Learn About the Background Media Scan Process

A media scan is a background process that runs on all in the for which it has been enabled, providing error detection on the physical disk media. Enabling the media scan process lets the process find media errors before they disrupt normal physical disk reads and writes. The media scan process scans all virtual disk data to verify that it can be accessed, and, optionally, scans the virtual disk data.

Note: The media scan must be enabled for the entire storage array and enabled on each virtual disk within the storage array. You can enable and set the duration over which the media scan runs by selecting Storage Array >> Change >> Media Scan Settings and Virtual Disk >> Change >> Media Scan Settings.

A media scan discovers the following errors and reports them to the :

Error

Description/Result

Unrecovered media error

The data could not be read on its first attempt, or on any subsequent retries.

Virtual Disks with redundancy protection. Data is reconstructed, rewritten to the physical disk, and verified. The error is reported to the event log.

On virtual disks without redundancy protection ( virtual disks and degraded , , and virtual disks), the error is not corrected but is reported to the event log.

Recovered media error

The physical disk could not read the requested data on its first attempt, but succeeded on a subsequent attempt.

The data is rewritten to the physical disk and verified. The error is reported to the event log.

Redundancy mismatches

Redundancy errors are found.

The first 10 redundancy mismatches found on a virtual disk are reported to the event log.

Note: The media scan checks for redundancy only if the optional redundancy checkbox is enabled.

Unfixable error

The data could not be read, and consistency or redundancy information could not be used to regenerate it. For example, redundancy information cannot be used to reconstruct data on a degraded virtual disk.

The error is reported to the event log.

Error	Description/Result
Unrecovered media error	The data could not be read on its first attempt, or on any subsequent retries. Virtual Disks with redundancy protection. Data is reconstructed, rewritten to the physical disk, and verified. The error is reported to the event log. On virtual disks without redundancy protection ( virtual disks and degraded , , and virtual disks), the error is not corrected but is reported to the event log.
Recovered media error	The physical disk could not read the requested data on its first attempt, but succeeded on a subsequent attempt. The data is rewritten to the physical disk and verified. The error is reported to the event log.
Redundancy mismatches	Redundancy errors are found. The first 10 redundancy mismatches found on a virtual disk are reported to the event log. Note: The media scan checks for redundancy only if the optional redundancy checkbox is enabled.
Unfixable error	The data could not be read, and consistency or redundancy information could not be used to regenerate it. For example, redundancy information cannot be used to reconstruct data on a degraded virtual disk. The error is reported to the event log.

Learn About the Background Media Scan Process

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