pro 6 fails to expand volume

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 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.

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!

Even though expansion failed, if frontview says the volume is protected, then it should be able to survive a disk failure. Though of course backups are still needed.

If you do the factory default with 5x3TB installed then you shouldn't run into this limit when you add the 6th disk. If you are planning to use single redundancy, you could also do the default with 6x3TB installed.

For dual redundancy, it is simpler to start with 5x3TB (single redundancy) and then add the last disk for redundancy.

I can't find it in the frontview, but I guess the volume is protected - all lights are green everywhere (I have single redundancy).

I think while making a factory default I can even start the volume with 4 discs and have 2 spare discs for backing up more data (the most crucial data is already protected with two copies in different places, of course :D ). Do you think that would be a smart idea? By adding 2 discs to the initial volume of 4 discs I shouldn't hit the limit of 8 TB anyway. I'm planning to stay on single redundancy.

Thanks for the advice!

Look on the volume settings page ("status: redundant")

You can of course start with 4x3TB drives if that will hold your data comfortably. If you exceed 80% capacity, it is a good idea to add another disk.

The status is redundant. As I undestand that means "so far so good" :D

I already have 10,5 TB of data so all limits have long been exceeded :D It seems that I should create a 4 discs volume first, add data until I hit 80% of overall capacity, then add 2 discs more one after another and enjoy the thing :D

Sounds like the right recipe.