The Drobo Elite: An iSCSI SAN Made Easy

I recently had an opportunity to review the latest Drobo enterprise solution, the Drobo Elite.  It boasts 8 SATA drive bays and can be configured for either single or dual drive redundancy.  The Drobo Elite, like the rest of Drobo’s product line is RAID made easy.  In truth, its RAID maid drop dead easy.  And with the iSCSI support built into this product, the folks at Data Robotic Inc. (makers of Drobo) have made iSCSI equally easy.

Those familiar with Drobo know that the company has forsaken the traditional RAID paradigm for what it has branded BeyondRAID.  Its not just RAID with a clever little name for marketing reasons.  Its RAID done right.  Its RAID made simple.  While traditional RAID configurations technically allow the mixing of different capacity drives in the array, they do it by sacrificing disk space.  The smallest drive in the array becomes the usable capacity of every drive in the array.  So, with an array made up of one 1TB drive and three 2TB drives, the capacity of each drive becomes 1TB in the eyes of the RAID controller.

Drobo’s BeyondRAID is really RAID re-envisioned.  Its what happens when engineers start from scratch and remake the rules the right way.  BeyondRAID allows the use of mixed drive capacities but it doesn’t resort to the lowest common denominator in order to make the drives usable.  Mixing one 1TB drive with tree 2TB drives is no problem.  The Drobo knows how to access the full capacity of each and allocates space for redundancy to compensate.

Another place were traditional RAID falls apart is migration to larger drives.  With a few rare exceptions, traditional RAID solutions don’t allow the migration of the array from a series of smaller drives to larger mechanisms as they become available.  Drobo makes this easy.  Its literally a matter of popping one drive out of the Drobo and snapping a larger drive in its place.  The Drobo will format and make the new drive a part of the array and then start re-striping the data back across the volumes to provide redundancy.  Just wait for the lights on the Drobo to turn green again indicating the data is safe and its just a matter of replacing another drive to continue migrating data from smaller drives to newer larger disks.  No down time, and the data is safe.  But with traditional RAID, it would have been necessary to backup all of the data to another device, replace all of the drives, then reinitialize the array and copy the data back to it.  That’s not migration, its rebuilding in the most literal sense.

But BeyondRAID isn’t even the killer feature of the Drobo Elite.  BeyondRAID is part of every product Data Robotics builds, be it the end user  4 bay Drobo or their latest enterprise solution, the Drobo Elite.  The impressive feature of the Elite is that rather than being a drive array that is attached directly to a computer for access or sharing, the Elite is a SAN (storage are network) solution.  And the Elite’s SAN support comes via iSCSI.

Most computer users are familiar with file servers and network shares.  A file server makes a network share available to the users of the local area network (LAN).  Users of the LAN can access the share in order to read and write data.  It gets the job done but it doesn’t provide the best possible performance.  Those looking for performance look to iSCSI based solutions.

iSCSI makes remote data available to the computer user similar to a file share in that the data is located out on the network rather than on a local drive.  But iSCSI only allows one user to access a share at a time.  Because the data is accessed at a block level on the drive, only one user can access the data at one time.  An impressive performance increase is the result.

Since one user can access an iSCSI volume at a time, the Drobo allows up to 255 iSCSI volumes per Drobo Elite.  And unlike conventional drive partitions, Drobo Smart Volumes are created to subdivide the total disk space.  Its not necessary to set the min or max size of the Smart Volume since they expand across the array as needed.  There is no need to repartition in order to make more space available to one of the iSCSI Smart Volume targets.  And with a pair of gigabit network ports on the back of the Drobo Elite, its likely the network bandwidth will not be a bottleneck for the data array.  As a bonus, the dual network ports can be set to function in a failover configuration, or they can be attached to separate networks of VLAN’s.  Additionally, if the network switch supports it, the ports can be paired in order to aggregate bandwidth.

Data Robotics didn’t come up RAID— its developers came up with a way to make it simple and thereby better.  And with the Drobo Elite, the same can be said about iSCSI.  Drobo makes it better by making it easier.  Normal iSCSI consists of a Target (the remote data volume to be accessed) and the Initiator (the client component allowing the workstation to access the iSCSI Target).  Traditionally this is a confusing multi-step process configuring the target with network settings and then using odd naming conventions to make the data available to the Initiator on the client computer.

The Drobo simplifies the process by removing the need for the odd naming conventions that are difficult to configure with traditional iSCSI.  Just set an IP address for each port of the Drobo and plug it into the LAN.  Then install the Drobo Dashboard software on the computer that will access the SAN.  The Drobo Dashboard contains its own iSCSI Initiator.  The Dashboard provides an easy to use visual interface displaying the available iSCSI Targets on the network.  Attaching to the target is as simple as checking a box.  The target appears on the workstation desktop as if it were a locally attached drive and the disk is ready to use.  Other users on the network know that the target is already in use because a lock icon appears when the volume is in use.  No painful configuration, and no confusion in use.

So why use iSCSI when its more restrictive than a file share?  The answer is simple: speed!  The Drobo Elite’s use of iSCSI makes a massive amount of data available to anyone on the network at speeds that, in theory, rival that of a locally attached disk drive.  This is ideal for teams of video editors, software developers, or groups that need fast and reliable access to a massive data volume.  And since the Drobo provides redundancy against the failure of one or even two (depending on the initial configuration of the Drobo) drives, the data is far more secure than a network loaded with individual, non-stripped drives.  And since the data is all located in one place, it makes it very easy to backup the Drobo for additional data security.

Sound too good to be true?  Do you think there must be a down side to such data goodness?  In fairness, I can think of one.  While traditional RAID, SAN, and iSCSI based solutions exist, they have prices that differ wildly.  While an 8 drive bay version of the QNAP Pro TS-859 lists for $1618.99, the Drobo Elite lists for $3499.00.  The single down side is price. But what you get for the premium price is a hardware chassis with a fit and finish that puts all others to shame.  You also get a simple and intuitive management console that is easily superior to other solutions.  You also get the ability to mix and match drive sizes without sacrificing space.  This is something I have yet to find in any other solution (if you know of one, please post a note in the comments are below).

Is the Drobo Elite worth the premium price?  In my opinion, hell yes!  But when it comes to justifying the price offset to the company CEO, it might not be as cut and dry.  In evaluating the Drobo Elite for a client, despite my urging to go with with Drobo, the powers that be ended up going with an alternative solution the has a few more options, but much less flexibility and is considerably more effort to maintain.  Its my belief that the Drobo Elite is worth the money.  It provides data security and considerable peace of mind.  There are too many constraints with traditional RAID solutions, and those constraints lead to less flexibility and greater chance of data loss in the long run.  But when money is not the deciding factor, it is my belief that a Drobo solution wins hands down.

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