IBM TotalStorage DS4500, User Manual

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Four indicator lights provide status information. If a mini hub fails, the interface
fault and the bypass indicator lights on the mini hub are lit and the loop good
indicator light is off. For more information about indicator lights, see “Mini-hub
indicator lights” on page 32.
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If you replace the mini hub and the SFP modules in them and still experience
problems, the DS4500 Storage Server might have defective components or
connections. Check the storage-management software for indications of other
component failures.
For more information, see “Fibre Channel connections” on page 4 and “Types of
interface ports” on page 12.
Replacing a failed mini hub
When instructed by the storage-management software, replace a mini hub. Use the
following procedure to replace either a failed host-side or drive-side mini hub.
Attention: To prevent possible data loss, do not remove cables from a mini hub
that has not failed.
Note: You must remove the fiber-optic cable from the SFP module before you can
remove the SFP module from the mini-hub port.
1. On the mini hub that has failed, remove the fiber-optic cables from the SFP
modules, as shown in Figure 51.
For proper handling of fiber-optic cables, see “Handling fiber-optic cables” on
page 5.
2. Replace the protective caps on the cables.
3. Remove the SFP modules from the mini hub as follows:
Figure 51. Removing the fiber-optic cable from the SFP module
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IBM TotalStorage DS4500 Fibre Channel Storage Server: User’s Guide