Need help identifying failing drives in EXT2 Ultra with RAID 1 and replacing it

One of the drives in my EXT2 Ultra configured as RAID 1 just failed. Luckily, it should be covered by the 3 year WD warranty (it’s a WD drive). However, I have no idea how to tell which is the drive that failed, since they’re both identical. I also don’t want to try and remove 1 at a time, because I don’t know what that would do to my RAID configuration and, ultimately, my data, which is what I am trying to save the most.

Does anyone know how to identify the drive? According to the My Cloud OS 3 software, Storage, Drive Status page, it’s Drive1. Is that the one on the left or on the right when I am facing the EXT2 Ultra?

Also, say I know which disk it is and I pull it out to get the serial number and send to WD. Should I turn the NAS back on? Will it automatically convert to RAID 0 and I won’t lose any data? And once I get the replacement disk, can I pop it in and then, turn the configuration back to RAID 1, also without losing data?


Thank you in advance.

UPDATE: After posting this, I opened the EXT2 and noticed the disks are labeled. 1 is on the left and 2 is on the right. I also came up with another idea to confirm… Through the software, I can get the serial number of the good disk. I can then pull both out and check with one has a different serial number on the back. That should be the bad one. The rest of the questions remain.

Anybody please?

If it is drive 1, open the top cover and there should be a label drive 1 and drive 2 slot

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Yes, see my update in the original post. That much I could figure out. Thanks. It’s the rest I need help with. I just want to make sure I am doing this right. I don’t want to lose my data. I’ve sent the disk in for replacement. Once I get that new one back. I plan on installing it, turning the NAS back on and I wonder if the RAID 1 will automatically be rebuilt without losing data.

If you have set the Auto Rebuild, when the unit bootup with new drive replace in the slot…it should automatic rebuild the Raid for you and you can still access your data while it rebuilding the Raid. If Auto Rebuild not set, then you can select the manual rebuild which is not hard just follow the setup.


Very helpful. Thanks a lot!