Use this MAP to resolve an incorrect or incomplete multipath
connection problem.
Use this MAP to resolve the following problems:
- Configuration error, incorrect multipath connection (SRN nnnn –
4030)
- Configuration error, incomplete multipath connection between controller
and enclosure detected (SRN nnnn – 4040)
The possible causes are:
- Incorrect cabling to device enclosure.
Note: Pay special attention
to the requirement that a YI-cable must be routed along the right
side of the rack frame (as viewed from the rear) when connecting to
a disk expansion unit. Review the device enclosure cabling and correct
the cabling as required. To see example device configurations with
SAS cabling, see
Serial attached
SCSI cable planning.
- A failed connection caused by a failing component in the SAS fabric
between, and including, the controller and device enclosure.
Considerations:
- Remove power from the system before connecting and disconnecting
cables or devices, as appropriate, to prevent hardware damage or erroneous
diagnostic results.
- Some systems have SAS and PCI-X or PCIe bus interface logic integrated
onto the system boards and use a pluggable RAID enablement card (a
non-PCI form factor card) for these integrated buses. See the
feature comparison tables for PCIe and PCI-X cards. For these
configurations, replacement of the RAID enablement card is unlikely
to solve a SAS-related problem because the SAS interface logic is
on the system board.
- Some systems have the disk enclosure or removable media enclosure
integrated in the system with no cables. For these configurations
the SAS connections are integrated onto the system boards, and a failed
connection can be the result of a failed system board or integrated
device enclosure.
- When using SAS adapters in either an HA two-system RAID or HA
single-system RAID configuration, ensure that the actions taken in
this MAP are against the primary adapter and not the secondary adapter.
- An adapter reset might occur during the system verification step
of this procedure. To avoid potential data loss, reconstruct any degraded
disk arrays if possible, before performing system verification.
Attention: Obtain assistance from your Hardware Service
Support organization before you replace RAID adapters when SAS fabric
problems exist. Because the adapter might contain nonvolatile write
cache data and configuration data for the attached disk arrays, additional
problems can be created by replacing an adapter when SAS fabric problems
exist. Appropriate service procedures must be followed when replacing
the cache RAID - dual IOA enablement card (for example, FC5662) because
removal of this card can cause data loss if incorrectly performed
and can also result in a nondual storage IOA (non-HA) mode of operation.
Step 4044-2
Review the device
enclosure cabling and correct the cabling as required. To see example
device configurations with SAS cabling, see "Serial attached SCSI cable planning.
Step 4044-3
Run diagnostics
in system verification mode on the adapter to rediscover the devices
and connections.
- Start Diagnostics and select Task Selection on
the Function Selection display.
- Select Run Diagnostics.
- Select the adapter resource.
- Select System Verification.
Step 4044-4
The SRN is nnnn-4040.
Determine
if a problem still exists for the adapter that logged this error by
examining the SAS connections as follows:
- Start the IBM® SAS Disk Array
Manager.
- Start Diagnostics and select Task Selection on
the Function Selection display.
- Select RAID Array Manager.
- Select IBM SAS Disk Array Manager.
- Select Diagnostics and Recovery Options.
- Select Show SAS Controller Physical Resources.
- Select Show Fabric Path Graphical View.
Do all expected devices appear in the list and are all paths
marked as
Operational?
- No
- Go to Step 4044-5.
- Yes
- Go to Step 4044-9.
Step 4044-5
Run diagnostics
in System Verification mode on the adapter to rediscover the devices
and connections.
- Start Diagnostics and select Task Selection on
the Function Selection display.
- Select Run Diagnostics.
- Select the adapter resource.
- Select System Verification.
Note: At this point, ignore any problems found and continue with
the next step.
Step 4044-6
Determine if
the problem still exists for the adapter that logged this error by
examining the SAS connections as follows:
- Start the IBM SAS Disk Array
Manager.
- Start Diagnostics and select Task Selection on
the Function Selection display.
- Select RAID Array Manager.
- Select IBM SAS Disk Array Manager.
- Select Diagnostics and Recovery Options.
- Select Show SAS Controller Physical Resources.
- Select Show Fabric Path Graphical View.
- Select a device with a path that is not Operational (if
one exists) to obtain additional details about the full path from
the adapter port to the device. See Viewing SAS fabric path information for
an example of how this additional detail can be used to help isolate
where in the path the problem exists.
Do all expected devices appear in the list and are all paths
marked as Operational?
- No
- Go to Step 4044-7.
- Yes
- Go to Step 4044-9.
Step 4044-8
Determine if
the problem still exists for the adapter that logged this error by
examining the SAS connections as follows:
- Start the IBM SAS Disk Array
Manager.
- Start Diagnostics and select Task Selection on
the Function Selection display.
- Select RAID Array Manager.
- Select IBM SAS Disk Array Manager.
- Select Diagnostics and Recovery Options.
- Select Show SAS Controller Physical Resources.
- Select Show Fabric Path Graphical View.
- Select a device with a path that is not Operational (if
one exists) to obtain additional details about the full path from
the adapter port to the device. See Viewing SAS fabric path information for
an example of how this additional detail can be used to help isolate
where in the path the problem exists.
Do all expected devices appear in the list and are all paths
marked as Operational?
- No
- Go to Step 4044-7.
- Yes
- Go to Step 4044-9.
Step 4044-9
When the problem
is resolved, see the removal and replacement procedures topic for
the system unit on which you are working and do the "Verifying the
repair" procedure.