A few months ago I had the good fortune of attending Storage Field Day in San Jose, California where I got to visit Drobo and learn about some pretty sweet new storage technology, including the B1200i. I have been toying with the B1200i for a couple of months, so in this post, I’ll share my experience in working with it.

The B1200i

The unit I received for testing came with nine 2TB SATA disks and three 200GB SSD disks for a usable total of 12.1 TB of storage. With three iSCSI data ports and a management port, all running at 1Gb, on the back there is no shortage of connectivity.

Configuration initially wasn’t too bad; the management port is configured to get a DHCP address from the network you have connected to and from there the Drobo Dashboard gets things off the ground with little other information required.

The Dashboard

You manage the Drobo application from the Dashboard. As long as your computer is on the same subnet as the management interface of the Drobo, the B1200i shows up right away. If you happen to be plugged into a network that is not configured for DHCP, the Dashboard will not find the storage because the management port will have no IP configuration.

Figure A

Drobo Dashboard (click to enlarge images)

Once you have connected to the Drobo, configuring the iSCSI ports is extremely straight forward. Select the Drobo you wish to manage on the main screen of the Dashboard, choose Settings from the Navigation strip, and then select Network from the submenu.

In here, you can select each iSCSI port and assign an IP address, making sure to save your configuration changes when completed.

Figure B

Configuring iSCSI addresses

Note: Once you have your configuration saved, it might be a good time to assign and record a password for the management of your Drobo, just to ensure you are the only one accessing the device.

Using the B1200i

With everything all set and ready to go, the next thing to do is create some volumes on the array. In testing I stuck to fairly small volumes but the volumes you can create might run all the way up to 16TB.

To create a volume, complete the following steps:

  • Select the icon for your Drobo B1200i in the center pane of the Dashboard.
  • Select Volumes.
  • In the volumes pane, select Add Volume.
  • Select the format type for the volume and click Next.
  • Move the slider to choose a size for the volume and click Next.
  • Enter a name for the volume (Drobo is the default) and click Finish.
  • To create the volume, click Apply from the volumes pane.

Once there are volumes, you can attach them to your computer by using the Dashboard and checking the box next to the volume in the list, or you can close the Dashboard and attach them to a server (or servers) to provide primary or backup storage for your environment.

The B1200i does support Multi-Path I/O (MPIO) if your operating system supports it. In Windows 2008 R2 you will need to enable the MPIO features in Windows before this can be configured.

The data

After I got the B1200i set up to test, I started using the array. I downloaded content to it and used files stored on it and found the general day-to-day performance to be very consistent. I did not have an organization full of users on the array copying, reading, and writing data, but I managed to perform some throughput testing while the Drobo was empty and while I was writing other data to it, and I didn’t see much slow-down.

When I tested the speed of the 1200i, the IOPS were not as high as I thought they might be with three iSCSI connections hooked up and MPIO enabled on the Windows 2008R2 test server I was using.

With the tiering turned off, the throughput for a 4K random write averaged about 300 IOPS when running the test for two minutes.

Wait Tiering, on a Drobo?

When you insert two or more SSDs into the 1200i, tiering is enabled by default. This allows the array to manage hot and cold data appropriately by moving it between traditional SATA storage and SSD.

When tiering was enabled, I ran the initial test of a 4K random write for 10 minutes to allow enough data to be generated to cause some tiering. The average for the longer test was about 900 IOPS using three workers. The same test for two minutes did not perform as well.

When testing was given an opportunity to spread data around the array and write for a longer period of time the Drobo seemed to perform much better than it did over shorter test cycles.

Some discrepancy

The testing conditions I used were not completely pristine as there are other devices and things occurring on the network I was using to test, which could have affected the testing performance somewhat. I imagine that having a network consisting only of the items being tested and the systems performing the tests, would have improved the results. Given the additional traffic in the environment I tested the unit in, I think performance was consistent, but under more pristine conditions I think the results might have been significantly better.primary storage for up to 250 users or as Tier 2 storage and backup for departments in larger organizations

I found the B1200i to be very easy to configure and the performance of the device to be very usable. I am not sure what the sweet spot in terms of user connections and threads would be for this device — maybe 25-50 users, depending on the configuration. NOTE: Drobo recommends the B1200i SSD as “primary storage for up to 250 users or as Tier 2 storage and backup for departments in larger organizations.”

Adding more SSDs or balancing these disks out to even the load between storage and cache might improve performance, but the type of performance benefit needed still depends on the workloads being stored on the Drobo.

Any order, just add disks

One of the other things I found to be interesting is that Drobo doesn’t care about the order of any disks within the unit. To test this theory, I removed the disk in the fifth slot and waited for the unit to come back to ready (pulling live disks when they aren’t actually failed causes a bit of turbulence). Then I pulled out the disk in the third slot, which was an SSD. With both of these disks out, I swapped them by placing the SSD in slot 5 and the SATA disk in slot 3. It took a minute or so for the drives to be recognized by the array, but shortly after that, the green lights were back on and things worked as normal.

The bottom line

I would consider the 1200i as a primary storage target, but would need to take into consideration how the network users in my environment used storage.  If the primary goal is data storage the Drobo seems to be a great choice, however if the goal is to run multiple application heavy VMs on the array, there might be challenges getting all of the work loads to function at the desired performance level. I think balancing the capacity of the unit with the performance of SSD media could help for situations like this.

I think the Drobo 1200i would also make a great backup target.  There is lots of storage available for very little rack space and the multi-pathing support will certainly be a benefit there.

Having used both the B1200i and the B800i I think that Drobo has great products for businesses and can continue to grow in the SMB/SMB+ space with this offering.