I have a 500Gb hard drive with 20 bad sectors according to gnome-disk, and when I try to run a SMART self-test, it fails at reading. But gnome-disk shows that every other SMART attribute is OK, and this SMART failure doesn't kick in my motherboard's UEFI SMART failure warning on boot.

Is the hard drive unreliable? Can I still use it safely? Is there anything I can do to fix it or prevent failure?

  • Please edit question with output of smartctl /dev/sda -A as root, so we can actually see the SMART attributes (instead of having to guess) and explain to you what they mean. But if you already have 20 bad sectors, and the SMART self-test encountered a 21st bad sector, it's definitely time to make a backup, and the drive is very likely on its way out.
    – dirkt
    May 3, 2017 at 6:39

1 Answer 1


You should replace your hard drive if you value your data.

SMART in consumer hardware grade is usually not very useful and the firmware mostly reports everything is OK; usually in business/server grade hardware it is more informative.

Bad sectors also usually are masked internally by the hard drive up to a point. By the time they start showing up/being visible to the outside, it is time to dump the media/hard drive and replace it with a new one.

See Google Says Diagnostics Don't Catch Many PC Drive Failures

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