Why Does the Intel® Virtual RAID on CPU (Intel® VROC) Graphical User Interface (GUI) Report Parity Errors?

We have had parity errors being reported on our Intel® VROC RAID 5 volume.

There are multiple reasons why the Intel® VROC GUI reports parity errors in a RAID volume. A parity error is the result of an irregular change to data. The following are some recommended actions to perform in order to mitigate the number of parity errors found:

• Upgrade the BIOS version of your platform. Newer BIOS versions typically include a more recent Intel® VROC pre-OS driver.
• Upgrade the Intel® VROC Windows* driver to the latest version available. Parity errors are typically seen more often in older releases of Intel® VROC (7.7 or lower). If possible, upgrade to a more recent release (7.8 or higher). Consult with your system vendor to get the latest available drivers for your platform. See more details in How to Get the Latest Intel® Virtual RAID on CPU (Intel® VROC) Driver for Windows*.
• Turn off the power management settings used on the disks so Windows* does not do any power management on them.
• Disable Windows* write caching for each disk.
• DisableTRIM functionality.
• Run the Verify & Repair process from the Intel® VROC GUI.

If parity errors are still being seen, consider replacing the affected disks. Parity errors may also point to disk failures.

The Intel® VROC GUI has the option to run a process called Verify & Repair. This process identifies any RAID metadata inconsistencies or bad data on a RAID volume. It reports the number of inconsistencies, or the number of blocks with media erros found during the data verification. These inconsistencies are automatically repaired.

When Intel® VROC runs periodic checks on the volume, errors may appear if the parity data does not match what is expected. This is not necessarily a problem. Running the Verify & Repair process will recalculate the parity of the entire volume and compare it to the parity stored in the disks. If it does not match the stored parity, the stored parity is overwritten with the newly calculated parity.