I/O Errors

What is an IO error?

An IO error is a communication error. There are two main causes for IO errors:

The disk is failing. The data on the disk is damaged and the disk is unable to perform the requested read or write.

I/O Errors – one disk only in a multi disk enclosure

If a single disk in a multi-disk volume generated an IO error:

This is likely a signal that there is a problem with the disk. It is unable to reliably communicate with the host computer.

Troubleshooting:
Run the SoftRAID Application.
Clear the IO error counter (errors only)
Give the disk a SoftRAID “disk label: so you can identify the disk more easily.

If this is an external enclosure, try swapping the disk with any other disk.

Continue using the volume, until the next IO error.

Did the error happen on the same disk? (replace the disk)
Did the error happen on the same “slot”? (you may need to replace the enclosure)

I/O Errors – You have a multi disk enclosure and all disks, or more than one disk generated I/O errors.

This is more likely a problem inside the volume, such as a directory issue. The directory points to where files are located. If it is damaged and points to a location on a disk that does not exist, then your disks may generate I/O errors.

This may also occur after a kernel panic, application crash, or other software trigger.

Troubleshooting:

Run the SoftRAID Application.
Clear the IO error counter (errors only)

Run Disk Utility, “first Aid” open your volume and ensures it passes.

If you continually get I/O errors, you may need to backup/restore your data to resolve this issue.