Drobo self defragging

Hello everyone.
I Just migrated my disk pack from my Drobo S to a brand new Drobo 5D. The migration seems to have gone smoothly.

But what I am noticing is that there seems to be a lot of hard drive activity. (I can hear it) but none of my HD’s are showing activity.

I also noticed that there was significant fragmentation on the drive now (I used Defraggler to analyze the drive. - I know the dangers of defragging a drobo… I learned the hard way)

Anyway to my actual question.

Should I leave the system on for a while and let it do its thing? I usually shut down for the night but I am thinking it may be wise to let it run. also is there a way to monitor Drobos progress or should I just rely upon defraggler?


Not an expert but I imagine you should just let it do its thing for a day or so. I’m sure it has some housekeeping to do with internal error checking and file maintenance.

Defraggler (and all defrag programs) is completely useless as far as drobos are concerned. There is no way for it to see how the data is laid out on the disks, and thats pretty obvious… just think, you can have a 16tb volume, and only have 3tb of drives in your drobo. so it could look like your data was a massive mess spread over 16tb, when in fact drobo had laid it out in the most efficient patten on the 3tb of drives you actually have. Drobo is both literally and figuratively a black box, there is nothing you can do to influence, or even view, the layout of data on its drives.

To over-simplify, just because drobo is reporting that your data is laid out 3,4,1,2,5,6,7. it could be written across your disks 1,2,3,4,5,6,7. Or the other way around, it could look like the data blocks are in the correct order, but in fact they coudl be stored all over the place on a drobo.

since you’ve moved to a much newer drobo, no doubt it has a better optimisation algorithm, so what it is doing now is “upgrading” your disk pack, and possibly re-laying out the data for you.

i wouldn’t be surprised if it took a week to calm down.

Thanks for that. It is nice to have someone verify what I suspected.
I learned the hard way not to defrag it. When I first started using Drobo years ago I used the large volume version of Diskeeper on it and I corrupted the volume twice before I realized my error. I am anxious to see how much faster my backups are with the new Drobo.
(Yes. I backup my whole Drobo to other HD’s and stick them in a fire safe)


I’m just confused… you keep on saying that you know defragging doesnt work

but then you expect to be able to use defraggler to monitor the level of fragmentation?

that doenst work for the same reason… that you dont actually have access to the disks!