Data protection in progress... 23 minutes left ?


I just installed my brand new Drobo with:
1x Western Digital WEAD Green 2.0 Tb
3x Western Digital WEAD Green 1.5 Tb

The second drive (1.5 TB) just failed.
I’ve copied 160GB of file yesterday, and today all seemed to word well in the morning, but when resuming from sleep, the drobo woke up, and the drive #2 failed when I tried to access my data.

So I’ve rebooted to be able to access the dashboard (because he was unable to detect the drobo), and now I see:
Data protection in progress, 23 minutes left, and a progress bar.

I’ve read the manual, but I can’t figure out what it really mean ?
Before, I was using a RAID-5. If a raid-5 goes degraded, you can still access your date with 3 drive out of 4. In 23 minutes, will my data be available or will I lose everything ?

You data should already (still) be available. Drobo is telling you that your data is not protected from an additional drive failure.

After data protection is complete, your data will again be fault-tolerant and protected from a drive failure.

In other words…

  1. You should be able to access your data.
  2. If a drive fails before data protection completes, then your data will be lost, unless you are using Dual Disk Redundancy.

one of your four drives failed… so your data is safe, but has no redundancy

what drobo is now doing is rebuilding from a 4 disk array into a 3 disk array - so not only will all of your data be safe, but you will again be protected from a drive failure -

conceptually it went:

4 disk raid 5
degraded 4 disk raid 5
then its rebuilding into …
fully operational 3 disk raid 5

so you can remove the drive in red anyway,

it can only do this is you have enough free space, but its re-creating all the missing paraity / data onto the remaining 3 disks. (which i woudl imagine it has finished doing by now)

so you can just leave it as a 3 disk array - and when you need additional space, you can add a 4th drive back into your array

“but you will again be protected from a drive failure”

So now that my 3 drives are Green what will happen if I have a second drive failure, going from 3 drive to 2 ? (considering that actually I only have 160Gb of data with 1.5 TB Drive)

Thanks for the technical explaination, I like that :slight_smile:

exactly the same, if there is room it will automatically rebuild back to a safe state on the remaining 2 drives.

if you had more data (i.e. didnt have enough free space to rebuild the missing information) it would simply ask you to replace the failed drive so it had something to rebuild onto

So, as long as I have at least 2 disks that are solid Green, the system can handle to lose one disk without loosing data ?

yes, solid green means you are protected against a disk failure.

flashing yellow/green means are you not protected and it is rebuilding to a safe state (and it tells you in dashboard not to remove any disks)