A media scan is a background process that runs on all logical drives in the storage subsystem for which it has been enabled, providing error detection on the drive media. Enabling the media scan process lets the process find media errors before they disrupt normal drive reads and writes. The media scan process scans all logical drive data to verify that it can be accessed, and, optionally, scans the logical drive redundancy data.
Note: The media scan must be enabled for the entire storage subsystem and enabled on each logical drive within the storage subsystem. You can enable and set the duration over which the media scan runs by selecting the Storage Subsystem >> Change >> Media Scan Settings and Logical Drive >> Change >> Media Scan Settings pull-down menu options.
A media scan discovers the following errors and reports them 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. Result: Logical Drives with redundancy protection. Data is reconstructed, rewritten to the drive, and verified. The error is reported to the event log. On logical drives without redundancy protection (RAID 0 logical drives and degraded RAID 1, 3, and 5 logical drives), the error is not corrected but is reported to the event log. |
Recovered media error |
The drive could not read the requested data on its first attempt, but succeeded on a subsequent attempt. Result: The data is rewritten to the drive and verified. The error is reported to the event log. |
Redundancy mismatches |
Redundancy errors are found and a repair is attempted. Result: The first 10 redundancy mismatches found on a logical drive 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 parity or redundancy information could not be used to regenerate it. For example, redundancy information cannot be used to reconstruct data on a degraded logical drive. Result: The error is reported to the event log. |
Changing the Storage Subsystem Media Scan Settings