[quote=“bhiga, post:8, topic:646”]…
Seems like another drive failed during the relayout process.
If that’s the case, I’m sorry to say, but your data is gone.
While relayout is in process, you data is not protected (unless you have DroboPro in Dual-Drive Redundancy mode). [/quote]
My understanding of fraumanu’s problem is that the new bigger drive failed, one of the 3 older drives failed during relayout, but the original replaced drive was OK when previously in Drobo.
Thus my reading of the situation was that, assuming he did not write anything new on the Drobo during relayout, the original data files would still be present on the 2 OK drives in Drobo, plus the removed OK drive.
If Drobo software was clever enough, putting back in Drobo the 3 original OK drives should thus allow a rebuilt of the 4th defective one, right ?
Why do you think this is not the case and the data is lost ? Does Drobo relayout continuously destroys the original directory as soon as it starts ?
It is really a pity DRI does not communicate on what errors are recoverable during relayout and what are not; for instance, it is not clear at all to me if there is some reliability benefit to put the Drobo off-line during relayout or not.
Actually, I am close to thinking DRI made a design error : even the base Drobo should have 5 disks slots, including 1 always free during normal operations. This slot would be used only for inserting a new disk during relayout. The removal of the disk to be replaced by the new one would be done ONLY after relayout is notified as successful, thus avoiding 1 week or more of non-protected data (furthermore during the most stressful activity period).
For sure, you get the same benefit from Drobo Pro, but the price point is totally different and largely inadequate for individual users. 4 disks Drobo was right where it should be, which made its success, except that relayout failures are frightening and seem to be far from exceptional, considering the number of forums entries on the subject, although some had happier ends.
On the other hand, DRI could probably achieve the exact same benefit with different, more optimized relayout software, offering the option of “safer relayout” by forcing a lengthy relayout to proceed off-line, thus freezing the data on all original disks and allowing to go back to the original situation (putting back in the removed disk).
That obviously would assume a checkpoint taken at the beginning of the relayout and no data files moved during relayout on the 3 untouched disks.
Alternatively, keeping Drobo on-line and forsaking data protection only for data newly written or modified during the relayout period (while keeping it for the data present at the beginning of the relayout and not modified during it) would be acceptable to me.
I truly believe DRI needs to make a major effort on its relayout software, since the conjunction of extremely lengthy relayout (2 weeks for 4 x 2TB upgrades !!) and non-protected data and non-recoverable errors during that lengthy period is frightening enough to destroy the confidence most of us had in Drobo data safety : if I have to go back to mirroring, the economic benefit of the Drobo (1/4 the cost of storage mirroring) becomes zilch.