What should I do if medium errors occur?
Applicable Products
QTS, QuTS hero
Root Cause
If you see the following message in the System Even Log, your system may have encountered medium errors.
[Hardware Status] Disk X: Medium error.
This error occurs when the system cannot successfully access the data on your device. We can detect medium errors by verifying data with a checksum, which is a value used to detect errors introduced during data transmission or storage. Checksum mismatch is usually caused by data corruption, also known as bad blocks, often due to long-time use of devices and disks.
Medium errors can be either temporary or permanent. Your devices sometimes can recover from medium errors. One of the common consequences of medium errors is longer I/O latency, which occurs because your device is attempting to recover from these errors.
Solution
Follow these steps to identify and resolve this issue.
- Go to Storage & Snapshots > Storage > Disk/VJBOD.
- Select a disk.
- Click Disk Health.
- Check disk health summary and S.M.A.R.T. information.TipS.M.A.R.T. attributes are indicators for predicting disk health. You may see Warning or Error if some S.M.A.R.T. attributes reach the thresholds defined by disk manufacturers or QNAP.
- Go to Test and then run a S.M.A.R.T. test.
Sometimes you can swap disks in their drive bays to work around medium errors, but if these issues persist, you may have bad blocks on your disks and need to replace them.
If the status of a disk has turned into Warning in S.M.A.R.T. disk information, we recommend replacing the disk soon, as it may fail in the near future. If the status of a disk has turned into Error, it must be replaced immediately. You can click Raid Group to find the RAID group to which an abnormal or faulty disk belongs and identify its RAID type.
