Shield

The Shield function diagnoses temporary drive errors. A drive can continue to be used if it is determined to be normal. The target drive temporarily changes to diagnosis status when drive errors are detected by the Disk Drive Patrol function or error notifications.

For a drive that configures a RAID group, data is moved to a hot spare by a rebuild or redundant copy before the drive is diagnosed. For a drive that is disconnected from a RAID group, whether the drive has a permanent error or a temporary error is determined. The drive can be used again if it is determined that the drive has only a temporary error.

The target drives of the Shield function are all the drive types (NVMe SSDs, SAS SSDs, SAS disks, Nearline SAS disks, and SEDs) that are registered in the RAID groups or registered as hot spares. Note that the Shield function is not available for unused drives.

The Shield function can be enabled or disabled. This function is enabled by default.

Figure: Shield
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If copybackless is enabled, the drive is used as a hot spare. If copybackless is disabled, the drive is used as a RAID group configuration drive and copyback starts. The copybackless setting can be enabled or disabled until the drive is replaced.
Caution

  • The target drives are disconnected and then reconnected during temporary drive protection. Even though a system status error may be displayed during this period, this phenomenon is only temporary. The status returns to normal after the diagnosis is complete.

    The following phenomenon may occur during temporary drive protection.

    • The Fault LEDs (amber) on the operation panel and the drive turn on

    • An error status is displayed by the ETERNUS Web GUI and the ETERNUS CLI

      • Error or Warning is displayed as the system status

      • Error, Warning, or Maintenance is displayed as the drive status

  • Target drives of the Shield function only need to be replaced when drive reconnection fails.

    If drive reconnection fails, a drive failure error is notified as an event notification message (such as SNMP/REMCS). When drive reconnection is successful, an event notification message is not notified. To notify this message, use the event notification settings.

Note

To set the Shield function, use the subsystem parameter settings. The maintenance operation privilege is required to perform this setting. After the settings are changed, the ETERNUS DX does not need to be turned off and on again.