S.M.A.R.T. (Self-Monitoring, Analysis, and Reporting Technology) is a monitoring system built into modern hard drives, including the Western Digital Ultra star DC HC530 14TB, to detect signs of potential hardware failure. One of the more commonly flagged S.M.A.R.T. attributes is ID 187, labeled as:
"Reported Uncorrectable Errors" or sometimes "Reported UNC Errors"
What Does S.M.A.R.T. ID 187 Mean?
This attribute tracks the number of errors that were reported to the host system (like your computer or server) but couldn’t be corrected by the drive’s error correction mechanism. In simpler terms, these are read or write operations that failed and couldn’t be fixed even after retries or internal error correction.
These errors are often signs of weak or failing sectors on the hard drive platters. While a few occasional errors may not be critical (especially in enterprise drives like the HC530 which operate under high load), a rising or high value in Attribute 187 can be a red flag for potential future failure.
Should You Be Concerned?
For the Ultrastar DC HC530, a few key things to keep in mind:
Enterprise Context: This drive is designed for data centers and high-performance environments. It may log errors more aggressively for transparency.
Raw Value vs Threshold: Check the "Threshold" and "Raw Value" fields. A value that’s below the threshold isn’t immediately dangerous, but it should still be monitored closely.
Rate of Change: If the value of Attribute 187 increases over time, especially rapidly, it’s a serious warning sign.
In most cases:
A raw value of 0 = Healthy
A raw value of 1–10 = Mild concern; monitor regularly
A raw value >10 = Replace the drive soon, especially in RAID setups
What Causes Attribute 187 Errors?
Some common causes include:
Bad or marginal disk sectors
Firmware bugs
Sudden power loss
Excessive vibration or heat
Aging drive hardware
How to Monitor It
Use tools like:
smartctl (Linux/macOS):
smartctl -a /dev/sdX
CrystalDiskInfo (Windows)
Hard Disk Sentinel
WD Dashboard (for WD drives)
Look for lines like:
187 Reported_Uncorrectable_Errors 0x0032 100 100 000 Old_age Always - 0
What to Do If It Shows Errors
Backup Immediately: If you haven’t already, create a backup of critical data.
Run Full Diagnostics: Use smart ctl -t long or WD diagnostic tools to perform a full scan.
Check for Firmware Updates: Occasionally, firmware issues can cause false positives.
Replace If Needed: If you're seeing regular increases in this count, especially with other bad S.M.A.R.T. values (like reallocated or pending sectors), replace the drive.
Summary
S.M.A.R.T. Attribute 187 on the Ultra star DC HC530 14TB indicates uncorrectable errors reported to the host. While occasional entries may not be critical in enterprise drives, they should not be ignored. If the count grows or coincides with other error indicators, consider replacing the drive and always keep good backups in place.