Seagate RealStor 5005 Series Hardware Installation page 67

Is the host link status/link activity LED on?
Yes – You have isolated the fault to the HBA. Replace the HBA.
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No – It is likely that the controller module needs to be replaced.
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12. Move the cable and SFP back to its original port.
Is the host link status/link activity LED on?
No – The controller module port has failed. Replace the controller module.

Yes – Monitor the connection for a period of time. It may be an intermittent problem, which can occur with
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damaged SFPs, cables, and HBAs.
Host-side connection troubleshooting featuring SAS host ports
The procedure below applies to 5005/4005 Series controller enclosures employing 12Gb SFF-8644 connectors in the HD
mini-SAS host ports used for I/O. These models do not support replication.
1. Halt all I/O to the storage system
2. Check the host activity LED.
If there is activity, halt all applications that access the storage system.
3. Check the Cache Status LED to verify that the controller cached data is flushed to the disk drives.
Solid – Cache contains data yet to be written to the disk.
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Blinking – Cache data is being written to CompactFlash.
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Flashing at 1/10 second on and 9/10 second off – Cache is being refreshed by the supercapacitor.
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Off – Cache is clean (no unwritten data).
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4. Reseat the host cable and inspect for damage.
Is the host link status LED on?
Yes – Monitor the status to ensure that there is no intermittent error present. If the fault occurs again, clean the
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connections to ensure that a dirty connector is not interfering with the data path.
No – Proceed to the next step.
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5. Move the host cable to a port with a known good link status.
This step isolates the problem to the external data path (host cable and host-side devices) or to the controller
module port.
Is the host link status LED on?
Yes – You now know that the host cable and host-side devices are functioning properly. Return the cable to the

original port. If the link status LED remains off, you have isolated the fault to the controller module port. Replace
the controller module.
No – Proceed to the next step.
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6. Verify that the switch, if any, is operating properly. If possible, test with another port.
7. Verify that the HBA is fully seated, and that the PCI slot is powered on and operational.
8. Replace the HBA with a known good HBA, or move the host side cable to a known good HBA.
Is the host link status LED on?
Yes – You have isolated the fault to the HBA. Replace the HBA.

No – It is likely that the controller module needs to be replaced.

9. Move the host cable back to its original port.
Is the host link status LED on?
No – The controller module port has failed. Replace the controller module.

Yes – Monitor the connection for a period of time. It may be an intermittent problem, which can occur with

damaged cables and HBAs.
"Stopping I/O" (page 88).
Dealing with hardware faults 67