Drobo: New FS set up and working, what to do with old Drobo?
Forty-eight hours on and I have transferred all my archive data from the old Drobo+Droboshare to my new Drobo FS. All has gone well and I now have 6GB of storage (3 x 2GB Western Digital Caviar Green drives¹) which should keep me going for a year at least. I am wondering what to do with the old Drobo and I am seriously considering setting it up to mirror the new FS. Bear in mind I have archive data on the Drobo that isn't backed up elsewhere, so this is my Achilles heel.
The Drobo FS protects against disk failure—if a disk fails the Drobo shows a red light and it's a simple matter to swap the dud disk for a new drive. Drobo does all the housekeeping of reallocating data to the new storage. Even if the Drobo itself fails you can take your disks (there are up to five in the unit) and simply put them into a new Drobo FS. You have to keep the disk stack together, although it doesn't matter in what order they are inserted into the new unit.
This said, it is possible to have a system failure through misuse, corruption or simple carelessness (such as powering off the Drobo without putting it into standby) which could lead to the data on the five disks becoming unrecoverable. It's unlikely, but if something can happen it's a good idea to try to make sure it doesn't prove fatal to your data.
That's why I'm looking into the possibility of mirroring the old Drobo with the new. I might as well, but I need to read some guidance papers to find out best practice.
¹ I did have a problem with one of the two Western Digital drives I ordered from Amazon. When the package arrived, both drives came without the box and packing you would expect. One had no more protection than the plastic envelope while the other was wrapped in bubble plastic. The one that had not been protected failed within half an hour of putting it into the Drobo—red light, disk failure. To make sure I connected the disk to a Mac but Disk Utility couldn't access. The drive is now back with Amazon and I got a new one—this time from a different supplier but still under the Amazon umbrella—and it came in the original WD box with full protection.