NV+v2 repalcing a 2TB JBOD drive with 4TB builds 2TB volume

Since each drive is a separate JBOD volume, the 8TB volume expansion limit shouldn't be coming into play, but I wonder if it is somehow.  I've not done any multi-volume experiments on a V2 unit, and only have a DuoV2 on which to do so.

Via SSH, looking at the output of cat /proc/mdstat may be helpful.  There may also be info in the downloaded logs .zip, which one of the Netgear Mods may help you decipher.

Since you have previously used drives >2TB, that shows you do have a real V2, so the 2TB drive size limit of the V1 is not in play.

If you do end up doing a factory reset to gain use of all drives, that should not affect the content of your USB drives.

When your message first appeared, it was locked against replies (at least from us mortals).  Now that it's unlocked, maybe you'll get more.

Note to Netgear mods:  The KB artical pointed to above lists hard limits for the 300, 500, and 700 series ReadyNAS that are clearly based on 4TB drives are way out of date.