6100 ADCCP Programming Manual

Recovery Strategies
File-System Error Codes
069225 Tandem Computers Incorporated A–3
If a status probe of the LIU reveals a malfunction, CP6100 attempts to recover
according to the error. For instance, if the probe reveals that power has returned,
implying an earlier failure, CP6100 downloads the LIU. If the SYSGEN AUTOLOAD
parameter is set, other problems that the status probe revealed will also cause a
download. Applications can resume their use of the line after the download, with the
same considerations mentioned in this subsection.
Power Failures If a device seems unresponsive, the device may have had a power failure. The
following behaviors may indicate that a power failure has occurred:
An LIU that has lost power fails to respond to a status probe or to a frame sent by
CP6100. Application requests finish with error 124. If the LIU does not respond
after several attempts at recovery, CP6100 declares it down and requests finish
with error 66. When power returns, the operator must use CMI to start the line.
A controller that has lost power may cause timeouts on the I/O channel or a
failure by an LIU to respond to a status probe. This error may cause a path switch,
a download of the LIU, or both. If both controllers in a subsystem lose power,
requests finish every 30 seconds with error 231.
If a break-out board (BOB) (the device that connects a controller to a group of
LIUs) loses power, there are several possible symptoms. LIUs appear
unresponsive, as in the case of an LIU power failure, or a path switch occurs. as in
the case of a controller power failure.