Review Index:

Data Robotics, Inc. DroboPro 8-Bay In-depth Review

Subject: Storage
Manufacturer: Data Robotics

Enter BeyondRAID / Feature Exploration

BeyondRAID builds on the concepts of RAID, but takes things in an entirely new direction.  The installed drives are treated as a logical storage pool of small data blocks.  Based on the configured level of redundancy (single or double drive failure), each chunk of data is replicated across the drives as it is written.  A remap table is maintained to track what is where and on which drive.  The remap table, along with other metadata is written to all installed drives to increase redundancy of this vital data.

Why jump through all of these extra hoops just to create an array of drives?

  • Most 'normal' arrays require all drives to be the same size.  Treating the installed drives as a pool of blocks lets the DroboPro make the most of the installed drive space even with mixed capacities installed.

Volume Management

Another thing the Drobo does is separate array capacity from physical capacity.  You specify the capacity of an array when it is created.  This capacity has nothing to do with the number or size of drives installed, and can even be *larger* than the total space installed.  I know, this sounds backwards, but it comes in very handy as a method of future proofing your storage.  You set your volume size once.  You create your partition on that volume once.  Expanding available storage by adding drives will never require the extra steps normally required by a traditional RAID.  I know all of you are now wondering how the laws of time and (storage) space are being broken here, well they are only broken in the virtual sense.  DroboPro may be telling the OS it has 16TB available, but remember it intelligently tracks what blocks are in use by the file system.  Storage is therefore limited based on what space is used, not by what space is reported to the OS.

To answer the next question that has likely popped into everyone's head, actual free space available is presented to the user not by the conventional methods, but by a few new ones.  First there is a column of 10 blue LEDs along the right side of the DroboPro.  These display the actual capacity used at roughly 10% per LED.

If the Drobo Dashboard software is installed on the host system, the user gets a pie chart icon located on the taskbar.

Double clicking this icon brings up the Dashboard itself, giving a bit more detail.

Double clicking the pie chart pulls up the Advanced Controls window, which mirrors the front panel of the DroboPro right down to the current status of all front panel LEDs.  The 'Tools' tab opens up a bunch of other options to be covered later in this article.

Other (non-Drobo) arrays follow a fairly standard data structure, and failed arrays can usually be recovered with special tools and sufficient know-how.  The same can not be said for BeyondRAID, as the features it brings to the table require a proprietary, metadata-driven structure.  Drobo assures me their implementation is highly robust and resistant to corruption and failure.  Having performed my own data recovery from personal failed arrays, it is going to take some serious convincing to get me to trust my own data to one of these puppies.  Later on in this review I will be giving the DroboPro a serious shakedown, but first we need to cover the plethora of additional features available once the unit is up and running.