I recently completed a scheduled parity check on my Unraid server which resulted in 18 errors. My dashboard is also now showing a red notification: "Pool has 1 SMART error" for my cache drive.

I'm in the process of running a second parity check, but I'm not sure if that's the correct process and if I should just replace the Cache drive. My electrical utility company has had random shutdowns the past few weeks, and it looks like my UPS didn't shutdown successfully either.

This is an old SSD (240GB) but I actually have a second one (1TB), but I believe it had issues years ago, and I couldn't remove it from unassigned disk devices, so I just used the old SSD (240GB) instead.

System Details & Observations:

• Parity Check Stats: Last check took 2 days, 5 hours, 26 minutes with an average speed of 93.6 MB/s.

• Cache Drive SMART Attributes:

  • Attribute 199 (UDMA CRC Error Count): Raw value is 1.

  • SSD Endurance: Remaining life is at 22%.

  • Power On Hours: 58,987 hours (approx. 6.7 years).

matrix-diagnostics-20260305-0720.zip

UDMA CRC errors are a connection issue, typically a bad SATA cable, but 1 error is no reason for concern; if it keeps increasing, replace the cable.