Drobo

new Firmware - 12562 hours for relay-out

I just updated my DroboPro - it had dual disk redundancy - I then added 2x3TB drives - now it is stating over 12.5 thousand hours of relay-out are ahead of me! Can that be true?

im confused

you say you ADDED two drives - that would not cause a relayout

what did you actually do?[hr]
Clarification: it would cause a RELAYOUT - but drobo does that internally and silently without telling you about it, you wouldnt know it was going on.

i assume you are saying that the REBUILD will take that long.

and adding drives does not cause a rebuild

Hummme, that sparked my curiosity and will give that a try over this weekend on my Elite. Hope it’s not caused by the way the 3TB geometry difference of 2TB and neccesitate the complete rebuild. If yes, then we have a serious issue.
Btw, which manufacturer drive you are using? WD, ST or Hitachi?

@docchris: - I “added” - I had 2x2TB & 6 x 1 TB - I now pulled out two 1TB drives and replaced them with 2x3TB drives.
It says, in Drobo Dashboard: “Data Protection is in progress”. So maybe that is a rebuild - but it would seem strange - I removed two drives, nothing blinked - 6 drives were solid green, two bays were empty. I added the two new drives and the “data protection” thing began.

@rambo: - I am using 7 WD drives and one hitachi (1TB)

update: the data protection timeframe has gone down to 14 hours now, which seems more realistic.

hang on - you had dual disk data protections - and then you removed TWO disks???

thats a really silly thing to do - that means you would not have been protected against a disk failure !

the whole reason to choose dual disk redundancy is so that you can remove/fail NOE disk - and still be protected against a second disk failing.

if you remove/fail BOTH disks - if one more fails - then you have lost everything!

so at the moment you have failed two of your disks - and now its rebuilding that missing data onto your two new disks… while that is rebuilding your data is VERY vulnerable - which defeats the point of having a drobo.

(there are some exceptions to this rule - if your drobo is very very nearly empty it can probably survive multiple disk failures just due to the way it protects your data - but for most people’s usage models where they have a reasonable amount of data on it - then what i put above is correct)

that also explains why the rebuild would take longer than normal - since you removed two disks - its having to regenerate two lots of parity - and assuming that drobo’s internal calculations work similarly to RAID 6 (which it pretty much has to) rebuilding from the second lot of parity is significantly slower than rebuiling from the first lot of parity.

The DroboPro should only have one drive removed at a time.

Take out one of the 1TB drives and replace it with a 3TB, let the DroboPro rebuild the data, then repeat.

Unfortunately there is nothing you can do now but wait and hope that everything is fine once the rebuild completes.

that is what I am intending to do - I don’t see how things shouldn’t “be fine” though - as I can access my data even now - I can hardly imagine that it will disappear during the rebuilding - but who knows :wink: Here’s to hoping for the best! There’s another 3TB drive waiting to be inserted, hehe.

@docchris - just wanted to come back to something you wrote earlier, stating that a RELAYOUT would normally occur if I added a drive to, I’m guessing, an empty slot. This would be silent and in the background. I just added those two 1TB drives I removed to my 4-slot drobo, which was almost empty - it immediately switched to blinking lights and a progress bar stating that “data protection is in progress” - this will take 3 hours according to the dashboard.

So my question is - is “data protection” referring to a rebuild or a relayout?

Data protection Is a rebuild - it’s protecting your data either by duplication or parity - it is restoring redundancy which was lost

Relayout is something drobo does continuously anyway - really it’s the same as defrag - just optimising what data is where and on which disk - it doesn’t tell you it’s doing this[hr]
If your drobo has solid green lights and you add another disk to an empty slot, it may pause for a few seconds, then the new disk should also go immediately solid green.

There should not be any data protection in progress

It never lost any redundancy

It just needs to do sone background work to layout the data in the most optimal fashion now there is an additional drive - no need to tell the user

hmm, still wondering why the 4 bay drobo had blinking lights for 3 hours. Anyway, thanks for clarifying the terminology!