Host I/O 109If the enclosure does not initializeIt may take up to two minutes for all enclosures to initialize. If an enclosure does not initialize:• Perform a rescan• Power cycle the system• Make sure the power cord is properly connected, and check the power source to which it is connected• Check the event log for errorsCorrecting enclosure IDsWhen installing a system with drive enclosures attached, the enclosure IDs might not agree with the physicalcabling order. This is because the controller might have been previously attached to enclosures in a differentconfiguration, and it attempts to preserve the previous enclosure IDs, if possible. To correct this condition, makesure that both controllers are up, and perform a rescan using the SMC or the CLI. This will reorder the enclosures,but can take up to two minutes for the enclosure IDs to be corrected.To perform a rescan using the CLI, type the following command:rescanTo perform a rescan using the SMC:1. Verify that both controllers are operating normally.2. Do one of the following: Point to the System tab and select Rescan Disk Channels. In the System topic, select Action > Rescan Disk Channels.3. Click Rescan.Host I/OWhen troubleshooting disk drive and connectivity faults, stop I/O to the affected disk groups from all hosts as adata protection precaution. As an additional data protection precaution, it is helpful to conduct regularly scheduledbackups of your data. See also “Stopping I/O” (page 128).Dealing with hardware faultsEnsure that you have obtained a replacement module of the same type before removing any faulty module asdescribed in “Module removal and replacement” (page 116).IMPORTANT: If the enclosure system is powered up and you remove any module, replace it immediately. If thesystem is used with any modules missing for more than a few seconds, the enclosure(s) can overheat, causingpower failure and potential data loss. Such action can invalidate the product warranty.IMPORTANT: Observe applicable/conventional ESD precautions when handling modules and components, asdescribed in “ESD precautions” (page 116). Avoid contact with midplane components, module connectors, leads,pins, and exposed circuitry.
