How to format drives after used in Drobo?

Not long ago I upgraded a few of the drives in my Drobo. Replaced 2x 1TB with 2x 3TB. I would like to use the 1TB drives in my workstation and one of my render nodes as a secondary drive for caching simulation data locally vs over the network. (I do 3d computer graphics and sometimes do fluid/particle simulations. These simulations will not start calculating the next step of the simulation until the cache data for the current frame has been written to disk. Saving the cache data locally during the simulation saves a great deal of time)

However when I connect the drive via SATA cable, it is totally un-accessible. I can’t mount it, format it, anything. Would appreciate any suggestions.

Lee Johnson

hi lee, can i check if that drive was replaced just for a upgrade, (and that it wasnt actually a dodgy disk that had failed and the drobo marked as bad?)

if the drive was ok, have you tried using disk management (if on windows) to see if the stand-alone, removed 1TB drive appears there? (if you can, it might be good to put the drobo in standby mode if nothing is using it, just to help prevent trying to manage the drobo in that way by mistake?)[hr]
btw, when i upgraded a wd10eads drive into a wd15eads drive, i was able to re-purpose a 1TB, (i think i had it plugged into an icydock usb caddy at the time, rather than directly by sata)

also one thing to bear in mind though, is that some usb caddy station can only recognise (or format) drives up to a certain size, and there have been some cases where a user was not able to format a larger drive for re-use, until another connection method was established.

(it’s also cool that you do vfx) :slight_smile:

I have the same problem on a Macintosh computer_ How do I reformat a 1.5TB HD for use with a Mac as a storage drive – it does not mount, nor can be seen by Disk Utility, and was previously used in a 4-Bay Drobo?

hi damian, can you remember if that drive was a good working drive (which was removed as part of an upgrade to another larger drive for example), or was that 1.5TB drive actually a failed drive that you removed from the drobo?


The drive was replaced simply for a larger one. There was nothing wrong with it. It shows up in the Windows disk management window, but I can’t do anything with it. I can’t format or anything else. Same with DOS commands.

This was a while ago, and I don’t remember the what the error messages were exactly. I’d have to pull the drive out of the closet and open up my machine to connect it to try again. I only just now thought to post the question here because I had the question about a folder I can’t delete.

thanks for the info lee, will just also link this to your other post too:
for the currently removed drive, am not sure why it would not be visible, though if you happen to have a spare machine (or the current one but without any other drives or devices attached), maybe giving it a go on dariks boot and nuke might help?

It IS visible, it’s just not accessible. Cant run a format or chkdsk or anything. I have Dariks boot and nuke on a CD. I can’t remember if I tried doing it that way or not. I don’t have a machine that doesn’t have a drive in it, but I assume that you can choose which drive to nuke when you boot from the cd via the BIOS.

ah it might offer a choice but it is probably safer to try it without any other drives attached, just in case.

btw there is another thread here that might help… it helped another user get access again to one of their 3TB drives:

That other thread sounds like it might be the ticket. After reading it, I do remember that initializing the drive was one of the issues I was running into. When I build my next workstation, I will use it to try Dariks Boot and Nuke, as well as the suggestions on that other thread. Thank you again.

thanks, please feel free to let us know how things go