My Cloud EX2 Ultra no longer seen on Big Sur 11.2.2 after Firmware Update 5.10.122



After updating my EX2 Ultra to firmware 5.10.12, Mac OS 11.2.2 no longer connects to the drive.

Steps taken to reproduce:

  1. Attempted reset (both short, 4 seconds, and long, 40 seconds) - issue persists
  2. Attempted both direct connection and connection via WLAN router - issue persists
  3. Restarted computer, issue persists, even in safe boot
  4. NAS drive also not seen from iOS

Suggested remedy:

Repair or replace

What other steps should I be trying?


If you haven’t done so already you may want to see the various discussions in the OS5 EX Series subforum (where there is discussion about the OS5 EX2 Ultra) about Big Sur issues to see if there are any solutions to your issue.

More discussions on Big Sur issues on the EX2 Ultra in the OS3 subforum for the EX2 series of devices.

After some online research, I learnt enough that an “arp -a” command in terminal will list all my attached derives, and that is the IP of my drive (it even knows what it is).

When attempting to connect to it vis browser or cmd-k in the finder, I get nowhere.

Now that “Network Utility” is replaced by using terminal, I have no idea how to attempt to ping the device as my knowledge of UNIX is too small (but I suspect Pinging it would work).

After some time on the linked forums, I don’t think I found an answer to my question (or if I did, it wasn’t written in way I recognised).

Next step would be the helpline, right?

Update: Ping to host: “server down” (no response) “no route to host” (direct Ethernet connection)

Update, part 1 of 2

In tidying my office, I had to unplug all my cables and move stuff around.

After several hours I plugged everything in, and the NAS was visible again!

Update 2 of 2:

This lasted for a few days only. It seems putting my computer to sleep during Time Machine Backups makes the drive have an identity crisis.

This time turning off the power does not help.

Question: Big Sur + MyCloudEX2Ultra + Sleeping … what should I be doing?

In fact it seems to have a lot to do with whether I attach a USB drive or not