LLSC Recovery Help
Statistics Overview and Use
The ServerNet PCI Adapter (SPA) is typically one of several cards on the
host node's PCI bus. When the link layer self-check (LLSC) statistics indicate
a significant number of SAIL ASIC self checks have occurred (SPA is having
to wait too long to acquire the PCI bus), cluster communications performance
for the node may suffer significantly and (in some cases) the node may
be removed from the cluster. In this case, consideration should be given
to moving the SPA to a higher priority PCI slot in the node.
NOTE: A SAIL ASIC self check refers to the process whereby the
ASIC detects a problem serious enough to warrant aborting its normal operation.
The LLSC and recovery statistics are cleared to zero for a given SPA
when the associated node is booted. In addition, the LLSC Recovery view
can be used by those with root permission to reset the LLSC and recovery
statistics for any SPA in the cluster.
Statistics Description
The SAIL ASIC self-check recovery process performed by the SPAD (SPA driver)
saves the SAIL registers, resets the SPA, restores the SAIL registers,
and restarts the SPA. The following statistics are maintained for this
self check and recovery process:
-
Minimum Recovery Time - Least amount of time (in milliseconds) it
took the SPAD to perform one recovery cycle.
-
Maximum Recovery Time - Maximum amount of time (in milliseconds) it
took the SPAD to perform one recovery cycle.
-
Total Recovery Time - Sum total of the time (in milliseconds) the
SPAD has spent performing recovery cycles.
-
Recoveries Done in Interrupt Mode - A count of recovery cycles performed
while the SPAD was processing a SPA interrupt.
-
Recoveries Done in Poll Mode - A count of recovery cycles performed
while the SPAD was not processing SPA interrupts.
-
SAIL Link Layer Self Checks - The number of times the SAIL ASIC
has self checked due to link layer errors (PCI bus timeout).
-
SAIL Transmit Buffer Self Checks - The number of times the SAIL
ASIC has self checked due to faults in the ServerNet SAN port transmit buffer
logic.
Viewing Statistics
The statistics are displayed in one pane labeled For SPA N (where
N is the SPA number). Associated with the pane is a SPA choice box
used to select the SPA for which the LLSC and recovery statistics are retrieved.
Procedure
Select the SPA number with the SPA choice box; the statistics for the selected
SPA are displayed.
Resetting Statistics
To reset all LLSC and recovery statistics for the selected SPA, click on
the Reset button (available only to users with root permission).