My Cloud EX2 Ultra – Drive 1 Shows “Bad/Fault” Despite Passing Diagnostics

[omar2]

I have a WD My Cloud EX2 Ultra with two 4 TB drives configured as RAID 1.

The RAID volume currently shows Healthy/Good, but under Storage → Disk Status, Drive 1 shows Bad, while Drive 2 shows Good. The Diagnostics screen also reports Drive Status: Fault.

I have already performed the following tests:

• RAID 1 status: Healthy
• RAID Volume_1 status: Good
• Auto-Rebuild: ON
• Quick Disk Test:
  • Disk 1: Passed
  • Disk 2: Passed
• Scan Disk / Volume scan: Completed successfully, no errors found
• SMART data does not appear to show an obvious failure.
• Drive temperatures are approximately 46–47°C.
• Fan is operating and was recently showing approximately 4100 RPM.
• System temperature shows Normal.

Some of the SMART values for Drive 1 include:

• Reallocated Sector Count: Current 200 / Threshold 140
• Reallocated Event Count: 200
• Current Pending Sector: 200
• Offline Uncorrectable: 100
• UDMA CRC Error Count: 200

Despite all tests passing, the NAS continues to report:

Drive 1: Bad
Drive Status: Fault

I would like to determine whether this is an actual physical drive failure, a SMART/firmware reporting issue, or a stale system alert before replacing the drive or rebuilding the RAID.

Could you please advise:

1. Why Drive 1 is being marked as Bad even though the diagnostic tests pass?
2. Is there a specific SMART attribute or system log I should check?
3. Should I replace Drive 1, or is there a way to clear/reset the drive health status safely?
4. Is there any firmware-related issue that can cause this behavior?

Device: WD My Cloud EX2 Ultra
Configuration: 2 × 4 TB, RAID 1

[DavsC2]

I have a WD My Cloud EX2 Ultra with a 4TB and 10TB configured as separate JBOD Volumes and from circa July 26 Have had identical issues as you have. I wonder whether it is something to do with the March firmware update? Drive 1 still runs fine so I have backed up important stuff and am hoping that the glitch sorts itself out!