Table20. Symptom-to-FRU index (continued)
Problem
indicator Component Possible cause Possible solutions
Unable to access
drives
Drives and
Fibre Channel
loop
Incorrect storage
subsystem ID
settings
Make sure that the Fibre Channel
optical cables are undamaged
and properly connected. Check
the storage subsystem ID
settings.
Note: Change the switch
position only when your storage
subsystem is powered off.
RAID controller
failure
Replace one or both RAID
controllers. Contact an IBM
technical support representative.
Drive or drives
failed
Replace failed drive or drives.
Random errors Storage
subsystem
Midplane failure Have the midplane replaced.
Contact an IBM technical support
representative.
Hard disk drive is
not visible in RAID
management
software
Several CRUs Drive or drives
failed
Replace failed drive or drives.
Fibre Channel cable
failed
Replace Fibre Channel cable.
SFP failed Replace SFP.
RAID controller
failure
Replace RAID controller.
Midplane failure Have the midplane replaced.
Contact an IBM technical support
representative.
Drive CRU has
interface problem
with the ESM or
controller.
Replace the drive CRU.
Incorrect firmware
version
Verifythat the DS5020 storage
subsystem has the correct
firmware version. Refer to
“Software and hardware
compatibility and upgrades” on
page 17.
Acontroller has
failed in addition to
the ESM failure in
the drive channel
that originates from
the functioning
controller.
Replace the failed controller and
ESM.
Chapter6. Hardware maintenance 159