How do I interpret SoftRAID health warnings?

SoftRAID monitors your drives continuously and will alert you when something needs attention. This FAQ explains what each warning means and what to do about it.

The Two Types of Warnings

SoftRAID reports two distinct categories of problems:

• SMART errors are hardware-level conditions reported by the drive itself. They are evidence of physical problems on the drive surface or drive electronics.
• I/O errors are communication failures between your Mac and a drive. They are not automatically a sign of a failing drive – the cause could be the drive, the cable, the enclosure, or a software/filesystem issue.

These require different responses, so it is important to know which type you are seeing.

SMART Warnings – What They Mean

SMART Test Failure – Replace Immediately

The drive has already failed its SMART self-test. This is not a prediction – the drive has failed. It may still be passing data, but it could stop completely at any moment. A failing drive can also cause data corruption on other drives in the same enclosure.

Action: Back up immediately. Remove the drive from your enclosure as soon as possible. Replace immediately.

Predicted to Fail – Act Urgently

SoftRAID has detected one or more SMART parameters that are strongly associated with imminent failure, even though the drive has not yet failed. Based on research across hundreds of thousands of drives, these warnings are serious and should not be ignored.

Action: Back up immediately. Order a replacement drive. Do not wait for the drive to actually fail.

Reallocated Sectors – Replace Immediately

The drive found a bad sector and moved the data to a spare sector elsewhere on the disk. Even a single reallocated sector is grounds for replacement – research shows a drive with reallocated sectors is 20-60 times more likely to fail within 60 days.

Action: Replace the drive immediately.

Failed Reallocations – Replace Immediately

The drive tried to reallocate a bad sector but could not. This means the drive is running out of spare sectors and has days or weeks before complete failure.

Action: Replace the drive immediately.

Pending Reallocations – Certify First

The drive has marked sectors for reallocation but has not yet moved the data. This may resolve itself, or may indicate a deeper problem.

Action: Certify the disk (Disk menu – Certify Disk). If certification fails or sectors become reallocated, replace the drive.

Unreliable Sectors – Certify First

The drive had to retry reading a sector. This is sometimes caused by an external event such as a power loss or bus ejection rather than a failing drive.

Action: Certify the disk. If it passes certification, it can return to service. If it fails, replace it.

SSD/NVMe: Media Wear Warning

SSDs and NVMe drives have a finite number of write cycles. SoftRAID monitors the media wear indicator and will warn you when the drive is approaching end of life.

• Media wear below 10% - Running low on spare sectors. Plan replacement.
• Media worn out - Drive is at end of life. Replace immediately.

I/O Errors – What They Mean

An I/O error means a read or write operation failed to complete. Unlike SMART errors, I/O errors do not automatically mean your drive is failing. Common causes include a failing drive, a cable or enclosure issue, a Thunderbolt bus problem, filesystem corruption, or an unexpected ejection during active use.

How to diagnose I/O errors:

• Open the SoftRAID log (Utilities menu – SoftRAID Log) and check the timestamps of the errors.
• Did all errors occur at the same time? This points to a single event – a kernel panic, power loss, or ejection – rather than an ongoing hardware failure.
• Clear the I/O error counters (Disk menu – Clear I/O Errors) and monitor for new errors over the next few days.
• If errors return repeatedly on the same disk, that disk is likely the cause. If errors appear on different disks in the same enclosure slot, suspect the enclosure. If all disks show errors simultaneously, suspect a cable, Thunderbolt bus, or filesystem issue.

If a disk shows I/O errors AND any SMART warning (reallocated sectors, predicted failure, etc.), replace that drive immediately. The combination significantly increases the likelihood of imminent failure.

Quick Reference

An Important Note About SMART

SMART is a powerful tool, but it is not perfect. Research has shown that 36% of failed drives showed no SMART warnings before failing. This is why maintaining current backups is essential regardless of what your SMART status shows.

Need Help?

If you are unsure how to interpret a warning, submit a support ticket and attach a SoftRAID Tech Support Report (Utilities menu – Generate Report for Tech Support).