Yes I heard back from tech support. They had me send my config files to engineering to figure it out.
The source of my problems is OS5 does not support any drives larger than 8TB. I have 2 x 10TB drives - these were recognized in OS3 but are no longer supported on OS5. Their reasoning is that the largest MyCloud Mirror SKU they sell is 2 x 8TB and they don’t need to support drives larger than that.
Any NAS solution on the market should allow for user-upgradability. I could write more about how shortsighted this seems, but yeah this is as bad as it sounds.
OS5 only supports up to 2 x 8TB. Proceeding with the firmware upgrade is catastrophic. Perhaps there should be a check by the firmware updater that verifies that the drives will work in OS5 before proceeding but what do I know.
Upgrading the drives on a NAS doesn’t seem like a wild expectation from a user’s perspective. Locking the user in to storage sizes that WD deems acceptable (ie: the original storage capacity)… I’m not sure what they expect users like me to do - go buy 2 x 8TB drives so I can downgrade my storage capacity? I do not find this acceptable.
Tech support proposed to ship my MyCloudMirror back to them and they would ship it back to me with OS3 installed. That way it would again support my 10TB drives. It was a generous offer, especially being about a year outside my warranty period. You might even say this is the right thing to do, but really it’s a situation created by WD.
So I bought a Synology NAS, and I’m enjoying that way more than I ever did the MyCloudMirror. I’m moving on from WD.
Needless to say the data that was on my drives was not readable on my new Synology NAS. I’m sure I could have hacked my way through command lines to make it work, but fortunately I had a sort-of recent backup. Always have a backup.
If I had taken WD up on their offer for the OS3 replacement, would I have been able to plug my drives in there and get access to the data on my drives? I never asked tech support because I was still beyond livid that their OS5 upgrade had essentially bricked my NAS in its current configuration. Unless I went out and bought smaller drives 8TB drives. Ridiculous.
Wish you luck. Tech support takes about 1 day to send out 1 reply (I’m sure they are also stretched thin due to the pandemic). Perhaps there is hope if you exported your OS3 config before you did the OS5 upgrade. Maybe the OS5 updater automatically makes a backup of the OS3 config. Probably not since there is no downgrade path once have OS5.