pro 6 fails to expand volume

StephenB wrote:

There is a limit on volume growth of 8 TiB from your starting point. Since you started with a single disk, that would be 2.7 TiB (3 TB). So you can't expand above 10.7 TIB. The cleanest "solution" is to back up your data and configuration, do a factory default, and then restore everything. There are also some instructions on the forum on doing an "off line" expansion http://www.readynas.com/forum/viewtopic.php?f=66&t=62916&p=353102#p353102 This will overcome the growth limit, although as Chirpa notes in the thread you can't use this procedure to expand over 16 TiB.

I've encountered exactly the same problem (NAS 6 Pro Ultra, Seagate 3TB drives, after having added disc 5 I got "volume expansion failed" message though NAS is working fine, and I have 10,6 TB overall capacity). Now I fully understand this 8TB volume growth limit issue. The question is: how safe is my current volume protected? What I mean is: say one of my current 5 discs fails, I replace it with a new one - would I keep all my data just fine or would syncrhonization probably fail thus corrupting the entire volume? Asking just to be on the safe side how serious for the data that "volume expansion failed" mistake is. P.S. I'm planning to perform the clean "solution" by backing up the data and restoring the factory default with 5 discs, expanding the volume with a sixth disc afterwards. Would that do?..

Thanks!