I have been using an 8 TB My Book Duo in RAID (mirror) mode for more than a year. Yesterday I did a minor macOS update (I am running High Sierra 10.13.6). I don’t know if that’s relevant. This morning I see that my My Book Duo is not mounting. In the WD Discovery app (from the menu icon). I see the My Book Duo appear - as “My Book Duo”, as if it’s a new hard drive. No sign of my data, not even the name of the hard drive. How can this happen?
Can you manually mount your device in “Disk utility”
No, it doesn’t show up in Disk Utility even if you select “Show all Devices”. WD tech support told me my options were to reformat or to send to a data recovery service…
Do you have WD Utilities software install. Use it to see what it telling you about your device. It could be that your RAID is bad, no hard drive detect…etc… let me know what you find. Just try to power down your device and reseat the hard drives.
Yes, the WD tech people had me install WD Drive Utilities and I ran tests (Status Check, Quick Drive Test, and Complete Drive Test). It passed all three tests (green check mark). However, under “RAID management” if I go to the “RAID status” tab, there it says that the “RAID status” is “(!) Cannot Access Data”.
One more detail: on the front of the drive there is a continuously flashing orange light (a horizontal line).
that continously flashing light mean you have a bad RAID. Since your device is configure as RAID 1 (mirror). Power down the device and remove one drive (bay1) out completely and power back on. Check if you can access your data. If not able to then power down and put the drive back into bay1 and remove drive from bay2 and power on. Check if you can access your data. Normally, when you see Cannot Access Data, is because the device had a bad RAID, then some how the original good data on the hard drive is either in bay1 or bay2 hard drive was swapping. You might have did that by swapping the original good data hard drive from bay1 to bay2 or vice versa. The device is still looking for that original setting (hard drive) in the same place before it was shutdown.
It mounts the drive and I can see my files! jebusx, thank you so much.
It mounted the drive with only HD1 inserted (it did show a dialog saying “Error in RAID configuration” but still mounted the drive). Same when only HD2 was inserted. But with both inserted, it doesn’t even show the name of the drive.
Does this mean that there is some disagreement between the two HDs regarding some data? I suppose I will copy files to somewhere else.
And - how is it that WD tech support did not recommend this solution?
Anyway, I think I am closer to getting all my data back. Once again, jebusx - thank you very much.
Once you get all your data back, you can reconfigure RAID 1 (mirror) again on that device. Then copy all your data back. Like I state, the hard drive was swap somehow when RAID 1 was degraded. You can close this as solved.