Performance problem

I have a FW800 4 bay Drobo which is giving me performance problems. It works but it is very slow to write to, and when I say slow I mean sloooowww. Copying a couple of gigabytes (which takes 10 minutes to a USB drive attached to the same Mac) takes a minimum of 2 hours. I copied 50,000 files last week and what took me about 20 minutes to another drive took 36 hours to the Drobo. It was connected via USB but I have just changed it to FW400 and I have the same problem - I don’t have FW800 on the Mac in question. Obviously I have a problem but where do I start looking ?


How big are the files? i think lots of little writes is considerably slower on drobo than large individual files.

how full is your drobo?

just for testing - could you zip those 50k files into one big archive file and try copying that - see if it goes much faster or about the same throughput?

I assume its an intel based mac?

Wow that was quick thanks.
Big or small makes no difference. Single 2Gb movie file is what I was saying took 2 hours. The 50,000 were small files. Drobo is 30% full, and yes, it’s an Intel Mac.

Do you have anything else attached to the FW chain?

USB and FW400 is about the same speed. And like @dpuett asked, anything else on daisy chained to your Drobo or any other FW devices in your FW bus?


I would recommend first running repair disk on your drobo and your mac if you have never done that.
Then trying a different cable. If possible a different computer. If you can duplicate the performance issues, then please open a support case.

I have already tried both a USB cable and FireWire - I will try another computer. I assume I can’t cause any data integrity problems by switching it to another computer ?


No issues switching computers, as long as you properly disconnect and reconnect.

I have now tried it on my MacBook and it reported zero disk space, despite the fact that when I moved it back to the original Mac it showed space as before. It also crashed my MacBook - I got the spinning beachball and no amount of force quitting released it.
Also, on the original computer it randomly comes up in Drobo Dashboard saying “No Drobo is detected” and then after a long pause it reappears. I can’t eject it either without a several minute pause. I really think I have a faulty Drobo, unless this sort of behaviour could result from a rogue disk drive ?
Anyway, I have ordered another Drobo from Amazon - even if I fix the original I have never felt comfortable only having one, given the proprietary nature of the Drobo file structure.


it sounds like a faulty drobo - open a support case

and do let us know the outcome

when you get your new drobo - updates its firmware - then with both drobos turned off transfer your whole disk pack to the new one, then start it up

I should get the new Drobo tomorrow, I’ll take stock then.


Have now got my new Drobo, swapped the drives over and just the same problem. Therefore it must be a rogue drive, that is running extremely slowly but showing up as healthy as far as Drobo is concerned. How do I go about pinpointing this - I have 3 x 1TB drives. I am reluctant to randomly swap drives since already having one suspect one, if I swap one of the good ones I could be in a very precarious position with one good, one suspect, and one unformatted.


you need to send your log files into DRI and they will tell you which one is causing the problems.

I sent them the log and they told me it was drive 2. I have replaced it with a new 1TB drive and it is currently rebuilding. Problem is it is going to take 11 hours and I want to go home with my MacBook which is attached to the Drobo. Does the operation happen locally on my Drobo and is it safe to eject it and disconnect my MacBook ?


Turn off your computer then unplug the USB/FW cable. The drobo rebuilds own it’s own CPU not the computer.

That’s what I thought, but the reason I asked the question is because earlier today (about 10 hours ago) I did just that. When I came back to it all the green lights were on but as soon as I plugged my computer in the drive lights started flashing red and it resumed its recovery process.

I should have said as well, that it doesn’t look like swapping the drive has fixed it. I know the performance will be impaired while it is rebuilding itself, but 12 hours to copy a 170MB file - I don’t think so