What happens when 1 drive is removed from a 4 drive diskpack?

If I have 4 drives in a diskpack and Drobo reports 1 drive is missing will that ALWAYS result in a relayout - even if the missing disk is re-inserted?

“Why didn’t you insert all the drives?” I hear you ask. I did… into a replacement Drobo DRI sent me due to fan problems in my original. When I rebooted the refurb it reported 1 drive slot as empty/red light (according to the diagnostics the disk was missing) even though the disk was inserted correctly all the way in.

I shutdown the drobo and put the 4 drives back in my original unit.

Was that a mistake?? Could I have tried to reseat the drive while the drobo was still on? And if it saw the drive again would it have prevented the relayout?

I thought you could pull out any single drive from Drobo without a hitch or a rebuild??

When I put them back into my original Drobo all the drives were recognised fine but I got flashing green/amber lights and 24hr relayout. :frowning: even though the ‘missing’ disk from the pack was in place.

[I have a 2nd replacement Drobo from DRI but I am obviously hesitant to transfer my diskpack once again, not the least because the drives do not go into it as easily as my original drobo, neither do they clunk into place in a reassuring way when all the way in.]

if you put the drive back immediately and nothing much has changed with the file system, i believe it can do a quick check and then just accept the drive (this has happened to me a few times when a drive was loose) if you’ve changed the contents too much, then it will need to rebuild onto the disk.

Nothing changed at all on the disk AFAIK so I could have tried to reseat the drive. OK that’s good to know thanks.

Is it better to do this without the Drobo connected to my Mac then so there’s no chance of anything changing?

What if I still can’t get it to recognise a drive and have to shut down the drobo with only 3 disks recognised and go back to my original?

…or if you take too long to re-insert the drive, and relayout has already begun, then you’ll have to sit through the relayout to 3-drives, then the 4th drive will get added.

Doesn’t matter whether Drobo Dashboard is running or not - the relayout process runs strictly on the Drobo itself (doesn’t require a client system connected at all).

If your Drobo is in relayout and you shut it down, relayout will continue when it gets powered back up again.

So two scenarios:

  1. Relayout with only 3 drives hasn’t started yet, so reinserting the 4th drive will just do a quick check and no relayout occurs.
  2. Relayout with only 3 drives has started, so relayout continues with or without the 4th drive.

OK - so how long do you have before a relayout is initiated?

If I shutdown before a relayout occurs, swap to the original drobo with all 4 disks back in can I prevent a relayout - OR - does powering down in the ‘missing disk state’ automatically trigger a relayout on next boot up?

(I meant to not have it connected to the Mac to prevent something accessing the Drobo)

I’m just curious. What happens if I have a Drobo with a full set of 1TB drives. It will give me 3TB as available space that I occupy with 2.5TB data. What happens if one drive breaks or is removed? The Drobo can not reconfigure to using 3 drives with 2TB space, because that would destroy 0.5TB of data. Can I still use the Drobo and even write more data to it? I understand that my data would be in danger, but it is also important to keep it online.

yes, that is exactly what will happen, although it will be slower, it will just keep asking you to give it another drive to rebuild onto - but it will still be accessible during this time

I’ve done that, removed 1 drive with more than 1.8TB of data. Drobo would not let me copy any more data to the drive, said the drive was full and my data was unprotected. I could still access and copy data from it. This is what we would expect.

However, when I had less than 1.8TB of data, drobo showed the remaining space till 1.8TB as free space, even though it had not relaid the data yet.