Drobo seemingly more confused than me!

I have a very straight forward setup but for some reason my Drobo backup isn’t working the way I thought it would.

My Mac Pro has 3 internal Media drives labelled A,B,C of sizes 1TB,1TB,500GB

My Drobo has 2 x 1TB WD Green Caviar Drives

Media Drive A contains 560GB of Final Cut Pro Data and drives B & C are currently empty. Using DroboCopy I have created 3 scheduled copies to backup Media Drives A, B and C daily. For the first two days this seems to work fine but on the last backup of Media Drive A Drobo kept going and going and going and going.

I eventually aborted the copy after Drobo had written 790GB, more than 230GB above what it was meant to be copying. At this point it was also asking me to add an extra drive. After a power down I popped out the hard drives and then pushed them back in and restarted Drobo. It is now telling me it will take 18 hours to complete ‘Data Protection’.

Will this sort out the storage capacity details in Dashboard. Will it jump from 790GB down to 560GB and stop asking me to add a new drive?

It’s a frustrating introduction to Drobo - a system I believed would offer me a solid backup of my data. If anyone else has suffered this I would love to hear from you. Any help would be useful.

Many thanks

Steve

I would recommend running repair disk from disk utility on the drobo volumes.
Also could possibly be an issue with a drive. I would suggest opening case so we can take a look at those drives.