP) 
(C) 2007-2016 hiyohiyo
Crystal Dew World :

* MB/s = 1,000,000 bytes/s [SATA/600 = 600,000,000 bytes/s]
* KB = 1000 bytes, KiB = 1024 bytes
   Sequential Read (Q= 32,T= 1) :   125.572 MB/s
  Sequential Write (Q= 32,T= 1) :   133.586 MB/s
  Random Read 4KiB (Q= 32,T= 1) :     0.945 MB/s [   230.7 IOPS]
 Random Write 4KiB (Q= 32,T= 1) :     4.378 MB/s [  1068.8 IOPS]
         Sequential Read (T= 1) :   180.531 MB/s
        Sequential Write (T= 1) :   211.166 MB/s
   Random Read 4KiB (Q= 1,T= 1) :     0.954 MB/s [   232.9 IOPS]
  Random Write 4KiB (Q= 1,T= 1) :     4.629 MB/s [  1130.1 IOPS]

  Test : 1024 MiB [F: 5.3% (3505.2/65535.9 GiB)] (x5)  [Interval=5 sec]
  Date : 2016/12/10 3:05:49
    OS : Windows 10 Professional [10.0 Build 14393] (x64)

By comparison here are the results I got from my boot drive (m.2 PCI SSD):

CrystalDiskMark 5.2.0 x64 (UWP) 
(C) 2007-2016 hiyohiyo
Crystal Dew World :

* MB/s = 1,000,000 bytes/s [SATA/600 = 600,000,000 bytes/s]
* KB = 1000 bytes, KiB = 1024 bytes

   Sequential Read (Q= 32,T= 1) :  1808.365 MB/s
  Sequential Write (Q= 32,T= 1) :   581.366 MB/s
  Random Read 4KiB (Q= 32,T= 1) :   444.123 MB/s [108428.5 IOPS]
 Random Write 4KiB (Q= 32,T= 1) :   433.819 MB/s [105912.8 IOPS]
         Sequential Read (T= 1) :  1120.062 MB/s
        Sequential Write (T= 1) :   465.360 MB/s
   Random Read 4KiB (Q= 1,T= 1) :    35.284 MB/s [  8614.3 IOPS]
  Random Write 4KiB (Q= 1,T= 1) :   150.260 MB/s [ 36684.6 IOPS]

  Test : 1024 MiB [C: 52.5% (250.3/476.4 GiB)] (x5)  [Interval=5 sec]
  Date : 2016/12/10 3:25:50
    OS : Windows 10 Professional [10.0 Build 14393] (x64)

OK, so that wasn’t very fair. How about against a classic RAID-5 array using SATA/600 drives?

CrystalDiskMark 5.2.0 x64 (UWP) 
(C) 2007-2016 hiyohiyo
Crystal Dew World :

* MB/s = 1,000,000 bytes/s [SATA/600 = 600,000,000 bytes/s]
* KB = 1000 bytes, KiB = 1024 bytes

   Sequential Read (Q= 32,T= 1) :   163.728 MB/s
  Sequential Write (Q= 32,T= 1) :    25.323 MB/s
  Random Read 4KiB (Q= 32,T= 1) :     2.434 MB/s [   594.2 IOPS]
 Random Write 4KiB (Q= 32,T= 1) :     0.740 MB/s [   180.7 IOPS]
         Sequential Read (T= 1) :   160.616 MB/s
        Sequential Write (T= 1) :    20.969 MB/s
   Random Read 4KiB (Q= 1,T= 1) :     1.175 MB/s [   286.9 IOPS]
  Random Write 4KiB (Q= 1,T= 1) :     0.247 MB/s [    60.3 IOPS]

  Test : 1024 MiB [D: 26.4% (737.1/2794.4 GiB)] (x5)  [Interval=5 sec]
  Date : 2016/12/10 3:33:44
    OS : Windows 10 Professional [10.0 Build 14393] (x64)

Interestingly enough, the Classic RAID-5 array over twice as fast reading data than the Drobo 5C (594.2 IOPS vs 230.7 IOPS) but the Drobo 5C blows the RAID Array away in write speed (1,068.8 IOPS vs 180.7 IOPS). For the record, M.2 PCI SSD obliterates the other two down to their component atoms (108,428.5 IOPS vs 594.2 IOPS vs 230.7 IOPS and 105,912.8 IOPS vs 1068.8 IOPS vs 180.7 IOPS). For me, the Drobo 5C’s excellent write performance is perfect for archival storage and backups. There’s even a function on the Drobo Dashboard to enable a backup mode which allows the Drobo 5C to act as a target for Time Machine or Windows Backup/Restore.

  • Expandable – Classic RAID arrays require you to mount the same sized drive across the entire array. Insert a 3TB drive in an array of 2TB drives and (if you are lucky and your RAID controller is reasonably intelligent) it will only use 2TB of the 3TB drive and 1TB will be wasted. Not so with the Drobo. Plug in any combination of drives and all will be used. If one gets full, the system shuffles data around and asks you to replace it with a larger drive. Once 16TB drives become available, Drobo will likely update their firmware to deal with them.
  • Cool and Quiet – My Drobo unit sits on my desk next to my monitor. If it did not have its array of LED lights informing me that the drive bays are populated and the blinking read/write LED at the bottom, I would never know it was on. The outer metal casing is always cool to the touch even under heavy load.


The Drobo 5C is the latest iteration of the easiest to use RAID-like storage system on the planet. This model is a direct attached storage device much like an external USB drive. At $349 USD, the barrier to entry has been lowered so that anyone can have an enterprise class storage solution at their home or office. The Drobo 5C is a USB 3.1 device with a USB-C type connector. With faster write speeds than classic RAID-5 arrays, the Drobo 5C is an excellent target for backups. This feature is also handy for capturing surveillance footage. Drobo offers a data protection plan to cover the cost of data recovery should you run into a hardware problem. I highly recommend you pick that up as your alternative would be to keep a spare Drobo 5C on hand or pay through the nose for a 3rd party data recovery service. Remember, this device, or any other for that matter, is not the end-all be-all storage solution for your data needs. It is an excellent component for creating a comprehensive solution to protect your data.


Feel free to voice your opinion...

%d bloggers like this: