Disappearing free space

I’ve been a Gen 2 user for several years and recently got a 5D for a gift. I added drives and started filling it up by moving data from the Gen 2 to the 5D. Then the 5D got into a reboot loop. I’ve been working with Drobo support on this issue for two weeks. They seem to be extremely slow, and I typically get only one instruction per day. For instance, they will ask that I put the Drobo into RO mode and then send them a diagnostic file, then a couple of days later they will send me the next step. Anyway, I digress.

The Drobo is up an running now and appears healthy. One drive is asking to be replaced but I’m waiting to hear back from Drobo after submitting my latest diagnostic report as to whether I can replace the drive. I’ve let the Drobo run, since their procedures do not tell me otherwise.

My issue is this…since this morning, the free space on the Drobos is dropping, according to the Dashboard. I’ve even copied stuff from the Drobo and deleted it from the Drobo to free more space, which it reflects, but then starts eating that newly created free space. For instance, at 3:45 this afternoon, there was 89.94GB free on the Drobo. Less than two hours later there is 36.36GB free. And dwindling. The Finder is not writing anything to the Drobo and Time Machine is not on.

Anyone know why my free space would continue to drop? Silly me, I didn’t note whether the used space was also increasing, so I can’t tell if phantom files are being written to the unit, or whether this is just the Drobo software continuing to spread things out across the drives.

Did you do any large deletions recently, or make any large changes in the capacity on the Drobo? What are the drive bay lights doing, if they are all green I doubt the unit is in relayout mode when the unit will spread out the data across all drives. Is this 5D connected through usb 3.0 or thunderbolt on your MAC? What version OSX are you running on this unit? How many drives do you have total and is dual disk redundancy in use?

I realize this post is a little more than a month old, but I just got the Drobo 5D and I am seeing a similar issue on my Drobo. I have it connected to my Mac Mini, which is running the latest OS OSX 10.9.4, via thunderbolt. I currently have 2 4TB drives in it for a total capacity of 3.6 TB in RAID. I started backing up some files last night (a total of ~200GB of Data) and this morning I woke up to the Drobo complaining that it was completely full! After stopping the backup (which never finished) and waiting a while the Drobo Dashboard refreshed and figured out that the Drobo actually still had 98% capacity.

Now, some time later, I have started my backup again and I am watching as the Drobo’s Capacity is being filled up at a much higher rate than is possible. Since I started writing this post, the drive has gone from a reported 1.3TB to 2.15TB full. Again, I am not actually transferring anywhere near that much data to it.

I am sharing the Drobo’s drive on my Mac, and I am backing up files to it over my network (GigE the whole way) from a Windows Laptop.

Any Thoughts?

did you attempt to clear the trash bin?

As an update, I have found that my space only “disappears” while I am transferring files to my Drobo. After the transfer is completed (or stopped), the Drobo realizes that I have not actually transferred as much data as it thought I did and returns the capacity reading to something rational. I have mapped this behavior and it looks like the more data that is transferred at once the larger the difference is between actually transferred size and shown transfer size, at least up to a point.

maybe it is part of a failsafe feature, so in case of a burst transfer, it acts as though the highest rate of data over the time was taking up space, to prevent it from over filling very quickly?