Technology Update: Drobo Good Bad and Ugly
I’ve had a love/hate relationship with my Drobo disk arrays ever since I got them. I have two Drobo’s, an eight disk Dobro B800i (configured with eight 2 TB drives) as my primary working array and a 5 disk Drobo S (configured with five 3 TB drives) as an offline backup. Although some glitches when setting them up, when working they are fast and have been happy. Well, mostly happy other than the >10 days it took to add more drives: see my 13-November-2011 post.
When I got back from the SAS 2012 Fall Semester voyage, I realized that my storage space was getting tight, and after the Gone to See America 2012 Road Trip/Nikonians ANPAT 12 Trip I was running out of space. The B800i drive had a message that I was >85% full, and the one of the hard drives had a yellow light indicating that it should be replaced with a higher capacity hard drive.
One of the reasons that I bought the Drobo disk arrays was that I was supposed to be able to a hot swap upgrade if I a drive went bad, or I needed to increase drive space on the disk-array. Well, the first bit of bad news I found out that if you are using a fully populated Drobo array and all of the drives are the same size, you need to upgrade with two higher capacity drives before you get access to more space. The second bit of bad news was that I got back to New Jersey just in time for Hurricane Sandy.
Since I had configured my Drobo in the default (single drive failure mode) this meant that I could only add the higher capacity drives one at a time. And each time it takes 24+ hours for the data protection to complete before adding the next drive. This gets to be a long, long process especially during Hurricane Sandy when the power kept going down. In my case the power was on and off four times over 10 days. A UPS works for a couple of hours, but not for days. As such, I ended up having to restart the data protection process several times. This was all on the Drobo B800i that was initially set up with eight 2 TB hard drives, that I wanted to upgrade to eight 3 TB hard drives.
The upgrade process on the Drobo S system populated with five 3 TB drives was more complex. In this case the system was also configured in the default mode (single drive failure). I was at the point that there was less than 10% free space, and the top drive was red – indicating that it needed to be upgraded. The availability of 4 TB hard drives is limited, but I was finally able to find some. Again, not well documented by Drobo, but you need to replace two or more drives to get more space and get back to a normal green operating space. When I replaced the “red” 3 TB drive with a 4 TB drive you have to be very patient. First it takes several minutes to indicate that the new 4 TB drive was installed, and then it takes almost half an hour to go from red to flashing green/yellow and indicate that data protection is in progress. Really bad news – 56 hours to complete data protection.
When the data completion was finally complete (less than 56 hours, but more than 36 hours), the system flashed red on the same 4 TB drive that I just replaced – indicating that the drive that I needed to replace was the drive that I just replaced. OUCH – that was the drive that I installed and waited 36+ hours for the data protection process to complete. Was the new drive bad – or was there a software/hardware problem with the Drobo S unit. Well, I took a chance (since I have 2 other on & off site copies of the data) and the unit did indicate that the data protection process was complete. I did a hot swap of the #2 hard drive with a new 4 TB drive. It took several minutes to 1) get an indication that the drive was removed; 2) many more minutes to indicate that a new 4 TB drive was installed; and after waiting for 20 minutes that the data protection process was underway (all drives flashing green and yellow). This time it indicated 69 hours to complete (dropped to 36 hours in a couple of hours). We will see in another day or two if this works.
I have been concerned about the Drobo arrays since the posts by Scott Kelby in June. As a noted Photographer, he had four Drobo disk array fail and ultimately decided on another solution for storage of his images. Right after his posts, I started getting e-mail messages from Drobo that I needed to purchase an extended warranty. Do I stay with Drobo or find a less proprietary solution? With the amount of time it has been taking me to upgrade my storage over the last couple of weeks I wonder if it is time to evaluate a Synology NAS disk array.